Exam 2
1.
Describe the parts of a spermatozoan.
The head contains the sperm nucleus and acrosome
which contains digestive enzymes that eat through outer
layers of the ovum
The neck contains the mitochondria
the tail is the flagellum the propels the sperm
2.
Describe the structure of mammalian and echinoderm eggs.
Mammal (deuterostomate): The outer layer of the egg is
the zona pellucida. This layer may contain receptors that
will bind to spermatozoa
Echinoderm (protostomate): The outer layer in the egg is
the vitelline layer, surrounded by a jelly layer
Both: the plasma membrane will be internal to the zona
pellucida, or vitelline layer
Both: associated with the plasma membrane will be
numerous vesicles called cortical granules
3.
4.
5.
Describe fertilization events. Sperm swim to ova, bind to receptors. Receptors trigger the rupture of
acrosome and the elongation of the sperm cell to penetrate towards the ova plasma membrane. Sperm and
ova fuse and the sperm nucleus is forced into ova (fertilization has occurred). A cortical rxn is triggered.
Describe the cortical reaction and what does it accomplish? How does it differ in mammals and
echinoderms?
a. The cortical reaction protects the ovum from becoming polyploid. Once a sperm fuses with the
plasma membrane it triggers the cortical reaction. Cortical granules bind to the plasma membrane
and spew their contents into the space between the plasma membrane and zona pellucida / vitelline
membrane.
i. Mammals: alters the texture of the zona pellucida making it impenetrable.
ii. Echinoderms: alters the vitelline membrane causing it to expand, pushing away sperm before
becoming rigid and impenetrable.
Contrast radial and spiral cleavage.
Cleavage and subsequent cell divisions: reduces cell size,
and increases cell number for future differentiation
Spiral cleavage: oblique, ancestral characteristic, typical
of Protostomates
Radial cleavage: stacked on top of each other, typical of
Deuterostomates.
6.
Describe the relationship between the following: morula, blastula, ectoderm, endoderm, mesoderm, gastrula,
blastopore.
Gastrula – when the blastula invaginates and forms a
pocket. This embryonic tissue will give rise to adult tissues
including
1. endoderm – lining of gut and digestive organs
2. ectoderm – give rise to skin, hair, nails, and
nervous tissue
3. mesoderm – middle tissue, bones, muscle,
connective tissue, and coelom
Morulation – solid mass or disc of blastomeres
Blastula – (blastodisc) when the morula has a fluid filled
center. The fluid filled center is called a blastocoele
7.
In which stage of embryonic development mentioned in the previous question does gut and coelom
development (if the animal is to have a coelom) begin? The coelom will develop during gastrulation
8.
Describe how the following animals are different: acoelomic, Pseudocoelomic, eucoelomic.
Pseudocoelomic – body cavity not
completely lined by muscle or
connective tissue
Describe schizocoelomic and enterocoelomic development.
Acoelomic – triploblastic w/o
coelom
9.
Eucoelomic – body cavity
completely lined by muscle or
connective tissue
Schizocoelous – masses of mesoderm form
during gastrulation. A cavity forms within the
mesoderm forming coeloms. Similar to how
the morula forms a blastula
Enterocoelomic – during gastrulation, the
archenteron forms pouches that will pinch off
creating hollow spheres which will expand to
form coeloms.
10.
11.
What are ectoderm, endoderm, and mesoderm? Answered in question 6
What three events take place during gastrulation?
a. Formation of embryonic tissues that will develop into adult tissues – endo, meso and ectoderm
b. The archenteron (gastrocoele) forms. The initial opening where the blastula invaginates will develop into an
opening for the digestive cavity. If it’s the only opening, it’s a closed digestive tract.
c. Coelom development – the internal body cavity that lacks an opening to the outside. The coelom is lined by
muscle and connective tissue.
12.
Describe tissues, organs, and organ systems. Name the eleven organ systems of mammals.
a. Tissue level development – animals have tissues but lack organs
b. Organ level development – have tissues and organs, but lack organs systems
c. Organ system development – have tissues organs and organs systems
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
13.
14.
15.
16.
17.
18.
19.
20.
integumentary system
muscular system
skeletal system
nervous system
excretory system (nitrogen wastes)
digestive system
immune system
cardiovascular system
reproductive system
lymphatic system
endocrine system (hormones)
What are the types of symmetry?
a. Asymmetry (amorphous) – without symmetry
b. Radial symmetry – multiple planes of symmetry, like a pie
c. Bilateral symmetry – only one plane of symmetry, like mammals
How are open and closed digestive systems different? Closed system has one opening for entry and exit.
Open systems are like a tube, there’s a hole on either end.
Describe the relationship between the following: ectothermic, endothermic, heterothermic, homeothermic,
poikilothermic, warm blooded, cold blooded.
a. Ectothermic – body temps require external environment
b. Endothermic – physiological mechanism maintains body temp
c. Heterothermic – core temperature fluctuates
d. Homeothermic – core temperature remains steady
e. Poikilothermic – endothermic heterotherm - animal whose body temperature fluctuates
f. Warm blooded – typically endothermic homeotherms (with exceptions)
g. Cold blooded – typically ectothermic heterotherms
Describe the characteristics of the Metazoa. Metazoa represents a monophyletic clade. Multicellular
heterotrophs, lacking a cell wall, and showing some level of cell specialization.
Describe the evolutionary relationships and characteristics of the major metazoan clades discussed in
lecture: know their physical characteristics, know who is related to whom, which clades are
polyphyletic, and which terms designate formal taxons and which are descriptive.
When did the Metazoa evolve? Metazoa evolved approximately 700 ma in the Upper Proterozoic era of the
Precambrian eon. Known as the Ediacarian epoch
How do Porifera feed and reproduce?
a. Poriferans feed by filtering water for organic debris and phagocytize.
b. Most sponges can reproduce asexually. A small piece can grow into a complete sponge. Some
produce structures called gemmules which grow into a new sponge
c. Most are hermaphroditic, choanocytes produce sperm, and/or choanocytes or amoebocytes form ova
d. Sperm fertilizes ova in the mesenchyme  develops into a ciliated amphiblastula larvae  breaks
out into the spongocoele and out the osculum and becomes a sponge
Describe the characteristics and relationships between the following: Metazoa, Parazoa, Porifera, Calcarea,
Hexactinellida, Desmospongidae, Sclerospongidae.
a. Kingdom Metazoa
i. Subkingdom Parazoa – (next to the animals) contains only 1 major phylum
1. Phylum Porifera - sponges
a. Class Calcarea – calcareous sponges, spicules of CaCO3, Scypha, Grantia
b. Class Hexactinellida – Glass sponges, spicules of fused silicon, 6 pronged
c. Class Desmospongidae – bash sponges, spicules of unfused silicon, contains
sponging. Used for commercial sponges
d. Class Sclerospongidae – hard sponges, spicules of silicon with a shell of
CaCO3, deep water sponges
Calcarea
Hexactinellida
Desmospongidae
21.
Describe the relationship between the following: mesoglea, mesohyl, mesenchyme, amoebocytes,
pinacocytes, choanocytes, spicules, silicon, calcium carbonate, spongin, spongocoele, radial canal, ostia,
asconoid, syconoid, leuconoid.
a. Mesenchyme – (mesohyl, mesoglea), a gelatinous matrix in which cells are imbedded in
b. Amoebocytes – secrete spicules, spongin, and probably mesenchyme, and may form gametes
c. Pinacocytes – epidermal or pinacodermal cells that line the outer and inner surfaces of the sponge,
lacks a basement membrane, not true epithelial tissue
d. Choanocytes – flagellated cells that line the spongocoele of the sponge. Creates a flow of water
through the porocytes, through the spongocoele and out the osculum
e. Spicules – act as an internal support structure for sponge cells, are of specific composition (silicon or
CaCO3), secreted by amoebocytes
f. Spongin – an elastic protein that gives a commercial sponge its spongy texture. Desmospongidae
g. Spongocoele – (atrium), the internal chamber of a sponge, not a digestive tract
h. Radial canal i. Ostia – ostiem (porocytes), allow water to enter the spongocoele
j. Asconoid – simplest, have a large single spongocoele
k. Syconoid – have side chambers to the central spongocoele
l. Leuconoid – most complex, have side chambers coming off the spongocoele’s side chambers
22.
Do Poriferans have tissues? Explain. Poriferans lack well developed tissues. They lack true epithelium
tissue, and lack the protein collagen. The specialization of cells is low and embedded in a mesenchyme.
Protostomates
Deuterostomates
1.
2.
3.
4.
5.
6.
1.
2.
3.
4.
5.
6.
spiral cleavage
determinate blastomeres (at 32 cells)
mouth forms from the blastopore of the gastrula
they’re schizocoelous (coelom develops from mesoderm)
dorsal heart (if present)
ventral nerve chord
radial cleavage
indeterminate blastomeres (at 32 cells)
anus forms from the blastopore of the gastrula
they’re enterocoelous (coelom pinches off archenteron)
ventral heart
dorsal nerve chord
23.
Describe the characteristics and relationships between the following: Metazoa, Eumetazoa, Radiata,
Cnidaria, Hydrazoa, Scyphozoa, Cubozoa, Anthozoa, Ctenophora, Placozoa.
a. Kingdom Metazoa
i. Subkingdom Eumetazoa
1. branch Radiata – diploblastic, radial symmetry
a. Phylum Placozoa – known from only marine aquaria. Doesn’t fit anywhere??
b. Phylum Ctenophora – (comb
jellies) lack cnidocytes, jellyfish
like appearance, swim with 8 rows
of ciliated cells called comb rows,
have adhesive cells to capture small
inverts on long tentacles, mouth is
anterior, most bioluminescent
c. Phylum Cnidaria – jelly fish, sea anemones, corals, radial symmetry, show tissues, but not
well developed organs, diploblastic. Medusa form has a posterior mouth. Ectoderm Musculoepithelial cells are covering cells with contractile properties for movement and prey
capturing. Nerve cells for a nerve net for coordinated movement. Ocelli are clusters of light
sensitive nerve cells, Cnidocytes are stinging cells and contains nematocysts that harpoon their
prey. Endoderm – forms inner layer, digestive tract, secretes digestive enzymes into the
coelenteron. Between the two layers is a secreted protein called mesoglea (the jelly of the
jellyfish)
i.
Class Hydrazoa – polyp, fresh water, have stinging tentacles, sessile (non motile),
some form colonies. Hydra, Obelia, Physalia (Portugese man-o-war)
ii.
Class Scyphozoa – jelly fishes, medusa, free swimming (pelagic), phototropism,
posses ocelli
iii.
Class Cubozoa – box jellies, the most toxic animals on the planet
iv.
Class Anthozoa – (flowering animals), corals and anemones, do not alternate
between medusa and polyp forms
Hydrazoa
Hydra
Scyphozoa
Obelia
Physalia
Anthozoa
Cubozoa
nematocysts contain a coiled tube that
explodes out of the cnidocyte when the
cnidocil is triggered. The coiled tube
contains a toxin. Nematocysts can only
be used once. Some flatworms and
mollusks are able to eat cnidarians
without discharging the nematocysts and
transfer the cnidocytes to other regions
on there body to use for protection.
24.
Compare polyps and medusae.
Polyp – cylindrical, sessile (benthic), little mesoglea,
anemones and corals. Mouth is anterior
Medusa – pelagic (swimming), posterior mouth, thick
mesoglea, jellyfish
Many Cnidarians show both forms during their life cycle
25.
Describe the life cycle of a true jelly (Schyphozoa).
a. Eggs and sperm produced by adult medusae w/i testes and ovaries and released in the water where
fertilization occurs.
b. Zygote divides and forms a larva called a planula. Ciliated free swimming stage
c. Planula swims, and settles on the ocean floor and develops into a feeding polyp called Scyphistoma
d. Scyphistoma begins to section itself into several medusae called the Strobila in this stage
e. Medusal forms develop from the Strobila, dislodge and swim off as Ephyra and will develop into a
mature medusa.
Planula
26.
Scyphistoma
Strobila
Ephyra
Describe the characteristics and relationships between the following: Metazoa, Eumetazoa, Bilateria,
Acoela, Platyhelminthes, Digenea, Monogenea, Turbellaria, Trematoda, Cestoda.
a. Kingdom Metazoa
i. Subkingdom Eumetazoa
1. Branch Bilateria – exhibit bilateral symmetry, are triploblastic
a. Infrakingdom Acoela – triploblastic, acoelomic, not monophyletic
i. Phylum Platyhelminthes – flat worms, closed digestive system(when present). Flagellated
cells called flame cells move fluids through excretory canals. Nervous system: most show
cephalization with anterior ganglion. Nervous sys = nerve ladder. Reproduction: most
hermaphroditic, most have copulatory organs
1. Class Turbellaria – free living flatworm. Have ocelli clusters that look like eyes.
Locomote via cilia on the bottom surface, glide over mucus they secrete. Have a
proboscis / pharanx for feeding.
2. Class Cestoda – tapeworms, all members parasites. Body plan includes scolex (head),
neck and strobilus - which is composed of numerous proglottids. Each proglottid is a
reproductive unit. Lack a gastrovascular cavity, feed by absorbing digested nutrients from
the host. Includes Taenia saginata – human beef tapeworm, Dipyllidium caninum – dog
tape worm
3. Class Trematoda – flukes
a. Subclass Digenea – all members parasitic, lack hooks, have two suckers. Includes:
Opisthorchis sinensis – Chinese liver fluke, Schistosoma mansoni – blood fluke.
b. Subclass Monogenea – mostly parasites on the gills of freshwater fishes, have
hooks associated with posterior suckers.
27.
28.
Turbellaria flatworms
Cestoda tapeworm
Trematoda flukes
Describe the relationship between the following: scolex, strobila, proglottid.
a. Scolex – the head of a tape worm
b. Strobila – the sum of all proglottids
c. Proglottid – each proglottid is a reproductive unit capable of producing thousands of eggs.
Describe the life cycles of Opisthorchis, Schistosoma, Taenia, and Dipyllidium.
a. Opisthorchis – Chinese liver fluke.
humansnailfishhuman
i. Adults in human liver & intestine
ii. Worms copulate – fertilize eggs and deposit them within the feces
iii. Eggs hatch in water or consumed by snail. hatchling is called
miracidium larva
iv. Miracidium larva burrows into soft tissue of a snail, goes through
asexual phases
v. Miracidium develops into a sporocyst, within the sporocyst redia
develops
vi. Within redia, cercaria larva develop which ruptures the redia and
sporocyst
vii. Burrows out of the snail, and encysts in the muscle of a fish –
infective stage to humans
b. Schistosoma – Blood fluke
humansnailhuman
i. Adults in blood vessels of intestine - female sits in groove of larger
male and fused together
ii. They migrate to vessels of rectum and lay eggs.
iii. Sharp hooked eggs breaks the capillaries into rectum lumen – eggs in
feces
iv. Miracidium larva burrows into a snail – develops into sporocyst
which has more sporocysts within (no redia) within the secondary
sporocyst cercaria larvae develops
v. Cercariae ruptures the primary and secondary sporocysts & burrows
out of the snail
vi. Swims to human and burrows through the skin into blood stream.
Migrates to vessels of the intestine and mature
29.
c. Taenia – human beef tapeworm
humancowhuman
i. Adults in intestines, deposits the eggs in feces
ii. Eggs ingested by cows and hatch in their intestines
iii. Larva burrows into bloodstream to muscle tissue
iv. Forms a “bladderworm” larval stage in muscle
v. Humans ingest poorly cooked meat – excyst in intestine
d. Dipyllidium – dog tapeworm
dogsfleahuman (accidental)
i. Adult worms in dog intestine, deposits the eggs in feces
ii. Eggs ingested by flea larva – flea matures
iii. Worm larva encysts in flea muscle
iv. Dog eats flea while grooming
v. Humans can be accidental hosts if they ingest flea parts
Name and describe the characteristics of the Protostomia, Deuterostomia, Ecdysozoa.
1. Infrakingdom Protostomia – protostomates and animals with protostomate and deuterostomate
features. Includes Superphylum Ecdysozoa, and Lophotrochozoa
a. Superphylum Ecdysozoa – animals with an exoskeleton that must be shed for growth; ecdysis
is hormonally controlled
Infrakingdom Protostomates
Infrakingdom Deuterostomia
1.
2.
3.
4.
5.
6.
7.
1.
2.
3.
4.
5.
6.
7.
30.
spiral cleavage
determinate blastomeres (at 32 cells)
mouth forms from the blastopore of the gastrula
they’re schizocoelous (coelom develops from mesoderm)
dorsal heart (if present)
ventral nerve chord
triploblastic
radial cleavage
indeterminate blastomeres (at 32 cells)
anus forms from the blastopore of the gastrula
they’re enterocoelous (coelom pinches off archenteron)
ventral heart
dorsal nerve chord
triploblastic
Describe the characteristics and relationships between the following: Metazoa, Eumetazoa, Bilateria,
Protostomia, Ecdysozoa, Nematoda, Gastrotricha, Rotifera, Acanthocephala, Nematomorpha, Onychophora,
Tardigrada.
a. Kingdom Metazoa
i.
Subkingdom Eumetazoa
1. Branch Bilateria
a. Infrakingdom Protostomia – includes Superphylums Ecdysozoa, and Lophotrochozoa
i. Superphylum Ecdysozoa - animals with an exoskeleton that must be shed for growth;
ecdysis is hormonally controlled
1. Phylum Nematoda – round worms, open digestive tract, Pseudocoelomic, one of the
most numerous animals in terms of sheer numbers, free living and parasites,
dioecious. Includes: Trichinella, Enterobius (pinworm), Ascaris,
Ancylostoma(hookworm)
2. Phylum Gastrotricha – common freshwater predator
3. Phylum Rotifera – common freshwater predator. Have two large circular masses of
cilia for feeding & locomotion. Have a mastax (to crush food)
4. Phylum Acanthocephala – intestinal parasite with spiny proboscis
5. Phylum Nematomorpha – horsehair worms
6. PhylumOnychophora – walking worms. Tropical predator in leaf litter. Possible link
between annelids and arthropods with traits from each
a. have walking appendages, but lack jointed exoskeleton
b. have antennae, and arthropod heart
c. body is soft and segmented like annelids, but is chitinous like arthropods
7. Phylum Tardigrada – slow walkers – water bears. Small freshwater and marine
herbivores, often found on lichens and mosses. Tolerates extreme heat and cold.
8. Phylum Arthropoda – joint footed animals. Characteristics include:
a. have a chitinous, jointed exoskeleton
b. embryonic segmentation that persists through adulthood. Some segments
repeat structures, other segments develop unique structures
c. complex sensory organs, nervous system and muscular system
d. non cellular chitinous exoskeleton that must be shed to grow
e. Haemocoele present. Blood circulates in the coelom. Open circulatory sys
f. Many exhibit complex social behavior
Gastrotricha
Rotifera
Acanthocephala Nematomorpha Onychophora
Tardigrada
31.
Describe the life cycles of the following Nematoda: Trichinella, Enterobius, Ascaris, Ancylostoma (Necator),
Wuchereria.
a. Trichinella – trichinosis, common in rodents and pigs. Adults in intestine, female bears live larva, larva
immediately leaves the intestine burrows into blood vessels and migrates to skeletal muscle or joints and encysts.
The next host ingests larva by eating raw or poorly cooked muscle
b. Enterobius – pinworm, common in kids. Adult worms in rectom, female migrates to anus and explodes with eggs.
Eggs ingested by next or same host.
c. Ascaris – normally parasites of pigs. Adults in intestine, deposits eggs in feces – eggs ingested by next or same
host. Larva hatch and escape the stomach and intestine via the bloodstream. Migrage to the airspace in lungs,
crawl up trachea, larva swallowed into stomach, mature in intestine
d. Ancylostoma – hookworm, common in kids in South US. Adults in intestine, female bears and deposits live larva
in feces, larva in soil, burrows through skin into bloodstream, migrate to air space in lungs, crawls up trachea,
larva swallowed into stomach , mature in intestine.
Trichinella
Enterobius
Ascaris
Ancylostoma
32.
Be able to describe the characteristics and relationships of the unshaded Arthropod clades discussed in
lecture and laboratory, and be able to identify examples of each.
a. Phylum Arthropoda
i. Subphylum Trilobita – trilobites, all members extinct
ii. Subphylum Chelicerata – lack entennae. First two appendages modified; chelicerae (1st), pedipalps
(2nd), book gills or book lungs, 4 pair of walking legs, 2 body regions; cephalothorax and abdomen
1. Class Merostomata – horseshoe crabs. Ancient group harvested for their blood which
contains LAL (Limulus Amoebocytes Lysate), used for sterilizing medical equipment.
They have a long telson.
2. Class Arachnida – spiders, ticks, scorpions, mites, harvestmen, vinegaroons.
3. Class Pycnogonida – sea spiders. 4-6 legs, tiny cephalothorax. Odd group, feed on soft
bodied inverts like cnidarians
Merostomata
Arachnida
Pycnogonida
iii. Subphylum Crustacea – 2 body parts; cephalothorax and abdomen. Cephalothorax usually protected by
a shield structure called a carapace. 2 pair of antennae. 4 or more pair of walking legs
1. Class Branchiopoda – “gill feet” includes fairy shrimp and water fleas. Mostly fresh water.
Many thoracic appendages for swimming and modified into gills
2. Class Copepoda – very long first antennae held at right angles. Tail is biramus, many
appendages are biramus.
3. Class Cirripedia – barnacles. Free-swimming larva shows jointed chitinous exoskeleton. In
adults, arthropod characteristics are shown in their cirri (feeding appendages)
4. Class Malacostraca – Posses a rostrum, carapace, abdomen, and telson
a. Order Decapoda – shrimp, lobster, crap. 5 pair of abdominal legs, and 5 pair of thoracic
appendages for grasping or walking
b. Order Isopoda – rolly-pollys. Carapace absent, dorsoventrally flattened. No Distinction
from thoracic and abdominal segments. Marine parasites, and some terrestrial forms
c. Order Amphipoda – similar to isopods, but laterally flattened. Shrimp like in
appearance. First few segments fused with head. Some parasites, commensals.
d. Order Euphausiacea – krill, shrimp-like inverts. Very pivotal & widely consumed
organisms in the ocean food chains.
Branchiopoda
Copepoda
Cirripedia
Malacostraca
iv. Subphylum Uniramia
1. Class Insecta / Hexapoda – 800,000 species. 3 body regions; head, thorax and abdomen One
pair of antennae, 3 pair walking legs, compound and simple eyes. No lungs, they have spiracles
which are openings to the inside, as insect moves air moves through the spiracles
a.
b.
c.
d.
e.
f.
g.
h.
i.
j.
k.
l.
Anoplura
Coleoptera
Isoptera
Chilopoda
Order Anoplura – sucking lice
Order Coleoptera – beetles, weevils
Order Dermaptera – earwigs
Order Diptera - flies, mosquitos one pair of wings
Order Hymenoptera – ants, bees, and wasps. Two pair of wings
Order Hemiptera – true bugs, bedbug. Thoracic triangle, wings flat on body
Order Homoptera – leafhoppers, cicadas wings tent-like over abdomen
Order Isoptera - termites
Order Lepidoptera – butterflies and moths
Order Odanata – damselflies, dragonflies 2 pair of wings held horizontally
Order Orthoptera – crickets, roaches, grasshoppers, mantids
Order Siphonaptera – fleas
Dermaptera
Diptera
Hymenoptera
Hemiptera
Homoptera
Lepidoptera
Odanata
Orthoptera
Siphonoptera
2. Class Chilopoda – centipedes. 1 pair of legs per body segment, dorsoventrally flattened
3. Class Diplopoda – millipedes. 2 pair of legs per body segment. Circular cross section
Diplopoda
33.
What are characteristics and relationships of the Lophotrochozoa, Trochozoa, Lophophorata, Nemertea
Mollusca, Annelida, Bryozoa, Brachiopoda, Pogonophora, Phoronida, Chaetagnatha?
a. Superphylum Lophotrochozoa
i. Supraphylum Trochozoa
1. Phylum Nemertea (Rhynchocoela) –
Rhyncho = snout. Common name – proboscis
worms. Triploblastic, acoelomic, although
proboscis is eucoelomic, open digestive sys.
Posses closed cardiovascular system.
Resemble flat worms but usually have a
feeding structure used to capture prey.
2. Phylum Mollusca – common name -- soft bodied animals. Most lack segmentation. Well
developed open circulatory system with a heart, well developed nervous system. Octopus
is the most intelligent invertebrate. All members posses a radula – a rasp-like plate in
mouth used for scraping food; a mantle – a layer of cells that secrete a shell CaCO3, and
contains gills and siphons; a muscular foot – used for locomotion
a. Class Gastropoda – (stomach footed), snails and slugs, practice internal &
external fertilization.
b. Class Pelecypoda / Bivalvia – (spade footed), clams, oysters, shipworms.
Practice external fertilization
c. Class Polyplacophora – chitons, have 8 overlapping plates, external fertilization
d. Class Scaphopoda – (tusk footed), shell open at both ends. Shell looks like tooth
or tusk
e. Class Cephalopoda – (head footed), octopuses, squid, cuttlefish. Most intelligent
invertebrates. Complex social behaviors, problem solvers. 8 suckered arms, squid
also have 2 tentacles to capture prey. Excellent vision. Posses chromatophores
which allow color change for cryptic functions, and convey emotional state. Some
fertilize via a spermatophore, some squids fertilize via a penis.
Gastropoda
Pelecypoda / Bibalvia
Polyplacophora
Scaphopoda
Cephalopoda
3. Phylum Annelida – segmented worms. Triploblastic, eucoelomic, open digestive
system, protostomate, good circulatory system. They demonstrate metamerization – their
body is divided into definite segments called somites or metameres, which may aid in
body organization
Segments are divided internally by septa, segments posses bristles called setae for
locomotion. Most show trochophore larvae in reproduction
a. Class Oligochaeta – (few bristles) the earthworms, have enlarged region 1/3 back
called the clitellum, can grow to 4-5 feet in S. America
i. Reproduction: worms crawl past each other in opposite directions, sperm
is released from the sperm ducts to the sperm receptacles of the other
worm. Eggs and the stored sperm from the other worm are deposited into a
mucous sac where fertilization occurs. Mucus sac produced by clitellum.
b. Class Polychaeta – (many bristles) polychaetes, mostly marine in the sand. The
most numerous annelid, thousands of species. Have specialized appendages for
gas exchange and locomotion called parapodia. In environmental studies, they’re
an indicator of effects of pollution.
c. Class Hyrudinea – leeches, have a posterior sucker for attachment. Feed with
mouth, slice skin, suck blood. Reproduction similar to oligochaetes.
Oligochaeta
Polychaeta
Hirudinea
ii. Supraphylum Lophorata – most posses a 3 part body and U-shaped digestive tract. Some lack
a coelom, and some have a feeding structure called a lophophore. May be polyphyletic.
1. Phylum Bryozoa – moss animals. Benthic, marine animals that look like corals or
crustose sponges. They secrete a CaCO3 shell around themselves.
2. Phylum Brachiopoda – arm footed. Look like bivalves because they have two shells.
Brachiopods have a stalk that attaches to a surface. Some link them to echinoderms.
3. Phylum Pogonophora – tube worms. large woms that secrete a chitinous tube around
themselves. Associated with deep ocean thermal vents
4. Phylum Phoronida – tube worms that are close relatives to Bryozoa and Bachiopods.
Have a U-shaped intestine called horseshoe worms. Can be abundant in shallow
seas/lagoons
5. Phylum Chaetognatha – arrow worms. Close relatives to Bryozoa and Brachiopods but
lost their lophophore, but retain the three part body plan. Aggressivepelagic predators,
lack a circulatory system, ventral ganglia.
Bryozoa
34.
Brachiopoda
Pogonophora
Phoronida
Chaetognatha
Be familiar with all Lophotrochozoa clades, including relevant classes, and their characteristics.
35.
What are characteristics of the Echinodermata and its subclades? The spiny skinned animals. Sea stars etc. true
deterostomes, exibit pentamerous symmetry, posses a water vascular system (tube feet). Asteroidea, and
Echinoidea have pedicillaria (grasping structures that grab larval parasites and pass to mouth.
Crinoidea
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38.
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40.
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Asteroidea
Ophiuroidea
Echinoidea
Holothuroidea
What is the relationship between Echinoderms, and chordates? Both are Phylums under Deuterostomia.
What is the relationship between the Hemichordata and the Chordata? Hemichordata is possibly the
evolutionary link to chordates. They develop gill slits like chordates in their embryonic development.
Be familiar with the characteristics and evolutionary relationships (and time of appearance) of the
unshaded chordate clades discussed in lecture and laboratory.
a. Infrakingdom Deuterostomia
i. Phylum Chordata – posses a dorsal hollow nerve cord. Presence of a notochord (rod of support
tissue for nerve cord). Presence of pharyngeal clefts (gill slits in fish, upper and lower jaw in mammals)
1. Subphylum Urochordata – tunicates, or sea squirts. Only the pelagic larval form shows
the nerve cord and notochord. Undergoes metamorphosis into adult form. Adults are
benthic filter feeders, gill acts as screen for filtering seawater
2. Subphylum Cephalochordata – lancelets. Have a notochord, filter feeders that stick tail
in the sand with mouth exposed. Lack a skeletal system. Date back to dawn of animals.
When do the Chordata first appear in the fossil record? Chordates began to show up in the late Cambrian
Describe the relationship of the following terms to one another: oviparous, ovoviviparous, and viviparous. Give
examples of animals that practice each.
a. Oviparous – an animal that lays an amniote egg (birds, reptiles, monotremes)
b. Ovoviviparous – an animal that produces an egg that develops and hatches within the mothers body.
The young are born alive and the shell is then expelled (white sharks, rattle snakes)
c. Viviparous – don’t produce eggs, bear live young. This is typically the mammals with the exception of
monotremes (echidna, platypus)
Compare how the Chondrichthyes and Osteichthyes manage the problem of buoyancy.
a. Chondrichthyes – are the cartilaginous fishes which includes sharks rays ratfish etc. The manage the
buoyancy problem by producing oils within their extra large liver
b. Osteichthyes - are the boney fishes. They manage the buoyancy problem with a swim bladder. This is a
gas filled bag to which gas is added or reabsorbed. This is more efficient than chondricthyes. Maintaining
the right buoyancy allows the fish to remain at a certain depth without swimming or using energy.
Chondricthyes
Osteichthyes
42.
Describe the characteristics, functions, and relationships between the following; capillaries, veins, venules,
arteries, arterioles, atrium, ventricle, heart.
a. Arteries have thick walls, carry blood from the heart, and split into arterioles, High blood pressure
i. Arterioles have thinner walls than arteries and split into capillaries
1. capillaries very thin walls and are the site of gas / waste exchange. Drain into venules, Low B pressure
ii. Venules – drain blood into veins
b. Veins – empty blood into atria of heart. Walls are relatively thin, blood pressure is very low
i. The heart is composed of two parts. The atrium receives blood from the lungs and body, and the
ventricle pumps blood to the lungs and body.
43.
Describe blood flow in a two-chambered heart, a three-chambered heart, and a four-chambered heart.
a. Two chambered heart – fishes, one ventricle and one atrium. The ventricle sneds blood to the gill capillaries,
the capillaries diffuse pressure, from gill capillaries blood flows into larger vellels that go to the general
circulation, this blood is oxygenated but under low pressure which limits the volume of blood and thereby
oxygen causing this animal to be ectothermic
b. Three chambered heart – amphibians and reptiles, one ventricle and two atriums. The right atrium receives
deoxygenated blood from general circulation, the left atrium receives oxygenated blood from the pulmonary
circulation. Oxygenated and deoxygenated blood mix in the ventricle (although their densities keep them
somewhat separate). Blood from the ventricle splits and goes to the lungs or general circulation. The blood being
pumped from the ventricle is at low pressure to avoid rupturing capillaries in the lungs. This limits the volume of
blood and thereby oxygen causing this animal to be ectothermic
c. Four chambered heart – mammals, aves, two ventricles and two atriums. The right atrium receives
deoxygenated blood from general circulation via the anterior (superior) and posterior (inferior) vena cava. The
blood is then pumped into the right ventricle. The right ventricle then pumps blood via the pulmonary arteries to
the lungs to be oxygenated. Oxygenated blood from the lungs flows to the left atrium via pulmonary veins.
Blood is pumped into the left ventricle where the blood is pumped to the general circulation via the aorta. endothem
44.
45.
What is the relationship between hearts, blood pressure, body size, and endothermy?
a. Endothermic animals utilize physiological mechanisms to maintain core temperature. To be endothermic
the animal will require a large volumes of oxygenated blood that flows at high pressure from the heart.
A 4 chambered heart is capable of pumping blood at a high pressure, unlike the 2 or 3 chambered heart.
Body size is more related with homeothermy than endothermy.
Compare the amniote egg to the placenta, and describe their structures and functions, and why they are
considered homologous. The placenta derived (homologous) from the amniote egg evolutionarily. They share
many of the same membranes and tissues with modifications.
a. Amniote egg – has its own water and nutrient supply
i.
Embryonic membranes:
ii. Amnion – encloses embryo and secretes amniotic fluid (protective cushioning)
iii. Allantois – membrane is highly vascular, forms a surface for gas exchange through other egg
membranes and eggshell. Nitrogenous waste collects in the allantoic sac
iv. Yolk sac – encapsulates yolk, also vascular. Nutrients drawn into abdominal cavity of embryo
v. Chorion – encloses all other embryonic membranes
vi.
Extraembryonic (maternal ) structures:
vii. Shell – either leathery or hard calcareous layer for protection, permeable to air
viii. Egg shell membranes – collagenous fibers, protective, air permeable
ix. Egg albumin – egg white, cushions, supports
b. Placenta – embryonic membranes include:
i. Amnion – encloses embryo and secretes amniotic fluid (protective cushioning)
ii. Allantois – blood vessels develop, then degrades to mucoid connective tissue of umbilicus and placenta
iii. Yolk sac – becomes support tissue in umbilical cord
iv. Chorion – outermost layer of embryonic tissue that encapsulates the fetal capillaries, in fingerlike
extensions called chorionic villi
v.
Maternal structures include:
vi. Endometrium of uterus
vii. Maternal arterioles and venules
viii. Maternal poos, modifies capillaries form sinuses that bathe chorionic villi in maternal blood,
maternal and fetal blood doesn’t mix. Chorion and allantoic tissue provide barrier
46.
Describe the relationship between the following: Amphibians, Reptiles, Anapsids, Synapsids, Diapsids, Chelonia,
Squamata, Archosauria, Crocodilians, Dinosaurs, Ornithischia, Saurischia, Theropods, Sauropods, Ankylosaurs,
Hadrosaurs, Therapsids, Mammalia, Insectivora, Birds, Permian, Triassic, Permian Extinction, Cretaceous-Tertiary
Extinction, K-T Extinction.
a. Permian – amphibians dominate the fossil record. Diapsids prospered but were miner players in fossil record. A
major extinction took place at the end of the Permian.
b. Permian Extinction – aka P-T extinction. Approx 90% of marine species died. May have occurred due to the
formation of Pangaea (super continent)
c. Triassic – many amphibians died opening up niches for reptiles to fill. A massive reptile radiation occurred.
Synapsids gave rise to Therapsids (mammal-like reptiles) which gave rise to mammals. 230ma
d. Cretaceous-Tertiary Extinction – aka K-T extinction. Dinosaurs disappear, a group of Cephalopods called
Ammonites die. About 70% of species die. A meteorite is suspected to be a major factor in the extinction event,
but many factors contributed to the extinction. Mammals and birds survive the extinction and go through a
massive radiation there after.
e. Amphibians – frogs, toads, salamanders. Can exchange gas through skin (not keratinized), exhibit a
metamorphosis in development where lungs develop. Dependent on water for reproduction. Lungs are inefficient,
have a cloaca and excrete ammonia. Posses a three-chambered heart. Evolved from lobe finned fishes 370ma in
late Dovonian period.
i. Reptiles – evolved from amphibians 325 ma, late Mississippian of Carboniferous period
f. Anapsids – ancestral reptiles, their skull lacks a postorbital foramin
i. Synapsid – evolved from anapsids, have a single postorbital foramin
1. Therapsids – mammal-like reptile, gives rise to mammals
a. Class Mammalia – evolved from Therapsids 230 ma in late Triassic period. Have
keratinized skin / hair, viviparous, posses mammary glands. Endothermic homeotherms
(some poikilothermic). Most show placental development. Posses hertodont dentition
(different kinds of teeth in the mouth). Subclasses include Monotremata (egg laying
mammals), Marsupialia (have a pouch), and Eutherians (true placental)
i. Subclass Eutherians – have a true placenta
1. Order Insectivora – moles and shrews
2. Order Lagomorpha – rabbits and hares. Rabbits have altricial young
(helpless), hares have precocious young (eyes open able to walk / run)
3. Order Rodentia – chipmunks, squirrels, mice, rats etc.
4. OrderCetacea – whales
Insectivora
Suborder Fissipedia
Lagomorpha
Rodentia
Cetacea
5. Order Carnivora – dogs cats, bears, etc. includes the families:
a. Suborder Pinnipedia - fins
b. Suborder Fissipedia - legs
b. Family Felidae – cats
c. Family Canidae – dogs
d. Family Ursidae – bears
e. Family Mustelidae – weasels, otters, badgers, etc
Felidae
Canidae
Ursidae
Mustelidae
Ornithischia
ii. Diapsids – evolved from anapsids, have 2 postorbital foramins, gave rise to the following clades
during the Permian
1. Archosauria – ancestral to Dinosaurs. Gave rise to crocodiles, and gave rise to a clade of
reptiles known as the Thecodonts with gave rise to the Pterosaurs (flying reptiles) and the
two clades of dinosaurs.
a. Order crocodilian
b. Ornithischia - Bird-hipped dinosaur. The pubis doesn’t meet ventrally
(adaptation for egg laying), includes: Ankylosaurs (armored dino’s),
Hadrosaurs (duck billed dino’s), Stegasaurs, Iguanodons, Ceratopsids
c. Saurischia – Reptile-hipped dinosaur. The pubis meets ventrally.
Includes Tyranasaurus, Allosaurus, and Sauropods (huge long necked
herbivores). Theropods gave rise to the birds 220ma in the late Triassic
a. Aves – endothermic homeotherms, Oviparous, excrete uric
acid, have keratinized skin with feathers which are modified
Saurischia
scales. They posses a keeled sternum for attachment of
massive pectoral muscles. Have a 4 chambered heart, and a
very efficient respiratory system.
2. Order Squamata – snakes and lizards
3. Order Chelonia – turtles, considered retrograde Anapsids
Anapsid
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49.
50.
Synapsid
Diapsid
What is irony concerning dinosaur evolution and extinction? The irony is that theyflourished following a major extinction
(Permian), only to fall victim themselves to another extinction event (K-T)
What is a bird? Modern birds have the following characteristics
a. Endothermic homeotherms
b. Have keratinized skin with feathers (modified scales), posses keeled sternum, oviparous (amniote egg), posses a
cloaca, males have a copulatory organ, excrete uric acid. Posses a 4 chambered heart.
Describe the relationship between the posterior air sacs, lungs, and anterior air sacs. Bird respiration. Birds have air sacs
that protrude into various places including the bone marrow. These sacs increase surface area for gas exchange. They also
create a one way flow of air.
a. Outside air is goes to the posterior air sacs via the trachea
b. From posterior sacs the air goes to the lungs
c. From the lungs the air goes to the anterior air sacs
d. From the anterior air sacs, the air goes back outside.
i. This one way airflow allows the lung capillaries to carry blood
in the opposite direction.
What are the roles of the avian crop and gizzard? The crop functions like our stomach. Their stomach is highly reduced
and part of which forms the gizzard, which grinds food. (birds lack teeth and need a way to break food down.
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Describe the evolutionary relationship between the Monotremes, Marsupials, and Eutherians, and how their
radiation and distribution was influenced by plate tectonics.
a. Monotremes – egg laying mammals. These are the ancestral mammal and gave rise to the marsupials
160 ma in the Jurassic period of the Paleozoic era while the super continent Pangaea was intact
b. Marsupials – poorly developed placenta, bear live young. The mammillae is within a pouch where the
young develop. The evolved from the monotremes.
c. Eutherians – advanced placenta, no pouch. They evolved from primitive eutherians 20ma after the split
up of Pangaea. The evolved on the northern supercontinent which lost and regained Africa.
i. the ancestral mammals the Monotremes gave rise to the marsupials on the super continent
Pangaea. After Pangaea began to split up, the Marsupials gave rise to the eutherians on the
northern super continent. The eutherians radiated throughout Europe, Asia, Africa, and North
America out competing and displacing the Monotremes and Marsupials (with a few exceptions).
Australia was free of the Eutherians and the Marsupials and Monotremes still exist there. South
America eventually formed a land bridge to North America and the advanced placentals quickly
replaced most of it’s Monotremes and Marsupials.
Monotremes
Marsupials
Eutherians
Describe the stages of a typical population cycle?
a)
Lag phase – most populations exhibit a period of relatively slow growth.
b)
Once growth begins it can have certain characteristics:
i)
Linear growth – constant numerical growth. Doubling occurs slowly
ii)
Exponential growth – result of a growing numerical increase. Doubling occurs rapidly.
Populations grow exponentially when there are no limits on growth.
c)
Environmental resistance slows exponential growth
d)
Limiting factors set the carrying capacity (the number of individuals the environment can support).
i)
At this point one of two things happen: The population may stabilize, or the population may
crash. Some wild populations may fluctuate as carrying capacity fluctuates from year to year.
How is exponential growth different than linear growth?
a)
Exponential growth - result of a growing numerical increase. Doubling occurs rapidly: 2,4,8,16,32,64...
b)
Linear growth - constant numerical growth. Doubling occurs slowly: 2,4,6,8,10,12…
Describe the relationship of the following: carrying capacity, limiting factors, density dependent factors, density
independent factors, environmental resistance, and biotic potential.
a)
Carrying capacity – the number of niche spaces available. The total number of individuals the
environment can support without being detrimental to the environment.
b)
Limiting factors – inhibit the rate of growth and determine the carrying capacity of the population.
Includes two types
i)
Density dependent limiting factors – these are factors that will limit growth more severely as
the population increases in numbers or concentration. Examples include: food, social factors, disease
ii)
Density independent limiting factors – factors that effect population in a consistent way
whether there are few or many individuals. Examples include: weather, climate, geology, geography
c)
Environmental resistance – slows exponential growth
d)
Biotic potential – this is the potential maximum growth rate. This is rarely achieved in nature because
limiting factors produce environmental resistance and slows the growth of the population.
How does a population typically behave if resources are renewable, and if resources are non-renewable?
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a)
Renewable – if the environmental resources are renewable, the population may stabilize.
b)
Non-renewable – if the environmental resources are not renewable, the population may crash
What is earth’s human carrying capacity and how is it related to quality of life?
a)
Most popular estimates of human carrying capacity is 10-12 billion. However at a high standard of
living like we enjoy in the US, estimates range from <1 billion – 1.2 billion. When living conditions are
really low, high estimates of our carrying capacity are over 45 billion if certain conditions are met such as:
i)
Cultivating all arable land, mass conversion to nuclear power, expansion of mining
Is human population static, showing linear growth, or exponential growth? Explain.
a)
Human population is showing exponential growth. Our APGR is currently 1.2% per year. This means
that each year the population has grown more than the year before. A J-shaped curve on a chart.
Consider the following hypothetical population and compute the statistical measures below: #births = 50,000;
#deaths = 10,000; #immigrants = 5,000; #emigrants = 20,000; mid-year population = 1,000,000
a)
BR = (50,000/1,000,000) x 1000 = 50
b)
DR = (10,000/1,000,000) x 1000 = 10
c)
APGR = (50 – 10) /10 = 4.0%
d)
DT = 70 / 4.0 = 17.5 years
e)
NMR = ((5000-20,000) / 1,000,000) x 1000 = -15
f)
True Growth Rate = 4.0 + (-15 / 10) = -6%
g)
True Doubling Time = 70 / -6 = Will never double in these conditions.
What is TFR and why is it important? TFR - Total Fertility Rate. This is a projection of how many children a
woman will have in her lifetime, based on current trends. The world TFR is 2.8
Why is replacement value higher in LDC’s than MDC’s? More babies die to starvation or disease in LDC’s
a)
LDC – Less developed country
b)
MCD – More developed country
Draw age structure diagrams for rapidly growing, slow growing, and shrinking populations, and describe why
the bottom third of the diagram is indicative of future growth. The bottom third of the diagram shows the
children who will soon move up into the reproductive age of the chart and have children of their own.
What is AMA and how is it related to TFR? AMA – average marrying age. However, the term means the
average age a woman bears her first child. Statistics show the younger the woman is when she bears her first
child, the more children she will have. TFR (total fertility rate) would be affected if AMA is over 25
Compare APGR, DT, TFR, and age structure diagrams for MDC’s and LDC’s.
Population Feature
LDC’s (less developed countries) MDC’s (more developed countries)
APGR (annual percentage growth rate)
2.1%
0.6%
DT (doubling time)
35 years
105 years
TFR (total fertility rate)
4.4
2.0
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Age Structure
Fast growth
Slow growth
What are some philosophical and ethical considerations regarding human population control?
a)
Can we decide on optimum populations, as quality of life is extremely subjective?
b)
What is a tolerable population density?
c)
Will Americans tolerate changes in diet and food availability?
d)
What are acceptable decreases in energy availability?
e)
What are acceptable methods to reduce birth rate?
Describe common methods of birth control, and which are 100% effective? Methods of birth control includes:
Abstinence, rhythm method (avoiding intercourse around time of ovulation), Barrier methods (diaphragm,
sponge condoms), Hormonal methods (drugs, including RU-486), Spermacides, Sterilization (tubal ligation or
vasectomy), Abortion.
Only abstinence and abortion are 100% effective
What is RU-486 and how does it work? RU-486 is a method of birth control. It competes with progesterone for
binding sites on placental cell membranes. Progesterone is a hormone, which keeps placental cells alive when it
binds to progesterone receptors. RU-486 will cause the death of placental cells if it binds to the progesterone
receptors instead of progesterone.
What can be done to slow population growth?
a)
Women are the key. Educating women have fewer children statistically, because they typically want to
get through school and begin their career before having children
i)
Economic development – more developed countries (MDC’s) typically have less children.
Because the women become educated and delay childbirth
ii)
Empowerment of women
iii)
Family planning – families that are planned are smaller than those that are not.
iv)
Reproductive laws – such as China’s single child policy
Why is the education and empowerment of women key to slowing growth? . Educating women have fewer
children statistically, because they typically want to get through school and begin their career before having
children. Women who have children later in life have fewer children than those who have children earlier.
How has China been able to slow growth when other LDC’s have not? China has a one child policy and have
instituted incentives and penalties to get couples to agree to certain terms which will ultimately allow them 1 child
How is infectious disease different from non-infectious disease?
a)
Infectious disease – a biological organism called the agent of disease causes infectious disease.
b)
Non-infectious disease – lack an agent of transmission. Cancer, hemophilia, diabetes, etc
What are examples of agents of disease?
a)
Viral - HIV, measles, smallpox, flu, common cold. Etc.
b)
Bacterial – forms of dysentery, Chagas’ disease, Trichomonaisis etc
c)
Fungal – yeast infections, ringworm etc
d)
Parasitic worms – tapeworms, roundworms, flukes, etc
What is a vector transmitted disease and give examples? Agents are transmitted from one host to another by an
organism. These include: mosquitoes, ticks, flies, and most other biting insects.
Describe the difference between endemic, epidemic, and pandemic disease.
a)
endemic – present in a population in low numbers, maintained by carriers who are not affected
b)
epidemic – outbreaks in large numbers, in a virulent form
c)
pandemic – spreads throughout the world
Describe the difference between chronic and acute disease.
a)
Acute – intense and have short duration
b)
Chronic – less intense and of long duration
Give examples of non-infectious diseases, as well as examples of causes of non-infectious diseases.
a)
Non-infectious diseases - Cancer, hemophilia, diabetes, muscular dystrophy etc
b)
Causes of non-infectious diseases – chemicals, hereditary, radiation, combinations of heredity and
environmental factors
Describe the abiotic factors in an ecosystem. These are the non living parts of an ecosystem which includes:
a)
Atmosphere – the gaseous earth, 78% nitrogen and 21% O2. we live in the troposphere
b)
Hydrosphere – the aqueous earth, includes rivers, lakes, oceans, water vapor, ice and subterranean water
c)
Lithosphere – the rocky earth, includes rocks, soil, sediment, dust etc.
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d)
Energy – many forms, solar, chemical, mechanical, etc.
Describe the biotic factors in an ecosystem. These are the living parts of an ecosystem which includes:
a)
Organism – a single living thing
b)
Population – composed of organisms within a species
c)
Natural community – the interacting collection of populations in a given place and time
Define the word ecosystem, and what is the ecosphere? An ecosystem is a self-sustaining natural community of
organisms interacting with each other and their environment. The ecosphere a.k.a. the biosphere is the sum of
all the ecosystems.
What does the term niche mean? A niche is an organism’s job in the ecosystem. There is only so many niches
available in an ecosystem, and no two organisms may occupy the same niche within that ecosystem.
What is competitive exclusion? No two organism’s may occupy the same niche in the same ecosystem.
Be familiar with the regions/zones in marine and lentic ecosystems. Lentic systems are those of standing
surface water as in lakes and ponds. Lake water tends to stratify in Summer and mix in the fall and Spring
bringing nutrients to the surface.
Aphotic zone should be Profundal zone
Describe eutrophic, mesotrophic, and oligotrophic lakes.
a)
Eutrophic – have an abundance of nutrients making for lots of productivity.
b)
Mesotrophic – lakes that are intermediate in nutrients
c)
Oligotrophic – lakes that have minimal nutrients examples would include alpine lakes
Describe how eutrophication can lead to a “dead” lake. Too many nutrients can lead to eutrophication
a)
A temporary increase in nutrients can lead to an algal bloom
b)
Consumer populations explode
c)
Algae may overshoot the carrying capacity which leads to an algal crash
d)
Decomposers explode and deplete the lake of oxygen which leads to a massive fish crash which leads to
a further bloom of the decomposers
e)
Anaerobic bacteria blooms, and the lake is considered dead.
Describe characteristics of lotic ecosystems, and estuaries. ( Low - Flow) These systems include flowing water
a)
Includes, rivers and streams.
What factors influence vegetation in biomes? Vegetation is influenced by certain limiting factors such as:
a)
Temperature, Water availability, Soil type, General climate
86.
Describe general characteristics, including diversity and soil quality, of the following biomes: deciduous forests,
coniferous forests, chaparral, temperate grasslands, tropical grasslands (savannah), desert, tundra, tropical rain forest,
riparian habitats, wetlands.
a)
Deciduous forest – broad leaf forest, drops leaves in winter. Summers are hot and humid. Moderate diversity, soil
quality is excellent
b)
Coniferous forest – evergreen forest, summers are temperate; winters are cold, diversity low to moderate, fire
adapted, soil quality is poor
c)
Chaparral – scrub forest typical of SoCal, summers hot/dry; winters moderate and wetter, diversity low to
moderate, fire adapted, soil quality is poor
d)
Temperate grasslands – summers hot/humid; winters cold, diversity moderate to high, fire adapted, soil quality
is excellent
Deciduous
Coniferous
Chaparral
Temperate grasslands
e)
Tropical grasslands – savannahs, hotter than temperate grasslands, droughts more severe, fire adapted,
soil quality is excellent.
f)
Desert – hot, dry, low diversity, soil quality is poor
g)
Tundra – permafrost, short windy summers, cold windy winters, plants very low to ground with
minimal roots, diversity is low, soil quality is poor
h)
Tropical rain forest – hot and humid, massive rainfall, diversity high, soil quality is poor
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Tropical grasslands
Desert
Tundra
Tropical rainforest
Describe the first and second laws of energy.
a)
1st Law of Energy (thermodynamics) – energy is neither created nor destroyed, buut merely changes form
b)
2nd Law of Energy (thermodynamics) – some energy dissipates to the surroundings as heat as it flows or
changes form
Describe a fusion reaction. In a fusion reaction, isotopes of Hydrogen nuclei under conditions of extreme heat, collide and
fuse to form Helium nuclei. In this reaction mass is converted into a lot of energy E=mc2.
Why is it considered a nuclear reaction rather than a chemical reaction? It’s considered a nuclear reaction because it leads
to a change in the nucleus of an atom instead of the electron configuration (chemical rxn)
What happens to some of the mass of the particles in a nuclear reaction? The mass of the Helium nucleus is less than the
Hydrogen isotopes that fused to form it because some mass is converted to energy
Where is fusion occurring in our solar system? Fusion is taking place around the sun
Place the following parts of the electromagnetic spectrum in order from smallest
wavelength to longest wavelength: blue, x-ray, radio, orange, yellow, infra red,
ultraviolet, red, violet, radio, yellow, green, gamma. Gamma rays, X-rays,
Ultraviolet, Violet, Blue, Green, Yellow, Orange, Red, Infra red, Microwaves,
Radio waves
93.
What is the overall equation for photosynthesis?
6CO2 + 6H2O + 686Kcal  C6H12O6 + 6O2
94.
What can plants do with solar energy that animals cannot? Animals can use solar energy and convert it into
chemical energy in the process of photosynthesis
What can plants do with carbon dioxide and water that animals cannot? With energy from the sun, plants create
organic molecules with carbon dioxide and water, with oxygen as a bi-product
Why are plants considered producers in food chains? They’re called producers because they producers of
organic molecules and are on the bottom of all food chains. Plants produce more energy than they consume.
What are consumers, and why do they “consume?” Consumers are called “consumers” because they cannot
photosynthesize and must consume other organic molecules for the energy they contain.
Label the members of the following food chain as producers, and the appropriate consumer, i.e. primary,
secondary, tertiary, etc: flower nectar is eaten by a butterfly, which is eaten by a frog, which is eaten by a snake,
which is eaten by a red tailed hawk.
a)
Flower – producer
i)
Butterfly – primary consumer
a)
Frog – secondary consumer
(1)
Snake – tertiary consumer
(a)
Red tailed hawk – quaternary consumer
What are higher order consumers in the example above? The frog, snake, and hawk, are higher order
consumers. Anything past the primary consumer is a higher order consumer.
What is a food web? Individual food chains may overlap forming food webs. Animals may be prey in several
different food chains, and predators will have several different prey animals
Describe what the terms herbivore, carnivore, and omnivore mean, and give examples of each.
a)
Herbivore – animals that primarily eat plants such as: cows, horses, deer, rabbits
b)
Carnivores – animals that primarily eat other animals such as: cats, snakes, wolves
c)
Omnivores – animals that have a relatively balanced diet of plants and animals such as: people
d)
Detritivores – animals that feed on decaying animals such as: vultures
Describe an energy pyramid, and what is a trophic level. An energy pyramid is a representation of the energy
distribution in an ecosystem. They pyramid is widest at the bottom where the producers are, and tapers towards
the top where the higher order consumers are.
What is the “10% rule” of nature? Only 10% of the energy at one trophic level moves up the pyramid to the
next trophic level. 90% of the energy dissipates to the surroundings.
How much energy in an ecosystem goes from one trophic level to the next, and what happens to the rest of the
energy? 10% goes to the next level. 90% dissipates to the surroundings
What fraction of the energy originally in grain is held in human tissues if we do the following: grain is fed to
chickens, when chickens die they are ground up in cattle feed and fed to cattle, and the cattle are eaten by
humans. We would receive only 1/1000th of the energy in the grain.
What fraction of the energy originally in grain is held in human tissue if we do the following: grain eaten by
humans. we would receive 1/10th of the energy from the grain
Explain the statement: matter recycles in ecosystems. There is a Carbon cycle. Carbon is absorbed in
photosynthesis by producers and passed to consumers which releases the carbon back to the atmosphere after
they die, allowing the cycle to start over again.
Describe the following cycles: phosphorus, nitrogen, carbon/oxygen, water.
a)
Phosphorus cycle:
i)
phosphorus within sediments are brought to the surface by uplift or volcanic activity
ii)
the phosphates within rocks break up and become soil over time
iii)
phosphates in the soil then either cycle through plants animals and detritivores, or it gets washed
into water where it will either cycle through plants and animals or sink back into the earths
sediments.
b)
Nitrogen cycle:
i)
Atmospheric Nitrogen can enter the soil via lightning or nitrogen fixing bacteria, or enter plants
via nitrogen fixing bacteria within the plants.
carbon dioxid
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water
solar energy
glucose
oxygen
ii)
c)
d)
See the picture (describing it would be too confusing)
Phosphorus Cycle
Nitrogen Cycle
Carbon / Oxygen cycle:
i)
CO2 in the air and water is taken in by plants via photosynthesis, with a byproduct of Oxygen
released into the atmosphere.
ii)
The carbon in plant tissue is either transferred to animal tissue, or the sediments after they die.
iii)
The atmospheric oxygen is used by animals and release CO2 into the atmosphere as a byproduct
iv)
The carbon in the sediments become fossil fuels which release the carbon into the atmosphere
after combustion
Water cycle:
i)
Water evaporates and forms clouds. The clouds precipitate in the form of rain, fog or snow etc.
The water flows from the land to bodies of water such as lakes rivers or oceans. Some water goes
down into the sediments to become ground water
Carbon / Oxygen Cycle
Water Cycle
109.
Describe how the following are related: succession, pioneer species, equilibrium species, seral species, climax
species, primary succession, secondary succession, allogenic succession, autogenic succession.
a)
Succession – a directional, cumulative change in species in a given area thru time. Succession typically
begins on soil or rock. There are two major causes to succession;
i)
Allogenic changes – due to major environmental changes (fire, geo uplift, volcanism)
ii)
Autogenic changes – created by inhabitants of the community
b)
Pioneer species – usually plants or lichens begin succession by growing on soil or rock. The break
down rock into soil, grasses will hold the soil and form extensive root systems. r selected
i)
Equilibrium species – aka seral species. This replaces the pioneer species as soil accumulates.
c)
d)
110.
Equilibrium (seral) species include perennial shrubs, or forests which may be replaced by trees over time.
This is a transitional group with will give way to climax species
a)
Climax species – replaces the equilibrium (seral) species. Considered the dominant species in
the mature ecosystem and tend to maintain themselves. k selected
Primary succession – begins on bare rock. Primary succession takes place after a volcanic or glaciation event
Secondary succession – begins on soil. Described as a reversion of succession to a previous state.
How do the following change between early and late succession: nutrient storage, biomass, species diversity,
stability, species reproduction and longevity.
Characteristic
Early succession
Late succession
Nutrient
In soil
In biomass
Biomass
low
high
Species diversity
low
high
Stability
low
high
Species
r-selected (short lived, fast reproducer)
k-selected (long lived, slow reproducer)
111. What is a trophic cascade, and what initiates one? A trophic cascade is a domino effect on the food web. These
are caused by the introduction or removal of a species from an ecosystem. Example: the reintroduction of the
wolf to Yellowstone has had good affects. The introduction of the Cane toad to northern Australia has been
devastating to the native fauna
112. What are keystone species? Keystone species are organisms that are pivotal or crucial to establishment of, and
maintenance, of a particular ecosystem.
113. What factors influence the cycling of prey populations? 3 factors affect prey populations
a)
Climate and food availability
b)
Prey density, which affects social behaviors and litter size
c)
Predator density
114. Why are predators and prey considered coadapted? Predators and prey have a big impact on the genetic
integrity of one another. Predators eliminate sick, weak and poorly adapted individuals. Prey in-turn influences
the quality of the predator populations if they can avoid predation. As a result predators and prey evolve
together in a constant arms race to out-do each other and are said to be co-adapted
115. Why are hunters a poor substitute for natural predators, and why do ecosystem managers try to reintroduce
natural predators? Unlike natural predators, hunters kill the healthiest animals in the prime of their reproductive
years and eliminate a lot of the well adapted genes from the gene pool.
116. Describe and give examples of the following: positive feedback, negative feedback, positive synergism,
negative synergism, biological magnification, and threshold concentrations.
a)
Positive feedback – occurs when a stimulus causes a response that increases the stimulus. Example
would include the Bison who kill trees by rubbing their horns on them, resulting in more grassy pastures
for the bison to feed from which results in more bison. Disrupts stability
b)
Negative feedback – occurs when a stimulus causes a response that inhibits the stimulus. Example
would include a leak in a beaver dam which stimulates a beaver to repair the leak stopping the stimulus.
Maintains stability
c)
Positive synergism – occurs when the combined effects of two stimuli is greater than expected 2+2=5
d)
Negative synergism – occurs when the combined effects of two stimuli is less than expected 2+2=1
e)
Biological magnification - is the increase in concentration of a substance, such as the pesticide DDT,
that occurs in a food chain. Occurs with fat soluble toxins and usually affects higher order predators
f)
Threshold concentrations – the concentration level at which the toxin affects the health of the animal.
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How has increased human population put pressure on ecosystems? Many ways
a)
Need cropland – deforestation; run off from crop land pollutes rivers, streams, and lakes
b)
Pollution – a growing human population brings more and more pollution or air water and soil
c)
Energy needs – mining for fossil fuels destroys habitat, burning fossil fuels pollutes the air
d)
Housing – leads to deforestation, loss of habitat
e)
Water needs – less water for habitats
f)
Hunting / poaching
g)
Introduction of non-native species – can cause a trophic cascade
h)
Road building – hazardous for wildlife – road kill
Describe the difference between threatened and endangered species.
a)
Threatened species – still abundant over range, but numbers declining at a rate to make them
endangered in a short period of time
b)
Endangered species – so few individuals that they are likely to become extinct over all or part of range
What are some characteristics that put species at risk of becoming extinct, and how many of these must a
species have to be considered “at risk” of extinction? Must have two of the following to be considered “at risk”
a)
Feed at a high trophic level – predator
b)
Large size – needs to consume large quantities of energy
c)
Low reproductive rate
d)
Limited or specialized breeding/nesting grounds – many sea birds nest on one or two islands
e)
Specialized feeding habits – black footed ferrets feed only on prairie dogs
f)
Unhealthy behaviors –
g)
Intolerance of humans – grizzly, condor
h)
Preys on livestock – wolf, grizzly
i)
Valuable fur or other parts, rhino horn, eagle feet
j)
Found in only one place – Galapagos animals
What is the greatest cause of extinction worldwide? loss of habitat is considered the major cause of extinction
Of what value is wildlife according to the Endangered Species Act? Aesthetic, ecological, educational,
historical, recreational, and scientific value to the nation and its people.
What agency has primary jurisdiction over regulation of endangered species? Fish and Wildlife Service
How does the Endangered Species Act define “critical habitat” and why is it so important to the success of the
Act? Includes areas needed for breeding, and cover and shelter to maintain normal population growth and
behavior. It also protects migratory routes for these species
Why do biologists consider the Endangered Species Act a tremendous success? Because animals that were
listed as endangered 30 years ago are still alive regardless if their still on the list or not.
Describe albedo and emissivity.
a)
Albedo – is a measure of the energy reflected by clouds and dust in the upper atmosphere. Albedo is
about 1/3 of the energy reaching the earth
i)
Albedo increases the earth cools
ii)
Albedo decreases the earth warms
b)
Emissivity – is the rate at which energy is irradiated back into space
i)
Emissivity decreases the earth warms
ii)
Emissivity increases the earth cools
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What is greenhouse warming and what is its cause? Greenhouse warming is when energy enters our atmosphere
which alters the wavelength preventing irradiation back into space causing a decrease in emissivity. It’s caused
by an increase in carbon dioxide in the atmosphere.
What are potential dangers of global warming? Lots of dangers
a)
Modification of the world’s climates, melting of polar ice caps, potential for tropical vectors to
temperate regions, possible effect on food supply, forest fires may increase, many effects are unknown
What are common greenhouse gases? Include: carbon dioxide, methane, and water vapor
What are possible effects of global cooling? Effects would include: the opposite of warming. Growing belts
would probably shift towards the equator, etc. an ice age, or mini-ice age could conceivably occur
Why be concerned about global temperature changes? Climate change accounts for mass extinctions in the
fossil record. We are warming 1000 times faster than an time in the last 430,000 years.
What is ozone and why is it important? Ozone is O3. It’s a gas that absorbs UV radiation, and is protective to
life on earth.
What are common ozone depleting gases?
a)
Chlorofluorocarbons (CFC’s) – used as refrigerants, foam blowers, aerosols
b)
Halon – bromine containing chemicals which are 10x more damaging than CFC’s. used in fire
extinguishers
c)
Carbon tetrachloride – an industrial solvent
How does ozone depletion occur? It requires cold temperatures to occur. In the Antarctic winter, ice crystals
form in the upper atmosphere. These crystals produce surface area onto which CFC’s condense and concentrate.
The CFC’s react with UV radiation to release Chlorine, a very reactive element which does react with the ozone
Why be concerned about ozone depletion? For each 1% decrease in ozone, there is an increase in UV radiation
by more than 1%. UV is the leading cause for skin cancer. UV alters DNA. Plants and animals are suffering
from ozone depletion. Amphibians are disappearing all over the world. Plant productivity is reduced
What evidence is there for both greenhouse warming, and ozone depletion? Plant production down, amphibians
dying out
Why is food more scarce, even though food production increases worldwide each year? Because the human
population is growing exponentially
What is the major cause of hunger and malnutrition? Poverty. There is still enough food to feed the world, but
many are still malnourished.
Why is depletion of energy resources a threat to humanity? Fossil fuels are finite (will run out someday). Many
fossil fuels like the abundant coal will cause massive habitat destruction when mining and burning
What kinds of problems are we experiencing with our water resources? Ground water is being depleted, and is a
major source of agricultural water
a)
Overgrazing leads to loss of groundwater
b)
Groundwater takes a long time to regenerate
Groundwater is routinely polluted in urban and rural environments.
What are some major water pollutants?
a)
Oxygen demanding wastes – sewage, manure industrial wastes (decomposer populations explode)
b)
Disease causing agents – bacteria, viruses, other parasites
c)
Inorganic chemicals and minerals – acids, salts, toxic metals
d)
Synthetic organic chemicals – pesticides, herbicides, plastics, detergents
e)
Plant nutrients, nitrates, phosphates
f)
Sediments, sand silt, clay, SOC’s and nutrients washed from soil
g)
Radioactive substances
h)
Heat – from power plants
Why be concerned about radioactive waste disposal? Radioactive isotopes can be dangerous for hundreds of
millions of years. Where do you store them for that long? May lead to groundwater contamination.