Biology 1112
Lecture Three
Slide 2 – Common terms and definitions - sporangium
Sporangium (sporangia) – is
an organ containing and/or
producing spores.
It is also defined as a
protective layer of sterile
cells surrounding haploid
spores in a sporophyte
(defined as a spore-case or
a receptacle for spores).
Slide 3 – Common terms and definitions – Sporophyte and gametophyte
•
Spore (zoospore) – an asexual reproductive cell that can develop into a
free living organism
•
Sporophyte – Diploid structure and is a spore producing stage of protests
and/or some plant life cycle with each cell containing two complete sets
of chromosomes
– It is also defined as the spore-producing individual or phase in the
life cycle of a plant having alternation of generations
– The sporophyte develops from the union of two gametes, such as an
egg fertilized by a sperm; in turn, the sporophyte forms spores that
develop into gametophytes.
•
Gametophyte – haploid, multicelled, gamete producing phase in life cycle
of most plants.
– Gametophyte is a phase of an organism’s life cycles in which the
gametes (e.g. egg and sperm) are produced.
– The gametophyte is haploid, that is, each cell contains a single
complete set of chromosomes, and arises from the germination of a
haploid spore.
Slide 4 – Common terms and definitions – hyphae and mycelium
Hypha (hyphae) – is
composed of fine
microfilaments usually
consists of chitin. These
structures are usually
involved in absorption
structure component of the
mycelium
Mycelium – A multicellular
structure that is formed by
a mesh of branching
hyphae
Slide 5 – Kingdom Protista
Slide 6 – General characteristics of protists
• Most organisms that belong to
the Kingdom of Protista (or
protests) are generally
unicellular organism.
• Protists are eukaryotes and
have a nuclear envelope
encircling their genetic
materials.
• These eukaryotes have
membrane bounded organelles
within their cytoplasm.
• Protists have plant-like, fungallike, and at times animal-like
characteristics
• Some scientists believe they are
the protists evolved into higher
organisms.
Paramecium
Slide 7 – Protists’ characteristics (movement)
Mobility – most protists utilizes either flagella, cilia,
amoeboid-like (using pseudopods) for movement
Slide 8 – Protist characteristics (energy production/consumption)
• Food or energy production – protists could either utilize
chloroplasts (autotrophic) for energy production, taking in
(ingesting) organic substance via food vacuoles (heterotrophic),
or possesses both the combined ability
Slide 9 – Protist characteristics (reproduction)
•
Reproduction – they could reproduce
either asexually or sexually. Sexual
reproduction generally occurs when
conditions are harsh and that genetic
diversity may aid in the organism’s
ability to survive
•
Survival – when faced with harsh
conditions, the protists develops
many sporangia where spores are
produced and released to propagate
in many different locations where one
of these locations may allow the
‘offspring’ of the protist to survive
• Furthermore, protists may
also survive the onset of
harsh environments by
forming cysts
• A cyst is a dormant cell with
a resistant outer covering,
which allows it to survive
harsh droughts, temperature
changes and even digestive
juices of the animal digestive
tracts.
Slide10 – Importance of protists
•
Some protists belong to a group of freefloating organisms know as planktons are
photosynthesizes and they gives off oxygen
•
These planktons provide food for other
heterotrophic protists and animals
•
Protists also form symbiotic relationships
with corals and allow the corals to become
photosynthetic
•
A type of protists known as algae can
provide valuable materials (e.g. agar) for
medical or scientific research. Algae can
processed to form fertilizers and can be
harvested for algin – a pectin like substance
that is added to ice cream, cheese to give it
stable consistency
•
Diatoms – a type of protist with its silicate
based outer shell will accumulate on the
bottom of the ocean. These diatoms are
harvested and used as filtering agents,
sound proofing materials and gentle
abrasives
Slide 11 – Chytridiomycota
Chytrids (chytridiomycota) – chytrids
are molds that predominantly exists in
both marine and fresh water
environments
Most of these organisms are saprobes
– a type of heterotrophs that secrete
digestive enzymes to break down
organic substances in its immediate
surroundings. Once the organic
substance is broken down, chytrids
than absorb the nutrients
Some Chytrids are parasites on living
plants and animals (e.g. mosquito
larvae, nematodes and liver flukes)
Most of the chytrids are also known as
decomposers which are responsible
(generally) for breaking down dead
materials
Chytrids have chitin strengthening their
cell walls, and one subgroup
(Hyphochytrids) have cellulose as well
Slide 12 – Chytridiomycota lifecycle of Allomyces – alternation of isomorphic generations
Slide 13 – Water molds (Oomycota)
Oomycota are saprobic decomposers
that reside mostly in moist and/or
aquatic habitats
Oomycota are previously grouped
into Kingdom Fungi but now are
placed in protests
There are about 475 species of
Oomycota
Oomycota are commonly referred to
as Oomycetes
Some oomycota are parasitic (e.g.
blight of potatoes – Irish potato
famine in 1845-1847)
They produce extensive mycelium
and contain cellulose in their cell wall
rather than chitin
They can reproduce sexually and
asexually
Slide 14 – Lifecycle of Oomycota (Saprolegnia ) - alternation of heteromorphic generations
Slide 15 – Cellular slime molds (Acrasiomycota)
Cellular slime molds (Acasiomycota) spend most of their lives as separate
single-celled amoeboid protests
Cellular slime molds consists about
65 species
These free living amoeba like cells are
phagocytic predators and feed off
bacteria or decomposers who feeds
off decaying leaves or bark
These amoeba like cells are haploid
(n) containing a single nucleus
These organisms are similar to plants
where they are rich in cellulose
Slide 16 – Reproductive cycle of cellular Slime Mold (Dictyostelium discoideum)
Slide 17 – Plasmodial slime molds
Plasmodial slime molds (Myxomycota) are
composed of many single celled slime molds
with no cellular boundaries which gives it the
appearance of having thousands of nuclei
Plamsmodial slime molds consist of 450 species
They are formed when individual amoeboid like
cells swarm together and fuse
There are no boundaries between the individual
amoeboid-like cells therefore they are referred to
as multinucleate plasmodium
The result is one large bag of cytoplasm with
many nuclei with free floating cytoplasm also
known as cytoplasmic streaming
These plasmodial slime molds are both
predatory as well as decomposers where they
ingest bacteria, fungal spores and dead leaves
etc.
The plasmodial slime molds reproduce both
sexually and asexually
Slide 18 – Reproductive cycle of plasmodial slime molds
Slide 19 – Binary fission - protozoan
Slide 20 - Protozoan cysts (Entamoeba histolytica - amebic dysentery)
Slide 21 – Amoeba-like movement
Slide 22 – Amoeboid protozoans (Sarcodines)
Slide 23 – Rhizopods – entamoeba histolytica
Slide 24 – Paramecium trichocysts
Slide 25 - Paramecium
Slide 26 – Protozoans conjugation
Slide 27 - Giardia lamblia - Giardiasis
Slide 28 - Trichomonas vaginalis
Slide 29 – African Sleeping Sickness
Slide 30 – Pneumoncystis carinii
Slide 31 – Malaria – plasmodium vivax
Slide 32 – General symptoms of Malaria
Common symptoms
1
Fever
2
Flu-like symptoms
3
Chills
4
Severe headaches
5
Arthralgia
6
Jaundice
7
Anemia
8
Vomiting
9
Convulsions
10
Bloody urine
11
Hepatomegaly
12
Spenomegaly
13
Coma
14
Death
Matured trophozoite and ruptured schizont in red blood cells
Slide 33 – Single cell algae - diatoms
Slide 34 – Multi-celled algae
Slide 35 – Zoospores – flagellated spores
Slide 36 – Isogamous – gametes of the same size and shape
Slide 37 – Oogamous – Sperm and egg
Slide 38 – Alternation of generation
Alternation of
generation –
the life cycle
of the
organism is
alternating
between
haploid (1N)
and diploid
(2N).
There are two
types of
alternation
of
generations:
Slide 39 – Haplontic and Diplontic reproductive cycle
Haplontic
reproductive
cycle – the adult
is haploid (1N)
Diplontic
reproductive
cycle – the
adult is diploid
(2N)
Slide 41 – Diatoms – phytoplankton
Slide 42 - Diatoms
•
They are important part of the food source for both fresh water and marine
organisms
•
The diatom is composed of a box like structure where it is arranged in a two half
structural system – a larger top half and a smaller lower half
•
Outside of the cell wall of the diatom is a silicate compound similar to glass and are
used for protection
•
Diatoms lack flagella and are free-floating organisms
•
Asexual reproduction – where the asexually reproduced half receives the top half of
the “box” while the new “box” grows inside of the old one
-
•
Because of the box within a box system of asexual reproduction, the new
organisms are 30% smaller on average than the original.
Sexual reproduction – (haplontic) diatoms produces oogamy (sperm and egg) while
the sperm are flagellated
-
The zygote (2n) grows and divides mitotically and produces diatoms of normal
size
•
Commercial benefits – The remains of diatoms with its silicate based outer shell will
accumulate on the bottom of the ocean.
•
This is harvested and is used as filtering agents, sound proofing materials and
gentle abrasives
Slide 43 - Dinoflagellates
Slide 44 - Dinoflagellates
•
If the cell wall is present, they are mostly composed of cellulose plates
•
This type of organism possesses two flagella for mobility
•
They contain both chlorophyll a and c and are also a part of the phytoplankton population
within earth’s oceans
•
Reproduction – Dinoflagellates proceed through mitosis (asexual reproduction a form of
binary fission) nevertheless they have some significant differences in their process of
mitosis
•
The nuclei of the dinoflagellates are unlike those of any other organisms – the
chromosomes lack any centromere and are permanently in condensed formation
•
Even when the organism is proceeding through mitosis, the nucleolus and nucleus persist
throughout cellular division
•
Benefits – some dinoflagellates forms symbiotic relationships with corals and allow corals
to become photosynthetic
•
Commercial significance – Some dinoflagellates when their population increases may
cause “red tide”
• These dinoflagellate produces a type of neurotoxin that causes paralysis in fish
and could be accumulated in shellfish
• These shellfish, if consumed by humans, will cause paralysis of the respiratory
tract and eventually death
Slide 44 – Red Tide
Slide 45 - Euglenoids
Slide 46 - Euglenoids
– One-third of this group is photosynthetic (photoautotrophs) while
the remaining are heterotrophs (ingesting or absorb organic
materials for food).
– They contain two flagella where one is longer than the other
– They have a pyrenoid – which is centers of carbon dioxide
fixation
– Through carbon dioxide fixation they produces a type of
carbohydrate known as paramylon for storage and utilization
– They have chloroplasts containing chlorophylls a and b and
various carotinoids
– Euglenoids also have an eyespot, which contains photoreceptors
for detecting light.
– Reproduction – mitosis (asexual) in a form called longitudinal cell
division
Slide 47 – Green algae - chlorophyta
Slide 48 - Chlorophyta
– This unicellular organism and/or multicellular organism comprise
of 8000 different species
– They live in oceans, fresh water or even on land where
abundance of moisture is available.
– Green algae form symbiotic relationship with fungi, plants and
even animals.
– They are believed to be closely related to plants since they
possess cell walls that contain cellulose and have chlorophyll a
and b and stores starch inside the chloroplast, which is similar to
that of plants.
– These organisms release oxygen as a by-product just like plants
– Sexual reproduction – Haplontic cycle
Slide 49 – Flagellated green algae
This type of protist has a
definite cell wall and a
large cup-shaped
chloroplast that contain a
pyrenoid (where starch is
synthesized)
This algae also contain a
stigma or eye spot to
identify where the light
source are located and
direct the two whip-like
flagella towards the light
source
Sexual reproduction –
Haplontic cycle
Pyrenoid
Slide 50 – Filamentous green algae
Slide 51 - Spiralgyra
These haploid organisms are found in pond surfaces
and streams
These algae contain a ribbon like spiral chloroplast.
Asexual reproduction - when conditions are
favorable they produce asexually forming zoospores
(flagellated spores - isogametes) that are similar to
the parent cell
These spores are haploid (1n) and develop
into a mature adult
Conjugation - Sexual reproduction –– occurs during
winter and harsh conditions
- Temporary union that occurs
between two cells align each other
parallel to one another and forming a
temporary connection
- The entire content of one cell is
subsequently transferred from one
cell to another forming a diploid
organism or a zygote
- After the favorable conditions returns
the cell undergoes meiosis and
produces four new haploid
organisms
Oogamy - sexual reproduction – When conditions are
unfavorable, the algae produces an egg and a motile
sperm for this form of sexual reproduction
Slide 52 – Multicellular green algae - ulva
Slide 53 – Colonial Green Algae
Commonly known as a volvox – these are
a loose connection of independent cells
that resulted in the formation of a colony.
The cells within this colony are
specialized in their functions
Some cells are for sexual reproduction
only while others are for mobility by
coordinating their flagella in a
unidirectional manner
The Volvox’s appearance is that of a
hollow ball and can proceed in asexual
and sexual (oogamy) reproduction
During asexual reproduction a smaller
daughter colony is formed within the
hollow space within the Volvox, which
later escapes the parent cell by dissolving
away a portion of the parental colony.
Sexual reproduction – a slight variation of
Haplontic cycle
Slide 54 – Red algae
Slide 55 – Red algae
– A type of marine seaweeds – Known to grow in warmer of
tropical seawaters
– Some red algae are simple filaments while others are
complexly branched having feathery or leafy appearance.
– They contain cellulose and calcium carbonate within their cell
walls and have both chlorophyll a and chlorophyll d (not seen
in plants)
– They reserve their food source in a form of sugar that
resembles glycogen (animal sugar), which is in turn called
floridean starch
– Sexual reproduction – their reproductive cycle are still mostly a
mystery nevertheless, they do have an oogamy generation
which sperm and egg are produced
• The sperm of red algae are non-flagellated and are unique
in this manner
– Commercial benefits – they produce agar for scientific usage
Slide 56 – Brown algae
Slide 57 – Brown algae
– Another type of marine seaweeds – more temperate to cold
seas (California coast etc.)
– This type of algae has chlorophyll a and chlorophyll c in
their chloroplasts and a type of carotinoid called
fucoxanthin.
– Their reserve food source is in the form laminarin (a type of
sugar)
– These algae are resistant to dry out usually since their cells
wall contain a mucilaginous, water retaining material
– Sexual reproduction – Diplontic cycle
– Commercial benefits – they can produce fertilizers and can
be harvested for algin – a pectin like substance that is
added to ice cream, cheese to give it stable consistency
Slide 2 - Fungi
Slide 3 – General characteristics of fungi
Fungi have the following characteristics:
•
They are eukaryotic organisms
•
Most are multicellular eukaryotic organisms
•
Some are unicellular organisms – yeast is the prime example
•
They are heterotrophs that consume organic matter
•
They do not consume their food source but they absorb nutrients
– Fungus spew out digestive enzymes and dissolve the organic matter
externally and then they absorb the food source
•
Most fungi are saprotrophic that decomposes organic matters such as
leaves or dead bodies
•
Some fungi are parasitic
•
Some fungi form mutualistic relationship with roots of seed plants where
they acquire inorganic nutrients for plants and in return they are fed
organic matters by the plant itself
Slide 4 – Mycelium and hyphae of the fungi
Mycelium
Hyphae
Slide 5 – Function of hyphae
– The branching hyphae provide large surface area for the fungi
– The large surface area allows the fungi to increase its absorption
rate/amount
– The tips of the hyphae grows while the bundle of hyphae (known as
mycelium) absorbs and pass nutrients to the growing tips
– Reproduction occurs when a specific part of the mycelium becomes
a reproductive structure while the remaining mycelium provides
nutrients it needs
– Fungi cells contains no chloroplasts
– Fungi cells contains a cell wall that is constructed out of chitin
(similar to the exoskeleton of a shrimp or crab) and not cellulose
– The storage sugar of the fungi is glycogen and not starch - similar
to animals
– Fungi are immobile throughout their life cycles (no flagellated
sperm etc.)
Slide 6 – Septae and nonseptate fungi
Septa
Septae fungi
Nonseptae fungi
Slide 7 – Fungi – sexual reproduction
Slide 8 – dikaryotic – sexual reproduction of fungi (n + n)
Slide 9 – zygospore fungi
Characteristics of a zygospore fungi (bread mold):
- A horizontal hyphae called a stolon exist
on the surface of the bread and eventually
grows into the bread itself.
- Mycelium forms through aggregation of
hyphae while rhizoids grows out and
anchors the mycelium
- Mycelium carries out external digestion
and food absorption
- During asexual reproduction a
sporangiophore grows out of the
mycelium and at the tip of this structure
a sporangium is formed.
- Sporangium produces haploid spores
and are subsequently released into the
environment
Slide 10 – sac fungi - truffles
Sac Fungi – (~30,000 species)
they are saprotrophs that
digests materials that are
otherwise not easily digested
(e.g. cellulose, lignin or
collagen etc.)
- Truffles belong to
this group of fungi
- Yeast is another
example but it is an
unicellular sac fungi
Slide 11 – club fungi – common mushrooms
Ergot on wheat
Slide 12 – imperfect fungi - Penicillin notatum
Slide 13 – Magic mushrooms
Slide 14 – deadly mushrooms – Destroying Angel
The structure of alpha-amanitin
Slide 15 – Origin of fossil fuel
Slide 16 – Plant cuticle
Slide 17 – Stomata (stomates)
Slide 18 – Carotinoids (e.g. ß - Carotene)
Slide 19 – Plant sex organs (gametangia)
Slide 20 – Sporophyte and gametophyte generations of plants
Slide 21 – vascular vs. nonvascular plants
Slide 22 – Characteristics of nonvascular plants
Non-vascular plants has
the following
characteristics:
• Gametophyte is the
dominant generation in
non-vascular plants
• The flagellated sperm
swim to the egg (located
in the archegonia) in a
water fill medium
• Due to the flagellated
sperm, the non-vascular
plants usually require a
moist environment.
Slide 23 - Bryophytes
Bryophytes (non-vascular plants) are mosses,
liverworts and hornworts
• They do not have internal vascular structures such
as xylem or phloem to transport water and nutrients
(dissolved sugars and ions) respectively
• They do have leafy and stem like structures that
makes up their body
• Bryophytes are capable of being dried out (proceed
in a form of dormancy) and still revive itself after the
absorption of water
• They have rhizoids that are very similar to roots but
again do not have internal vascular structures
nevertheless performs anchoring and absorption
duties
Slide 24 – Non-vascular plants - hornworts
Hornworts – are usually
found in tropical forests,
along streams, and in
disturbed fields around
the world
Most species are small
and unassuming greasy
blue-green patches
Hornworts will generally
have a single large
chloroplast per cell.
Slide 25 – non-vascular plants - liverworts
Liverworts – all liverworts has the following traits:
A flattened thallus or a leafy body or a lobed
thallus or body
Each thallus has a smooth upper surface and a
lower surface that possesses numerous rhizoids
– hair or root like projections into the soil.
Liverworts are capable of sexual and asexual
reproduction
Sexual reproduction depends on the disk-headed
stalks that bear antheridia – where the flagellated
sperm are produced.
Eggs are produced on the umbrella-headed stalks
that bears the archegonia.
After fertilization a tiny sporophyte composed of
a foot, short stalk and capsule appears.
Windblown spores are produced within the
capsule
Slide 26 – non-vascular plants - mosses
Mosses – Mosses can be found from the Artic
through the Antarctic although they prefer damp
temperate environments. Mosses have the
following traits:
Mosses have usually a leafy shoot
Mosses can contain a tremendous amount of
water and can become dormant when the
environment becomes too dry
Mosses can reproduce asexually by fragmentation
– just about any part of the plant can produce leafy
shoots
This form of reproduction is most common in
desert, artic and Antarctic regions
Mosses have Rhizoids those functions as an
anchor. Rhizoids also contain the antheridia and
archegonia
The antheridia consist of a short stalk, an outer
layer of non-reproductive cells used for protection
and an inner mass of cells that becomes the
flagellated sperm
Slide 27 – Vascular plants
Slide 28 – vascular plants
Slide 29 – Anatomy of roots
Slide 30 – Anatomy of a plant stem
Slide 31 – Anatomy of a vascular leaf
Slide 32 – Microgametophyte (e.g. pollen)
Slide 33 - Megagametophyte
Slide 34 - horsetail
Slide 35 – Whisk fern
Slide 36 – Ferns – fiddle head and fronds
Slide 37 – Lifecycle of ferns
Slide 38 – Gymnosperm lifecycle
Slide 39 – conifers - Redwood (Sequoia sempervirens)
Slide 40 - cycads
Slide 41 – Ginkgo trees
Slide 42 - Gnetophytes
Slide 43 - Dicot stems
Slide 44 – monocot stems
Slide 45 – Lifecycle of an Angiosperm
Slide 46 – Anatomy of a flower