Plants and Animals: Flashcard Review (2011-12)
1. Describe an example of a structure-function relationship at the cellular level in plants.
When some cells (such as epidermal cells) are first formed, they have extensions known as root hairs.
The root hairs of a plant branches thousands of times to increase surface area. These root hairs can uptake
nutrients, water, and minerals from the soil. Root hairs are only found in the zone of maturation, not the zone
of elongation, because any root hairs that arise are sheared off as the root elongates and moves through the
soil. This large surface area structure of the plant cells fit well with their function.
2. Describe an example of a structure-function relationship at the organ level in animals.
The structure of cardiac muscle fits the function of cardiac muscle in the heart. Cardiac muscle is able
to contract at a steady rate until the human dies because of its ability to auto-regulate its own contractions, its
specific mechanism of utilizing calcium, and its internal cellular structure of cross-linking actin and myosin as
well as individual fiber orientation relative to the others. Therefore, cardiac muscle will never fatigue, unlike
skeletal muscle which contracts forcefully and quickly due to its high metabolic demands. The structure of the
organ allows this lack of fatigue of the heart.
3. Regulation: Describe and diagram the regulation of blood sugar.
In the liver, glycogen is broken down into glucose, which is released into the blood. The sympathetic nervous
system speeds up the breakdown of glycogen, while the parasympathetic nervous system facilitates the
synthesis and storage of glycogen. The pancreas secretes insulin and glucagon. Insulin lowers blood sugar
levers, while glucagon raises these levels.
4. Neurulation
Neurulation is the process by which the neural tube and neural crests are formed. First, the ectoderm thickens
and becomes a neural plate. The plate starts to fold and rise as cells change shape and adhesion between cells
changes. The edges of the plate meet in the middle and form a tube. The cells at the tips of the neural folds
become neural crest cells, which lie between the neural tube and the epidermis and can give rise to a variety
of cell types. The neural tube gives rise to the spinal cord and brain. The notochord induces neural plate
formation.
5. Describe a countercurrent exchange system and explain its adaptive advantage.
Fish breathe using a counter current exchange system. The blood in the capillaries flows in the opposite
direction from the water in the adjacent channels. Dissolved gases diffuse faster between fluids with a large
difference in gas concentration (a high concentration gradient) than between fluids with only a small
difference.
6. Describe an adaptation that increases surface area in an animal system. Explain how this improves
the function of the system.
The small intestines have a "finger" like structures on the walls (villi). This creates more surface area so more
food can be digested.
7. Describe an example of a structure-function relationship at the tissue level in plants
The trichomes are tinny hair like extensions, with a large surface area and minimal volume, on the
stem, leaves and reproductive organs. They help trap water in the air creating a layer of humidity around the
plant. This keeps the plant cool and slows down evaporation allowing the pant to receive the maxium benefits
from the water in the air.
8. Discuss how the structure of a protein affects muscle contractions
The functional unit of the muscle is the saromere made up of the thin actin filaments and thick
myosin filaments. At the beginning of a contraction Ca+ ions bind to the troponin shifting the protein and
exposing myosin binding sights. ATP binds to the myosin causing the cross bridges to extend and pull the
action towards the center of the sarcomere. The ATP then degrades into ADP and P causing the bridges to
release and the muscle to relax
9. Explain how T cells protect vertebrates from invasion by pathogens. T cells binds to a peptide-MHC
complex on the cell surface and also receives stimulatory signals suggesting parasite invasion. The T
cell can trigger the death of the infected cell. T cells bind to parasite peptides digested in infected cells,
helping to clear intracellular infections.
10. . Gastrulation- a phase in embryonic development where the blastula becomes a three-layered
gastrula. The three layers include the ectoderm, endoderm, and mesoderm.
11. Describe an example of a structure-function relationship at the tissue
level in animals.
-The tissue in the lungs has a large surface area for absorption
because of the alveoli in the lungs that increase it. This structure
reflects the function of the lung tissue of oxygen intake because by
increasing surface area, the lungs maximize the amount of oxygen taken
into the blood.
12. Explain how B cells protect vertebrates from invasion by pathogens.
-B cells protect vertebrates by producing antigens to combat
pathogens, act as APCs, and become the memory type in order to
effectively combat the same pathogen in the future.
13. Describe and diagram the regulation of metabolism by thyroxine:
Thyroxine, or T4, is a thyroid hormone secreted by the thyroid gland. Too much or too little thyroid hormone
leads to serious metabolic disorders, for example, excessive secretion of the hormone can lead to Graves'
disease. In Graves' disease, the immune system produces antibodies that bind to the receptor for TSH and
activate sustained thyroid hormone production. An effect of too little thyroid function can lead to
hypothyroidism and produce symptoms such as weight gain and lethargy.
14. Polar Nuclei - The two haploid nuclei found in the centre of the embryo sac after division of the
megaspore. They may fuse to form a diploid definitive nucleus before fusing with the male gamete to
form the triploid primary endosperm nucleus.
15. Describe an example of a structure function relationship at the organ level in animals
One example of structure function relationship in animals is the structure of the heart and its function. The heart
is made up of four chambers: two atria and two ventricles. Between the atrium and the chamber is a one way
valve that prevents the backflow of blood into the atrium. There is also a one way valve between the ventricles
and the arteries to prevent backflow into the ventricles. This structure fits its function because the purpose of
the heart is to efficiently move blood through the body. The valves allow the heart to move blood forwards and
not backwards. The structure of the mammalian heart increases the efficiency of the heart and allows it to
function the way it was intended to function.
16. Explain the relationship between the sporophyte and gametophyte stages of a plant life cycle.
Plant life cycles involve an alternation between two generations: a haploid stage, called the "gametophyte",
and a diploid stage, called the "sporophyte".
The sporophyte is short-lived and remains dependent on its parent gametophyte. The gametophyte is the
haploid, multicellular phase of plants and algae that undergo alternation of generations, with each of its cells
containing only a single set of chromosomes. The gametophyte produces male or female gametes (or both),
by a process of cell division called mitosis. The fusion of male and female gametes produces a diploid zygote,
which develops by repeated mitotic cell divisions into a multicellular sporophyte. Because the sporophyte is
the product of the fusion of two haploid gametes, its cells are diploid, containing two sets of chromosomes.
The mature sporophyte produces spores by a process called meiosis, sometimes referred to as "reduction
division" because the chromosome pairs are separated once again to form single sets. The spores are
therefore once again haploid and develop into a haploid gametophyte.
17. Describe how a hydrophobic hormone, like sex hormones, triggers the response of a target cell.
The endocrine system is a complex communication network made up of specialized cells, glands and
hormones. The glands release hormones into the blood or the fluid surrounding cells in response to stimuli
from inside and outside the body. Once released, hormones travel throughout the body looking for target cells
that contain matching receptors. The hormone binds with the receptor, something like how a key fits a lock to
unlock a door. Hormones need to have a compatible receptor in order to work. The protein receptor,
depending on the type of hormone and its specific message, carries out the messenger's instructions by either
altering the cell's existing proteins or turning on genes that will build a new protein. Both actions create a wide
array of body responses. For instance, sex hormones seek out specific target cells and bind to receptor
proteins located inside the nucleus of the cell. This lock and key binding triggers the cell's DNA to start building
certain proteins, such as another hormone or an enzyme. Each hormone-receptor unit produces different
cellular and body responses because each unit turns on distinct genes that code for a specific protein.
Different proteins, in turn, cause unique biological responses: estrogens can stimulate uterine growth and
androgens can stimulate muscle growth.
18. Mesoderm: the middle of the three cell layers of the developing embryo. It lies between the ectoderm
and the endoderm. Bone, connective tissue, muscle, blood, vascular and lymphatic tissue, and the
pleurae of the pericardium and peritoneum are all derived from the mesoderm.
19. Explain how the innate immune system protects animals from invasive pathogens:
The innate immune system, also known as non-specific immune system and first line of defense, comprises
the cells and mechanisms that defend the host from infection by other organisms in a non-specific manner.
This means that the cells of the innate system recognize and respond to pathogens in a generic way, but unlike
the adaptive immune system, it does not confer long-lasting or protective immunity to the host. Innate
immune systems provide immediate defense against infection, and are found in all classes of plant and animal
life. They consist of...
• phagocytic cells: leukocytes such as neutrophils, eosinophils, and monocytes; tissue phagocytic cells in the
tissue such as macrophages
• cells that release inflammatory mediators: inflammatory cells in the tissue such as macrophages and mast
cells leukocytes such as basophils and eosinophils
• natural killer cells
• molecules such as complement proteins, acute phase proteins, and cytokines
AND...Physical Barriers.
• Skin Ex. Sweat
• Gastrointestinal tract Ex. Peristalsis, gastric acid, bile acids, digestive enzyme
• Respiratory airways and lungs Ex. Mucus, saliva
• Eyes Ex. Tears
20. Eudicot- A eudicot is an angiosperm having two cotyledons (leaf of the embryo) in the seed and flower
parts in multiples of four or five. The leaves have a network of veins radiating from a central main vein
they have a ring of cambium in the stem. Eudicots are the largest angiosperm group (they include
cultivated plants and many trees).
21. Describe the regulation of plant growth by a plant hormone:
Plant hormones are signal molecules produced in plants and they occur in low concentrations. These
hormones determine the formation of flowers, leaves, stems, and fruit. They also shape the plant, affect seed
growth, and the sex of the flowers as well as the plant longetivity and plant death. Since plants lack glands that
produce and secrete hormones, each cell is capable of producing hormones. The five major classes of plant
hormones are abscisic acid, auxins, cytokinins, ethylene, and gibberellins. Abscisic acid plays a role in leaf and
seed dormancy by inhibiting growth. Without this acid, seeds would start to grow during the warmer periods
in the winter, then the plant would die when it froze again. Auxins influence cell enlargement, bud formation
and root initiation. They also function in conjuction with cytokinins and control growth of stems, roots, fruits,
and flowers. Cytokinins are group of chemicals that influence cell divisions and shoot formation. They also
function in the delay of aging of tissues, and are responsible of auxin transport through the plant and leaf
growth. Ethylene is a gas that affects cell growth and shape. For example, when a root hits something in the
ground, ethylene production increases, preventing cell elongation and causes the stem to swell. Gibberellins
function in seed germination and affect enzyme production that mobilizes food production. The absorption of
water by the seed causes production of gibberellins.
22. Describe and diagram the human female reproductive system.
The human female reproductive system is divided into two main parts: the uterus, where the fetus develops,
and the ovaries, which are the female gonads. Ovaries produce eggs, which are released one at a time during
menstrual periods. The eggs travel through the fallopian tubes to the uterus and are fertilized in the oviduct.
The embryo embeds itself in the placental lining of the uterus. Below the uterus is the cervix, which dilates
during delivery and connects the uterus to the vagina. The vagina is connected to the external organs, the
labia, urethra, and clitoris, through the vulva.
23. Describe and diagram the regulation of metabolism by thyroxine.
Thyroxine, one of the main hormones secreted by the thyroid gland, stimulates oxygen consumption. Thus, by
controlling oxygen rates, thyroxine regulates metabolic rates. It increases the heart rate and ventilation rate.
24. Describe how a hydrophilic hormone like insuline triggers the response of the target cell:
The hormones enter the cytoplasm, easily penetrating the phospholipid membrane. Then, they enter
the nucleus and bind to a DNA receptor, creating mRNA via transcription. This new protein causes a
response from the target cell.
25. Mesophyll:
The photosynthetic cells that lie between the upper and lower epidermis layers of a leaf.
26. Describe the regulation of genes in bacteria through an inducible operon:
Inducible operons are normally "off" and are used to regulate the synthesis of enzymes involved in catabolic biochemical
pathways.
Like most operons, an inducible operon contains three major components. These components are located next to each
other on the bacterial chromosome.
The promoter region (shown in green above) is the site where RNA polymerase binds to initiate gene transcription
(making an mRNA copy of DNA).
The operator region (shown in yellow) is the site where the repressor protein binds to block RNA transcription.
Structural genes are transcribed into mRNA and contain information used by ribosomes to translate proteins. These
proteins are enzymes that are involved in a catabolic biochemical pathway.
An operon is "off" when the repressor protein is bound to the operator region.
This is the normal state of an inducible operon.
When the repressor protein is bound to the operator region, RNA polymerase is blocked and transcription cannot occur.
An inducible operon can be turned "on" only when the repressor protein leaves the operator region.
However, the repressor protein will not leave the operator region unless substrate is present.
When substrate is present (shown as a purple square above), it binds to the repressor protein, causing a change in its
shape.
The change in repressor protein shape causes it to leave the operator region.
Now that RNA Polymerase is NOT blocked, it can transcribe the structural genes.
The inducible operon will return to its “off” position, as the level of substrate decreases, causing the repressor protein to
return to its original shape and to bind to the operator region.
This is a really good website with visual aids!!
http://www.wisconline.com/objects/ViewObject.aspx?ID=MBY4707
27. mesoderm: the middle primary germ layer in an animal embryo; develops into the notochord, the lining of the
coelom, muscles,skeleton, gonads, kidneys, and most of the circulatory system in species that have these
structures.
28. Epidermis:
1. The dermal tissue system of non-woody plants, usually consisting of a single layer of tightly packed cells.
2.The outermost layer of cells in an animal.
29. Describe the regulation of genes in bacteria through a repressible operon:
Repressible operons are organized like inducible operons: there are structural genes under the control of a
promoter and operator, and there is a gene encoding a repressor. Repressible operons are not regulated by a
reactant in the metabolic pathway, but by the end product of the pathway.
When the repressor binds to the operator, it blocks RNA polymerase and prevents it from advancing along the
operon, and transcription does not occur. The regulation of the operon depends on regulating whether or not the
repressor binds to the operator.
30. Describe an example of a structure-function relationship at the molecular level in plants.

Close relationships at the biochemical, molecular, and structural levels are found in fructan
biosynthesizing and degrading enzymes and acid invertases.
All these enzymes are members of family 32 of the glycoside hydrolases. Plant invertases play important roles
in development. These enzymes interfere with sugar transport and sugar signalling, and thus influence
carbohydrate partitioning and determine crop quality and crop yield.
31. Endoderm
The innermost of the 3 primary germ layers in animal embryos. It lines the archenteron and gives rise to the
liver, pancreas, lungs, and lines the digestive tract.
32. Interdependence
Describe the interdependence between 2 different animal systems.
The digestive system and the circulatory system work to together to supply nutrients and energy to cells
throughout the body. The digestive system breaks food down into sugars, lipids, and proteins, which gets
absorb into the villi of the small intestines and enters the bloodstream. From there, the circulatory system will
move the blood all throughout the body to nourish all the cells.
33. T-tubules: T-tubules are the deep folds in the plasma membranes, or sarcolemma, of skeletal and
cardiac muscle cells. T- or transverse tubules are so named because they run perpendicular to the
muscle fibers. They are studded with several calcium chamber that allow for the exchange of ions
within the muscles. By this ion transfer, the muscles expand and contract. In this way, t-tubules are
the main mechanism that allows for the contraction of muscles in more complex organisms.
34. How do the respiratory and circulatory systems work together to support the biological needs of
animals? The respiratory system and the cardiovascular system work in close conjunction. As the
carrier of essential materials in the body, the circulatory system is responsible for the transfer and
exchange of essential gases like oxygen. The system serves as an intermediary between the body's
organs and the gases that are taken in through moist membranes in the respiratory systems.