Bio 1011 Animal Biology Flashcards
(100 cards)
1
Q
What are the characteristics of of an animal?
A
heterotrophic, multi-cellular, lacking a cell wall, capable of movement at some stage, has regulatory (hox) genes, reproduce and develop, obtain and transfer energy and matter, gas exchange, protection from external environment, maintenance of water and extra solutes
2
Q
What are the 4 different types of tissues?
A
- Epithelial tissue: sheets of cells that cover organs and the body, acting as a barrier to mechanical and or chemical pathogens.
- Connective tissue: sparse collection of cells throughout extracellular matrix. Generally as a web of fibres in a liquid, jelly, or solid foundation. Contains fibroblasts that secrete fibre proteins, and macrophages that engulf foreign particles. 3 kinds in many different areas.
- Muscle Tissue: responsible for almost every type of movement in the human body via the action of actin and myosin. There is cardiac, smooth, and skeletal muscle tissue.
- Nervous Tissue: receive, transmit, and process information from stimuli. Consists of neurons and glia that make up a brain (processing centre) and long extensions to collect info.
3
Q
Explain the structure of epithelial tissue in terms of polarity.
A
Epithelial tissue is polarized meaning it has 2 sides: apical faces the lumen, and basal faces inward.
4
Q
What are some examples of connective tissue?
A
- Bone: bone-forming cells are called osteoblasts which create a matrix of collagen. Calcium, Mg, and phosphate ions exist in the matrix. The unit cell for bone is the osteon.
- Blood: liquid matrix called plasma with water, salts, and proteins. In addition, erythrocytes (red blood cells), leukocytes exist (white blood cells), and platelets (cell fragments involved in clotting) exist inside.
- Adipose tissue: loose connective tissue storing fat in adipose cells that pad an insulate the body.
- Cartilage: collagen fibres in a protein-carbohydrate complex. Its strong but also flexible, common in embryos before replaced by bone.
5
Q
What is a functional trade-off?
A
When the specialization for one function limits the ability to preform another function as well or at all (example skin is semi-permeable to loose water but then is not as protective).
6
Q
Explain how hierarchy in a system can show effects in 2 directions (i.e., small can affect larger system but larger system can also affect small).
A
If there is a problem with a biological system it can show effects on the smallest units: cells, as well as organs within. (Ex: problem with the brain shows problems in all cells)
But a problem with a single part can also affect the overall system/organism. (Ex: knee injury affects musculoskeletal system when other muscles need to compensate leading to overall locomotion problems).
7
Q
What is an emergent property?
A
A property determining the overall function
- Ex: a cell is an emergent property of life, an eye is an emergent property of sensing light.
- Non-Ex: a nose is not an emergent property of smell, nose receptors are.
8
Q
What is interstitial fluid?
A
The fluid that inhabits the space between cells.
9
Q
What is negative feedback and what is its relationship to homeostasis?
A
A control mechanism that responds opposite to the stimulus, to return to the baseline body level and maintain homeostasis (reduces the disturbance).
Involves a stimulus, a sensor (perceiving the stimulus), and a control centre that determines how to respond and initiate.
10
Q
What is positive feedback?
A
A control mechanism that reinforces the original stimulus; not aiming to maintain homeostasis, but to drive something ti competition. Ex: birth.
11
Q
What are examples of homeostatic set points that change in the body over time?
A
- Puberty and menopause (hormone levels)
- Cyclic cycles like circadian rhythms and menstrual cycle.
- Acclimatization (responding to environmental changes, more than just 1)
- Acclimation (responding to 1 environmental change).
12
Q
What is a resource trade-off?
A
When natural selection favours efficiency of resources, leading to trade offs between resources and energy.
Ex: Seals don’t digest their fish until above surface, so more oxygen can be provided to brain, heart, and locomotive processes.
13
Q
What is a model organism? What is the one used for in fertilization research? In morphogenesis research?
A
An organism that can easily be studied for a particular process that is representative for a wide range of species.
In fertilization, the sea urchin is used.
In morphogenesis and cleavage: frog.
14
Q
What is the acrosomal reaction?
A
When the hydrolytic enzymes released from the acrosome on a sperm eat through the jelly layer or the egg. The acrosomal process then forms from the actin filaments of the sperm, which penetrates the jelly coat and its proteins bind to the sperm receptors on the egg’s plasma membrane.
15
Q
What are the 2 ways polyspermy is prevented in fertilization?
A
- Fast block: once the sperm is bound to the receptors on the egg, the two nuclei fuse. This allows the sodium channels to open up in the egg, depolarizing it, and creating an approx. 1 minute block.
- Slow block: the cortical reaction: the granules in the egg fuse with the eggs plasma membrane (in between the vitelline layer called the perivitelline space). This removes the sperm receptors, and hardens the vitelline layer to form a fertilization envelope.
16
Q
What is “egg activation” and what is necessary for it to occur.
A
Calcium ions initiate the cortical reaction, or the activation of the egg, in which the fertilization envelope is formed.
17
Q
What is the rapid cell divisoo stage following fertilization?
A
Cleavage: rapid cell divisions that skip the G1 and G2 phase of the cell cycle, essentially creating a mass of cell the same size as the initial zygote. These cells are called blastomere or a blastula cell. The collection of cells has a hollow fluid-filled interior known as the blastocoel.
18
Q
What are the 2 poles of the blastula?
A
Vegetal pole and animal pole, which describes the distribution of stored nutrients or “yolk”.
Vegetal pole: more yolk concentration
Animal pole: opposite pole, less concentration.
These poles then differ in appearance because of this.
19
Q
What are the 2 main factors that contribute to different looking or different structured cells?
A
Gene expression is responsible, and does this in 2 main ways:
- Cytoplasmic determinants: molecules in cytoplasm that regulate gene expression. The determinants in each cell are determined by cleavage and which pole the cell was in, and of course further replications.
- Inductive signalling: Signals the cell is exposed to, depends on location of cell in the embryo and the stage of development.
20
Q
What are the 3 germ layers and at what stage are they developed?
A
The reorganization of the hollow blastocoel in gastrulation creates the 3 germ layers:
- Ectoderm (outer): blue
- Mesoderm (middle): red
- Endoderm (inner): yellow, lines the digestive tract
21
Q
What process forms the preliminary digestive tract and what is the preliminary version called?
A
The invagination of the blastocoel wall on the vegetal pole creates a deeper, narrow tube called the archenteron. This tube will form the digestive tract, with the open end forming the anus which is called the blastopore.
In this process the blastocoel disappears.
22
Q
What are the 2 processes of morphogenesis?
A
- Gastrulation: rearrangement of the cells in the blastocoel, creating the 3 germ layers and the archenteron.
- Organogenesis: formation of organs, beginning with neurulation.
23
Q
What is convergent extension and what is one of its applications?
A
The rearrangement of cells in a sheet that become narrower (converge) and longer (extend). This process is used in neurulation.
24
Q
Explain the process of neurulation.
A
The neural plate develops from ectoderm tissue, that sits above the notochord. It begins the neural fold, eventually completely pinching to first form the neural crest (connecting the soon to be neural tube and the outer ectoderm that pinched in) and second become the neural tube.
The neural tube then sits above the notochord, covered in ectoderm tissue with a bump where the neural tube/spine exists.
25
What are the 2 main organs responsible for regulating the endocrine system?
1. The hypothalamus (nervous tissue)
| 2. Pituitary gland (endocrine cells) which is beside the hypothalamus
26
Explain the interaction between the pituitary gland and the hypothalamus
The posterior pit. gland is made up of axons of neurosecretory cells from the hypothalamus, in which release hormones directly into the blood.
The anterior pit. gland is endocrine cells that respond to hormones from the hypothalamus via portal vessels. The hormones control what hormones are subsequently released.
From there, these hormones released from pituitary gland control hormones released in other glands.
27
Explain the fight of flight response in terms of the hypothalamus and endocrine system.
Stress arrives at the hypothalamus which causes a nerve impulse down the spinal cord to the adrenal medulla, which secretes epinephrine and norepinephrine.
28
Explain how water-insoluble hormones and water-insoluble hormones differ in their pathways.
Water soluble cells require release from cell by a vesicle as they can't pass over the lipid bilayer. However, they can freely pass into the blood stream and out. They require a receptor on the surface of the cell, meaning they must go through signal transduction before creating gene expression/activity.
Water-insoluble on the other hand don't require a vesicle to pass out of the cell, but they require a transport protein while passing though the blood. When they reach the target cell they can pass through and go right to the nucleus for gene expression (no transduction needed usually).
29
Why do hormones show different responses in target cells?
1. The type of receptor it binds to. Each receptor only has one specific hormone, but a hormone may have different types of receptors (i.e., alpha and beta form).
2. The signalling pathway/proteins within the cell (ex. a receptor in different cells in the body will show different results: in liver norepinephrine receptor will release glucose as a response, in skeletal-vessel area the response will be vessel dilation for the same signal and receptor).
30
What is an antagonistic hormone?
A pair of hormones that have opposing functions/responses.
31
Describe the role of insulin and glucagon in the cell.
Insulin is released by beta cells in the pancreas when blood glucose is high, it causes glucose to be stored in the liver.
Glucagon is produced by alpha cells in the pancreas when blood glucose is low, it causes the liver to convert the stored glycogen to be converted to glucose and travel into the blood.
You can see here how these two can be a combined loop of events.
32
In general, how does the nervous system send signals throughout the body?
They send signals via electrical impulses. These impulses are very fast, much faster that endocrine, and the duration is short (typically external stimuli from immediate stimuli).
Neurotransmitters are also involved, brining a chemical aspect of signalling.
33
In general, how does the endocrine system send signals throughout the body?
Through hormones that travel; through the blood to target cells. This process can vary in speed and duration, but is specialized for gradual changes over the body and affecting a larger portion (than electrical), if not the whole, body.
34
What are glial cells?
Cells in the nervous system that help maintain homeostasis, by creating myelin (fatty substance covering the axons of neurons) to protect and support cells in the CNS and PNS.
35
What composes the CNS? The PNS?
CNS=brain and spinal cord
| PNS=cranial nerves, spinal nerves, ganglia of cells outside of CNS (bundles of nerves from CNS)
36
What are the 3 stages of information processing in the nervous system?
1. Sensory input (in PNS)
2. Integration (CNS)
3. Output (e.g., motor function) (CNS)
37
Explain how the motor, sensory, and inter-neuron interact when sending an electrical signal.
The stimuli activates the sensory neuron, travelling to the spinal card for processing. From there the impulse goes 2 ways: to the motor neuron for direct response (faster) and to the brain via an interneuron for complete processing of the stimulus (slower).
This explains why reaction can be a lot faster than understanding, ex: putting hand on hot surface.
38
Compare BMR to metabolic rate.
Metabolic rate is the energy used by an animal/time.
| BMR is energy used/time when on an empty stomach, no stress, and for an endotherm.
39
Explain the relationship between BMR and Mass.
BMR increases with mass, however, the larger the animal the more efficient they are with their energy use (if based on energy used/unit mass on that animal larger animals will have lower).
BMR=mass^(3/4)
40
4 ways that you can measure an animals energy usage?
1. O2 consumption
2. Co2 production
3. Food consump. + waste elim.
4. Heat production (metabolism)
41
What are the 4 different types of feeders?
1. Suspension+filter (e.g., whale)
2. Substrate (consuming on which you life, e.g., caterpillar)
3. Fluid (e.g., mosquito, hummingbird)
4. Bulk feeders (most land mammals).
42
What are some of the digestive/ingestive differences between herbivores, omnivores, and carnivores?
1. Teeth: carnivores have larger canines and incisors with jagged molars. Omnivores have flatted, chunky molars.
2. Cecum: first part of the intestine, responsible for fermenting plants, so carnivores ave basically non-existent, and omnivores have very large one.
43
Explain the process of pepsin production and where it occurs.
Pepsinogen is secreted by chief cells located in gastric glands in the stomach. Parietal cells in the same gland release HCl, which activates the pepsinogen into pepsin.
Pepsin is an enzyme for protein.
44
What are some of the ways self-digestion is prevented?
1. Mucos on stomach wall
2. HCl and other digestive enzymes are kept in their inactive form until released into the lumen
3. Theres a rapid turnover of digestive cells
45
How is fat digested?
Fat is digested through emulsification by liver bile. Bile is produced in the liver, stored in the bile, and released into the intestine for breakdown.
46
What is the main purpose of the colon?
Water reabsorption and elimination of feces.
47
Is energy is needed by the animal what is the sequential order from where it obtains it from their body?
1. Glycogen in the liver
2. Glycogen in the muscles
3. Fat from adipose tissue
48
Explain the hormones involved in the satiety centre and hunger.
1. Leptin is produced by adipose and regulates long term appetite.
2. Insulin + PYY are secreted in response to a meal (decrease glucose levels)
3. Grenhim released when stomach is empty
49
How is the small intestine adapted for food absorption?
It contain a very large surface area: many folds an vili, which then contain microvilli. These microvilli are also in very close contact with blood supply for prompt absorption.
50
How is diffusion optimized (what characteristics?)?
Optimized by large surface area and a thin layer (small distance).
51
What are the 3 basic components in any circulatory system?
1. Circulatory fluid: blood, hemolymph
2. Set of connections: vessels
3. Muscular Pump: heart
52
What creates the "lub-dub" sound of the heart?
1. Lub come from the atrial systole and the ventral dystole: blood flowing into ventricles via the AV valves.
2. The dub sound is from the atrial dystole and the ventral systole: blood is pumped from the ventricles via semi-lunar valves to either the body via the aorta, or the lungs via the pulmonary arteries.
53
What is the structure of capillaries?
It is a single epithelial cell think covered in basal lamina (protein an such coating).
54
How does the body regulate blood flow? (stucture wise not hormone).
Blood flow can be regulated by nerve pulses, hormones, or local chemicals that can either affect the arterty/arteriole diameter or by regulating the pre-capillary sphincters.
Typically only 5-10% of capillaries have blood flow through them, if affected by a hormone that loosens the pre-cap sphincters then more blood will flow through.
55
What are the characteristics of capillaries in terms of area, pressure, and speed? What does this mean for the blood flow in that area?
Capillaries have a higher area because of the increased branching, meaning there is a slower movement of blood and decreased pressure.
This allows for easy transport of blood solubles to the interstitial fluid.
56
What are the components of blood?
1. Plasma (liquid portion, 55%): contains water, ions, nutrients, metabolites, and waste.
2. Cellular components (45%): erythrocytes, leukocytes, and platelets.
57
What are alveoli and what is their function?
Alveoli are sacs of air at the end of the bronchioles on the lungs. They are covered in capillaries because they function to exchange O2 and Co2 with the blood, to bring O2 in and get rid of the co2 waste.
58
How does oxygen travel through the blood?
Oxygen travel by binding to a hemoglobin molecule, which has 4 binding sites.
59
How does Co2 travel thought the blood?
In the plasma as soluble Co2 (7%), bound to amino acids on hemoglobin molecule (23%), and in the plasma as bicarbonate (70%,) which helps to buffer the blood.
60
How do land and aquatic animals vary in their respiratory process?
Respiration requires a moist location: gills are in the water, lungs are kept inclosed to prevent water loss.
Because water contains significantly less oxygen, aquatic animals almost 4x more efficient at respiration.
61
What are 3 barriers of innate human response on the external?
1. Skin/nails/other coverings
2. Internalized external surfaces like mucosa
3. Secretions like tears, saliva, mucos, etc.
62
What is the difference between innate and adaptive immunity?
Innate immunity occurs in all animals and is a very rapid response as it has a small set of receptors.
Adaptive immunity is only for vertebrates and is a slower response due to the vast array of receptors
63
What are the 4 types of internal defences in innate response? (don't describe just list).
1. Natural killer cells
2. Phagocytic cells
3. Antimicrobial proteins
4. Inflammation
64
What are natural killer cells?
They are active as an innate immune response by which they identify infected or cancerous cells (host cells) and released chemicals to allow apoptosis.
65
What are interferons?
A type of anti-microbial protein involved in innate immune response that are secreted by infected cells. They then release chemicals to notify surrounding cells to stop viral reproduction.
66
Explain local and systemic inflammation.
Local: Production of histamine occurs, where it causes vasodilation in that area as well as increases vessel permeability (allow white blood cells to enter).
Cytokines further increase blood flow
Systemic: Production of increasing amount of white blood cells from bone marrow and the reset of the body's thermostat (to increase chemical reaction rates).
67
How is pathogen-specific recognition achieved in adaptive immunity?
Via antigens (on foreign/pathogenic cells) and antigen receptors (on host cells, either T or B cells).
68
What is an epitope?
An epitope is a specific binding site on the surface of the antigen in which a T or B cell recognizes (each individual T or B cell recognizes only 1 epitope).
69
How do B cell antigen receptors bind to antigens?
They bind to antigens found on the surface of the pathogen or that has been secreted by the pathogen, in the lymph or the blood (in fluid: humoral response).
70
How do T cell antigen receptors bind to antigens?
T cells only bind to antigen fragments, either on the pathogen or on a phagocytic cells that has moved the pathogens contents onto its surface.
71
Explain how phagocytic cells and pathogens put antigen fragments on their surface.
After a phagocytic cell engulfs a pathogen, it breaks down its contents and then either eliminates it via exocytosis, or it can hold onto fragments and put it on its surface via an MHC molecule.
T cells can then bind to this surface complex.
Infected cells do the same.
72
What happens after a T or B cell is bound to its antigen (on surface or in liquid or as a fragment)?
The B or T cell first proliferates (the slow response associated with adaptive immunity , and then some become memory cells and some become effector cells.
73
What are memory cells and what are their purpose?
Memory cells are T or B cells that have proliferated. They function to remember the surface antigens of particular pathogens so that they can initiate a fast response once exposed to that pathogen again.
74
What do effector B cells become and what do they do?
Effector B cells mature into plasma cells and they secrete antibodies into the plasma.
75
What is an antibody and what is its purpose?
An antibody is secreted by a plasma cells as a soluble form of an antigen receptor which can bind to antigens.
76
What are the 3 ways free moving antibodies mark pathogens for inactivation or destruction?
1. Neutralization: the binding of the antibody to the antigen prevents that infectious cell from binding/communicating with a host cell.
2. Opsonization: the binding to the antigen allows phagocytic cells to recognize the pathogenic cells more easily, so they can engulf and digest them.
3. Activation of complement system + pore formation: antibodies attached to antigens can bind with free-roaming complement proteins. This binding activates complement proteins, forming a membrane-attack-complex that forms pores in the foreign cell. This causes the cell to lyse.
77
What do effector T cells become?
Effector T cells become either helper T cells or cytotoxic T cells.
78
What to helper T cells do?
They do not destroy pathogens but they help to activate B and Cytotoxic T cells.
They do this once they are attached to an antigen fragment on a phagocytic cells. The phagocytic cell releases cytokines once attached to the helper T cell, which causes the Helper T cell to release its own cytokines. These cytokines then activate B or cytotoxic Tc cells.
79
What do cytotoxic T cells do?
They bind to antigen fragments on infected cells and then release either Perforin or granzymes
Perforin creates pores in the cell causing it to lyse, similar to what complement proteins do with B cells.
Granzymes trigger apoptosis.
80
What are the 3 types of skeletons?
1. Hydrostatic: no hard structure, just fluid held under pressure.
2. Endoskeleton
3. Exoskeleton.
81
Describe worm locomotion (a type of hydrostatic locomotion).
Worms have longitudinal and circular muscles. When one is relaxed, the other in contracted. The alternating contracts and relaxations, along with bristles securing the worm to the ground, allow movement.
82
What are antagonistic muscles?
2 muscles that when paired together they do the opposite movement (i.e., one contracts one relaxes).
83
What are skeletal muscles made of?
Muscle fibres (cells) composed of myofibrils that are made of thin and thick filaments (actin and myosin, respectively).
84
What is the functional unit of the skeletal muscle?
The sarcomere, consisting on inter-joined actin and myosin filaments.
85
Explain what happens in the sarcomere during contraction.
The myosin head binds to the myosin binding site on the actin filament once in its high energy configuration (dephosphorylation of ATP, at a 90 deg. angle).
This forms a cross bridge, and the myosin head goes back to its low energy configuration, pulling the actin filament to the M line of the sarcomere, and pulling the 2 Z lines closer together (increasing overlap).
86
What initiates the contraction of muscle?
Calcium Ions released by the trigger of a motor neuron.
The calcium bind to the troponin complex, causing the tropomyosin to move off of the myosin binding sites and allow myosin to bind.
87
When does contraction of muscle stop?
When calcium ions stop (motor neuron stops sending signal) or ATP runs out (responsible for attaching myosin head to actin).
88
What is the dominant opposing force of lotion on land? What are some adaptations to this?
The dominant opposing force is gravity. This is why terrestrial animals require powerful muscles and strong bones.
Springy tendons are an example in kangaroos.
Balance: bipedals require one foot on the group when walking, multi-footed require 3 or groups of 3 on the group. When running, all feet can be off the ground due to momentum
89
What is the opposing force in aquatic animals and what are some adaptiations.
Most aquatic animals are relatively buoyant and so gravity doesn't play a large role (but in terrestrial diving animals passive descent is a behavioural adaptation because eof gravity).
The main opposing force is friction (or drag) and so the fusiform body helps reduce this.
90
What is the opposing force in air locomation and what are some adaptations?
Drag is the most dominant opposing force (along with gravity as second).
This is why many flying birds have a low body mass, mostly hollow bones, no teeth, and no urinary bladder.
91
What are 2 ways animals can act to a parameter?
1. Conformer: allows internal conditions to change in response to external conditions
2. Regulator: use homeostatic mechanisms to control internal changes.
They can be different for different parameter in the same animal.
92
What are 2 reasons why conformers can conform?
1. They may have adequate physiology and anatomy to tolerate the "drastic" changes
2. The environment in which they live doesn't show drastic changes in that environment.
93
Whats the difference between endothermy and ectothermy?
- Endotherms use metabolism as a heat source
| - Ectotherms' temperature varies with the external environment.
94
What are ways animals can maintain temperature?
1. Insulation
2. Evaporative heat loss
3. Behavioural responses (also by ectotherms)
4. Circulatory adaptations
5. Metabolic heat production
95
What are some circulatory adaptations?
1. Vasoregulation: control of arterial diameter achieved via nerve impulses and hormones.
2. Countercurrent heat exchange: heat transfered between fluids in opposite directions (heat from warm blood transfers to veins in closer proximity maintaining even temperature).
96
What are some examples of metabolic heat production?
1. Muscle contraction: shivering is an unconscious example (produces heat)
2. Brown adipose tissue (only in some mammals): in brown adipose tissue there is a high concentration of mitochondria (brown appearance) so there is a lot of cellular respiration, producing a lot of heat
Typically in infant mammals or small mammals
97
What are the 3 different physiological parameters being controlled in osmoregulation?
1. Total solute concentration
2. Individual solute concentration
3. Body Water (volume)
98
What is hyper, hypo, and iso-tonic solutions?
Hypertonic: high solute concentration, low free water
Hypotonic: low solute concentration, high free water
Isotonic: even concentrations
99
What will happen to a cell if placed in a hypo and hypertonic solution (separately)?
1. If placed hypotonic solution water will flow into the cell, bloating the cell, and potentially causing lysis.
2. If placed in a hypertonic solution water will flow out of the cell, dehydrating the cell (shrivel and die).
100
Whats an osmoconformer and an osmoregulator?
An osmoconformer is one thats isotonic with the environment, only possible in marine animals as freshwater is too low solute and so is air. (still needs to actively transport specific ions within the body).
An osmoregualtor can be found in marine, freshwater, and terrestrial animals where the internal osmolarity is achieved by actively transporting solutes in and out of cells.
