Animal Structure and Function

Question 1

Why do structures evolve the way they do?

Answer 1

Adaptation through natural selection allows organisms to evolve certain structures as a result of functional outcomes.

Question 2

Difference between anatomy and physiology?

Answer 2

Anatomy: features evolved to allow for survival

Physiology: biological processes taking place through the anatomy

Question 3

What does a large membrane surface area allow for? Give 3 examples of this.

Answer 3

Greater rate of exchange of nutrients, waste products, gases. (e.g. Villi in small intestine allow for maximal absorption of nutrients, porous lung tissue allows for maximal absorption of oxygen, Kidney tubules allows for maximal reabsorption of nutrients.

Question 4

What does evolutionary convergence reflect?

Answer 4

Adaptations to a similar environmental challenge coupled with the constraints of physical laws resulting in similar structures (size and shape).

Question 5

How does exchange of metabolites occur?

Answer 5

Substances dissolved in aqueous medium diffuse and are transported across the plasma membrane of cells.

Question 6

What is an element of multicellular organization that is required for it to function?

Answer 6

Equal access to suitable aqueous environment to allow for equal distribution of nutrients.

Question 7

What is interstitial fluid?

Answer 7

fluid outside of the body’s cells and outside of the blood vessels that allows for movement of material into and out of cells.

Question 8

What is a pro and on of complexity in a multicellular organism?

Answer 8

Pro: allows for maintenance of relatively stable internal environment in a variable external environment

Con: Energy expensive and relies on coordination.

Question 9

What is the hierarchal organization of cells and what does each do?

Answer 9

1. Cells: smallest unit of life.
2. Tissues: group of specialized cells with specific functions
3. Organs: part of an organism made of multiple tissues functioning as one unit.
4. Organ system: a collection of organs that perform a vital function

Question 10

What are the four main categories of tissues and their functions?

Answer 10

1. epithelial tissue: closely joined cells that cover the outside of the body and line the organs/cavities within the body
2. connective tissue: sparsely packed cells throughout an extracellular matrix that binds and supports other tissues.
3. muscle tissue: long fibrous cells that contract in response to nerve signals.
4. nervous tissue: senses stimuli and signals throughout the animal.

Question 11

What are the 7 types of epithelial tissue?

Answer 11

Simple cuboidal, simple squamous, simple columnar, stratified cuboidal, stratified squamous, stratified cuboidal, pseudo-stratified columnar, transitional.

Question 12

What is located in the connective tissue’s extracellular matrix? What state is the substance of the matrix?

Answer 12

fibroblasts: secrete fibre proteins

macrophages: engulf foreign particles and cell debris

Matrix consists of liquid, jellylike or solid fibers.

Question 13

What are 6 types of connective tissue and their functions?

Answer 13

1. Loose connective tissue: collagenous and elastic fibres for strength and flexibility
2. Fibrous connective tissue: attach muscles to bones and connect bones to joints
3. Bone tissue: mineralized connective tissue (osteo- cells) that forms the skeleton
4. Cartilage: a strong and flexible support material made of chondrocytes
5. Adipose tissue: stores fat for insulation and fuel
6. Blood: composed of erythrocytes, leukocytes, and cell fragments in blood plasma.

Question 14

What are the two types of muscle fibres?

Answer 14

Skeletal muscle: aka striated muscle, attached to bones and responsible for voluntary movement

Smooth muscle: many lines internal organs and is responsible for involuntary body activities

Question 15

What is the nervous tissue composed of?

Answer 15

Neurons: nerve cells that transmit nerve impulses

Glial cells/glia: help nourish, insulate and replenish neurons

Question 16

Control and coordination within a body depend on which systems? What’s the difference?

Answer 16

endocrine system: transmits hormones to receptive cells throughout the body via blood.

nervous system: transmits information between specific locations

Question 17

What is a hormone?

Answer 17

Regulatory substances made by one tissue to stimulate action in another tissue. Can be either fast or slow acting, but can have long-lasting effects.

Question 18

What does nervous signalling and endocrine signalling depend on?

Answer 18

Nervous signalling: pathway of signal

Endocrine signalling: type of signal

Question 19

What are two ways animals manage their internal environment and how do they differ?

Answer 19

Regulator: uses energy to fuel internal control mechanisms to moderate internal change in the face of external environmental fluctuation

Conformer: allows internal condition to vary with external environment.

Question 20

Homeostasis

Answer 20

a self-regulating process by which a living organism can maintain internal stability while adjusting to changing external conditions

Question 21

How does a negative feedback loop work?

Answer 21

1. variable fluctuates above/below a set point and serves as stimulus
2. Stimulus is detected by a sensor and triggers a response
3. Response returns the variable to set point. (e.g. thermoregulation)

Question 22

How does a positive feedback loop work?

Answer 22

1. variable fluctuates above/below a set point and serves as stimulus
2. stimulus is detected by a sensor and triggers a response
3. response intensifies a response until an endpoint is reached (e.g. childbirth/blood clotting)

Question 23

What is the difference between acclimation and acclimatization?

Answer 23

Acclimation: adjusting to a single environmental factor

Aclimatization: adjusting to complex changes in external environment

Question 24

What is thermoregulation?

Answer 24

Process by which animals maintain and internal temperature within a tolerable range.

Question 25

What is the difference between an endothermic and an ectothermic individual?

Answer 25

Endothermic: generate heat via metabolism (e.g. birds, mammals)

Ectothermic: gain heat from external sources (e.g. reptiles, amphibians, fish, invertebrates)

Question 26

what’s the difference between a poikilotherm, a homeotherm, and a heterotherm?

Answer 26

Poikilotherm: body temp varies with environment

Homeotherm: body temp is relatively constant

Heterotherm: maintains different temperatures in specific regions of the body

Question 27

What are the 4 physical process by which organisms exchange heat?

Answer 27

conduction, convection, radiation and evaporation.

Question 28

What is the integumentary system?

Answer 28

Mammalian method of regulating heat: includes skin, hair and nails

Question 29

What are the five general adaptations that help animals thermoregulate?

Answer 29

1. Insulation
2. Circulatory adaptations
3. Cooling by evaporative heat loss
4. behavioural responses
5. adjusting metabolic heat production

Question 30

How does insulation regulate heat?

Answer 30

Insulation, present in mammals and birds, use skin, feathers, fur and blubber to reduce heat flow between an animal and its environment.

Question 31

How do circulatory adaptations regulate heat?

Answer 31

Vasoconstriction/dilation: increase/reduce blood flow in the skin increases/reduces heat exchange with the environment

Countercurrent heat exchange: arrangement of blood vessels in marine mammals and birds allows heat transfer between fluids flowing in opposite directions

Question 32

How does cooling by evaporative heat loss regulate heat?

Answer 32

Sweating or bathing moistens the skin, cooling an animal down as the heat from the skin surface is absorbed by the water to evaporate.

Question 33

How do behavioural responses regulate heat?

Answer 33

Some terrestrial invertebrates have postures that minimize or maximize absorption of solar heat.

Question 34

How does adjusting metabolic heat production regulate heat?

Answer 34

Muscle activity produces heat and adipose tissue have thermogenin proteins that causes the mitochondria to produce heat.

Question 35

What’s osmoregulation?

Answer 35

regulation of solute concentration in body fluids through the osmotic gain and loss of water. It is based largely on controlled movement of solutes between internal fluids and the external environment.

Question 36

What is osmolarity? What are the three levels of osmolarity?

Answer 36

Osmolarity is the solute concentration of a solution (osmoles of solute per litre of soution). Can be isosmotic, hyposmotic, and hypersmotic.

Question 37

What is the difference between osmoconformers and osmoregulators? Marine examples.

Answer 37

Osmoconformers: isosmotic with their surroundings and do not regulate osmolarity (e.g. marine invertebrates)

Osmoregulators: use energy to control water uptake in a hyposmotic environment and water loss in a hyperosmotic environment (marine vertebrates and invertebrates)

Question 38

What is the difference between a stenohaline animal and a euryhaline animal?

Answer 38

Stenohaline: cannot tolerate substantial changes in external osmolarity

Euryhaline: survive large fluctuations in external osmolarity

Question 39

What is the relationship between osmotic strategy (regulator/conformer) and osmotic tolerance (stenohaline/euryhaline)

Answer 39

There is no relationship or correlation between osmotic strategy and osmotic tolerance.

Question 40

How do saltwater osteichthyes and freshwater osteichthyes regulate their osmolarity in seawater?

Answer 40

Saltwater: By drinking seawater and excreting salt ions in scanty urine, they maintain their hyposmolarity to saltwater.

Freshwater: By taking in salts through the gills and excreting large amounts of water in dilute urine, they maintain their hyperosmolarity to freshwater.

Question 41

What is smoltification?

Answer 41

Complex series of physiological changes where young salmonid fish adapt from living in fresh water to living in seawater

Question 42

What is transport epithelia?

Answer 42

Specialized cells that regulate solute movement and are essential components of osmotic regulation and metabolic waste disposal. They are arranged in complex tubular networks.