Predicted Questions

Question 1

Explain what is meant by the term species.

Answer 1

• Idea that the species is reproductively isolated.
  -Produce fertile offspring
  -Many common features/homologous.
  (anatomically, structurally, behaviorally similar)

Question 2

Explain what is meant by endemic species.

Answer 2

Idea of the species being found in only one specific geographical location.

Question 3

Explain what is meant by the term niche.

Answer 3

A niche is the functional role of an organism in its habitat.

Question 4

Name the 3 domains of organisms.

Answer 4

eukarya, archaea, bacteria

Question 5

Three species of sloth (Bradypus, Cholepus didactylus, Choleus hoffmanni) are described. It’s belived that Choleus.D and Choleus.H shared a common ancestor before becoming isolated. Explain why they are now classed as different species.

Answer 5

-No longer able to interbreed and produce fertile offspring.

-Populations have become reproductively isolated

Question 6

How does seperate evolution occur?

Answer 6

Idea of geographical isolation, different habitats, different selection pressures, mutation resulted in adaptation, decreased gene flow, reproductive isolation.

Question 7

Type of bond between adjacent amino acids.

Answer 7

Peptide bond

Question 8

Reaction involved in formation of peptide bond.

Answer 8

Condensation

Question 9

Draw structure of amino acid.

Answer 9

H H O
N C C
H R OH

Question 10

Describe amino acid structure.

Answer 10

Amino group, carboxyl group attached to central carbon. Central carbon has an R group and hydrogen attached.

Question 11

Explain what is meant by the term molecular phylogeny.

Answer 11

molecular differences/similarities in amino acid sequences, base sequence of DNA/RNA, in proteins, relationships between organisms

Question 12

Explain role of o2 in aerobic respiration.

Answer 12

Oxygen is the final electron acceptor in the electron transport chain. This enables oxidative phosphorylation to occur in order for ATP to be synthesised.

Question 13

Explain the need for reduced NAD to be oxidised in the mitochondria of the sloth.

Answer 13

-Hydrogen can be delivered to the electron transport chain.
-to allow ATP synthesis
-to regenerate NAD to keep KREB cycle going

Question 14

Sloths can be possible hosts for arthropod-borne viruses. Describe the structure of a virus.

Answer 14

Contain nucleic acid (DNA or RNA) surrounded by a protein coat. A viral envelope may be present, as well as enzymes like DNA integrase. Glycoproteins on the surface for attachment to host cell receptors.

Question 15

Monomer that makes up cellulose?

Answer 15

Beta-glucose

Question 16

Cellulose held together by bundles called microfibrils. These are embedded into matrix containing Calcium Pectate. Where is Calcium Pectate found?

Answer 16

The middle lamella

Question 17

Describe the structure of a cellulose microfibril.

Answer 17

-Contains beta glucose
-joined by condensation reaction
-have 1-4 glycosidic bonds
-unbranched chain
-cellulose chains held together by hydrogen bonds.

Question 18

What chemical reaction takes place to break down/decompose sloth dung?

Answer 18

Hydrolosis

Question 19

Role of bacteria in the decomposition of sloth dung?

Answer 19

Decomposition is the breakdown of organic matter.
Bacteria produces hydrolytic enzymes.
The organic matter gives the bacteria the substrates it needs for respiration.

Question 20

What would temp increase do to rate of decomposition of sloth dung?

Answer 20

Increase rate of decomposition increases. Hydrolytic enzymes gain more kinetic energy. More enzyme/substrate molecules.
Increase in rate at which bacteria can increase.
Optimum temp.
Enzymes can denature due to high temps.

Question 21

How is increased sweating involved in the regulation of body temp?

Answer 21

heat from blood in capillaries absorbed by sweat, used to break H+ bonds in water, water evaporates, taking heat from body, resulting in cooling.

Question 22

Describe the role of the hypothalamus in maintaining steady internal temp.

Answer 22

Thermo-receptors detect temp change.
Impulses sent to the thermoregulatory control centre.
Hypothalamus sends impulse via motor neurones to appropriate named effector.
Vasodilation happens.

Question 23

Tendons are:

Answer 23

Flexible, non-elastic tissues connecting bone to muscle.

Question 24

Ligaments are:

Answer 24

Flexible tissue connecting bone to bone.

Question 25

Similarities of slow/fats twitch muscle fibres

Answer 25

Contain actin/myosin.
Consist of sarcoplasm, sarcomeres

Question 26

Differences between slow/fast twitch muscle fibres.

Answer 26

Slow have more mitochndria.
Slow have more myoglobin.
Slow have less glycogen
Slow have less creatine

Question 27

What is tensile strength?

Answer 27

The pulling force the fibre can withstand before breaking.

Question 28

How can tensile strength of sloth muscles/tendons be determined?

Answer 28

Cut a strip of muscle or tendon and record thickness and length of tendon or muscle. Hnag masses of equal intervals onto the strip until it splits. Repeat at least 3 times. Calculate tensile strength by dividing force by cross-sectional area.