Unit 2 Revision

Question 1

Risk assessment

Answer 1

Identifies potential hazards.
Assess the likelihood of them occurring.
Describes steps to minimise their occurrence.

Question 2

Hazards associated with fieldwork

Answer 2

Terrain
Weather conditions
Isolation
Tide

Question 3

Point Count

Answer 3

Recording all individuals seen from a fixed point.

Question 4

Elusive species can be sampled using…

Answer 4

Camera traps
Scat sampling

Question 5

Taxonomy

Answer 5

Naming and classifying organisms into groups based on their characteristics.

Question 6

Model organisms and their taxonomic groups

Answer 6

Nematode: Caenorhabditis elegans
Bacterium: Escherichia coli
Arthropoda: Drosophila melanogaster

Question 6

Gametocytes

Answer 6

The precursors of male and female gametes.
Formed inside red
blood cells and released
into the bloodstream when red
blood cells burst.

Question 7

What is a model organism?

Answer 7

One that has been extensively studied and/or is easy to study.
Very important in the advancement of modern biology

Question 8

Nematodes are…
Arthropods are…
Chordates are…

Answer 8

worms.
insects.
vertibrates.

Question 9

Phylogenetics looks at…

Answer 9

morphology, DNA sequences, and protein structure.

Question 10

What does mark and recapture assume?

Answer 10

All individuals have an equal chance of capture.
There is no immigration or emigration.
Individuals that are marked and released can mix randomly with the whole population.

Question 11

Methods of marking

Answer 11

Banding
Tagging
Surgical Implantation
Painting
Hair clipping

Question 12

Natural selection and sexual selection are __________ processes.

Answer 12

Non-random

Question 13

Genetic drift is a ______ process.

Answer 13

Random

Question 14

Genetic drift

Answer 14

Occurs when chance events
cause unpredictable fluctuations in allele frequencies.
More important in small populations as alleles are more likely to be lost from the gene pool.

Question 15

Rate of evolution is rapid when…

Answer 15

Selection pressures are strong.

Question 16

HW equation

Answer 16

p^2 + pq + q^2 = 1
p = frequency of dominant allele
q = frequency of recessive allele
p^2 = frequency of homozygous dominant genotype
2pq = frequency of heterozygous genotype
q^2 = frequency of homozygous recessive

Question 17

Absolute fitness

Answer 17

frequency of a particular genotype before selection

Question 18

Relative fitness

Answer 18

number of surviving offspring per individual of the most successful genotype

Question 19

Mutualism

Answer 19

Both organisms gain from the relationship, the interaction is (+/+).

Question 20

Commensalism

Answer 20

Only one of the organisms
benefits (+/0).

Question 21

Parasitism

Answer 21

Parasite benefits and the host is harmed as the result of the loss of these resources (+/-).

Question 22

How do asexually reproducing organisms increase variation

Answer 22

Horizontal gene transfer.

Question 23

Linked genes

Answer 23

Genes on the same chromosome

Question 24

Non-specific defence examples

Answer 24

Physical barriers
Chemical secretions
Inflammatory response
Phagocytes
Natural killer cells

Question 25

Natural killer cells

Answer 25

Identify and attach to
cells infected with viruses, releasing chemicals that lead to cell death by inducing apoptosis.

Question 26

Specific cellular defences

Answer 26

If tissues become damaged or invaded, cells release cytokines that increase blood flow
resulting in white blood cells accumulating at the site of infection or tissue damage.