bio test genetic diversity

Question 1

What is genetic diversity?

Answer 1

The number of different alleles within a population.

Question 2

What is a population?

Answer 2

A population is a group of the same species in the same place that can interbreed.

Question 3

What is the advantage of more genetic diversity?

Answer 3

More genetic diversity + more alleles means a wider range of characteristics/variation (bigger gene pool), which leads to a greater chance of individuals surviving environmental change.

Question 4

What is the model paragraph for mutations and selection pressures?

Answer 4

1. A change in environment causes a selection pressure.
2. Random mutations produce genetic diversity.
3. Some alleles provide an advantage to gaining resources.
4. Those individuals with the alleles survive and reproduce.
5. Advantageous alleles are passed on.
6. The frequency of advantageous alleles in the population increases.
7. The frequency of mutation increases.

Question 5

What decides if a mutation is advantageous?

Answer 5

Nature and natural selection.

Question 6

What are the features of variation between species?

Answer 6

Different species have different genes, they may also have a different number of chromosomes, they cannot breed to produce fertile offspring and have different features.

Question 7

What is selection?

Answer 7

The process by which organisms that are better adapted to their environment survive and reproduce, while those who are less well adapted do not.

Question 8

What is selection pressure?

Answer 8

An environmental change that leads to selection.

Question 9

What is continuous variation?

Answer 9

A characteristic that can have a wide range of values. Producing a histogram shows a ‘bell shaped’ normal distribution curve.

Question 10

What is discontinuous variation?

Answer 10

A characteristic with few possible values shows discontinuous variation. The graph does not show a bell curve.

Question 11

What are polygenic traits?

Answer 11

characteristics that are controlled by mutiple genes/alleles

Question 12

What is direction selection?

Answer 12

Favouring individuals whose characteristics vary from the mean; phenotypes are selected for genotypes are indirectly selected. Changes characteristics.

Question 13

What is stabilising selection?

Answer 13

If conditions remain stable, individuals with average characteristics are favoured; phenotypes at the extremes are selected against. Preserves characteristics.

Question 14

Why do organisms reproduce?

Answer 14

Organisms reproduce to ensure they survive over time; the females of most species produce eggs at specific times. This places a selection pressure on courtship behaviours.

Question 15

What are the features of courtship behaviour?

Answer 15

Allows individuals to:
1. Recognise members of the same species.
2. Identify a sexually mature mate.
3. Form a pair bond that will lead to successful mating and raising of offspring.
4. Synchronise mating so that it takes place at a time where egg and sperm are most likely to meet.
5. Become able to breed by bringing a member of the opposite sex into a state that allows breeding to occur.

Question 16

What is artificial classification?

Answer 16

Grouping organisms based on features that are useful at the time, e.g. colour wings. The evolutionary origin of these features may not be taken into account.

Question 17

What is phylogenetic classification?

Answer 17

Based on evolutionary relationships determined from fossils, DNA analysis; based on shared homologous features.

Question 18

What are hierarchies?

Answer 18

Groups within groups that do not overlap.

Question 19

What are the different taxonomic ranks?

Answer 19

Domains (divine), kingdom (kings), phylum (play), class (chess), order (on), family (fat), genus (green), species (stools).

Question 20

What are the benefits of classification?

Answer 20

Universal.

Question 21

What is species diversity?

Answer 21

The number of different species in a community and their proportions.

Question 22

What is genetic diversity?

Answer 22

The frequency of different alleles within a population.

Question 23

What is ecosystem diversity?

Answer 23

The number of different habitats that make up an ecosystem.

Question 24

What is species richness?

Answer 24

The number of different species in a community. It only tells you the number of species in an area and not the proportions of individuals.

Question 25

What is the index of diversity?

Answer 25

A quantitative measure of biodiversity.

Question 26

How do you calculate the index of diversity?

Answer 26

d = N(N-1)/En(n-1), where d = species diversity index, N total is the number of individuals of all species, n = no. of individuals of each species.

Question 27

What is a natural ecosystem?

Answer 27

An ecosystem consists of a community of organisms and the habitats in which they live.

Question 28

What is an artificial ecosystem?

Answer 28

An ecosystem that is controlled by humans; farmers select which species are allowed to grow there. They have a low genetic diversity, species richness and index of diversity.

Question 29

What impact do artificial ecosystems have on biodiversity?

Answer 29

By reducing competition, few species dominate; genetic diversity decreases; species richness decreases; index of diversity decreases; fewer habitats; variety of plants/insects/animals decrease; variety of food decreases.

Question 30

How can we determine evolutionary relationships?

Answer 30

Comparing physical characteristics, comparing proteins/enzymes, compare amino acids, compare mRNA sequences, compare DNA sequences.

Question 31

How are mutations linked to DNA sequencing?

Answer 31

Organisms accumulate random mutations over time; more closely related species show more DNA similarities. This allows for phylogenetic classification.

Question 32

How do you compare mRNA sequences?

Answer 32

mRNA is complimentary to DNA from which it is transcribed. Therefore, species that share similar mRNA sequences are more closely related.

Question 33

How do you compare amino acid sequences?

Answer 33

Amino acid sequences are determined by mRNA sequences, which are determined by DNA sequence. More closely related species will have more similarities in amino acid sequences.

Question 34

How can you compare species using immunological comparisons?

Answer 34

Antibodies of one species will respond to specific antigens on proteins in the blood serum of another. Serum containing the antigen from species A is injected into species B. Species B produces antibodies specific to all the antigen sites on the antigen from species A. The serum is extracted from species B. This serum contains antibodies specific to the antigens in serum A. Serum from species B is mixed with serum from the blood of a third species C. The antibodies respond to their corresponding antigens in the serum of species C. The response is a formation of a precipitate. The greater the number of similar antigens, the more precipitate and vice versa. Higher precipitate = a more closely related species.

Question 35

How do you measure variation?

Answer 35

Most characteristics show continuous variation; this makes it impossible to give them a definitive measurement value. You can get around this by sampling.

Question 36

What is sampling?

Answer 36

Looking at smaller groups of organisms and using them to represent the whole population.

Question 37

What are the errors that can be made when sampling?

Answer 37

May show bias like choosing where to collect samples.

Question 38

What is random sampling?

Answer 38

Draw a grid over a map of the land; use a random number generator to generate coordinates; place the quadrant at coordinates. This eliminates sampling bias.

Question 39

How can you do random sampling with leaves?

Answer 39

Number the leaves; place numbered balls in a bag; select balls at random.

Question 40

What are the downsides of sampling?

Answer 40

Chance. Even without bias, the measured value may be down to chance, e.g. 50 chosen buttercups may all happen to be tall ones.

Question 41

How can you reduce the impact of chance?

Answer 41

Increase sample size or more/bigger quadrats.

Question 42

How do you display variation?

Answer 42

If you measured a characteristic of a population that showed continuous variation under stable conditions, it would present a normal distribution: symmetrical, mean, median and mode values are the same.

Question 43

Why may a distribution curve be skewed?

Answer 43

This may be because of insufficient sampling or an external factor/selection pressure favouring a characteristic.

Question 44

What is the standard deviation?

Answer 44

The spread of data about the mean. The bigger the standard deviation, the greater the variation.

Question 45

How do you calculate the standard deviation on a calculator?

Answer 45

1. Press mode. 2. Select STAT. 3. Select 1--VAR. 4. Enter the first measurement and press = to enter it. 5. Continue to enter other measurements, pressing enter each time. 6. When done, press M+ to add values to memory. 7. Clear screen and press shift. 8. Press STAT button. 9. Select 'sx' if calculating s.d for a sample or press 'OX' if calculating s.d for a whole population. 10. Press M+. 11. The number given is the standard deviation.

Question 46

What does it mean if the standard deviation in two sets of data overlaps?

Answer 46

The results are not significant

Question 47

What is interspecific variation?

Answer 47

Variation in characteristics between species.

Question 48

What is intraspecific variation?

Answer 48

Variation in characteristics between members of the same species.

Question 49

How can you reduce the impact of chance in sampling?

Answer 49

Carry out a statistical test - this tells you exactly how confidently you can be that the result is not due to chance. We usually aim to be 95% confident.

Question 50

What are the 5 kingdoms?

Answer 50

- animalia, plantae ,fungi protocista, prokaryotae.. - all eukaryotic domains have dna in a membrane bound nucleus.

Question 51

what are the three domains?

Answer 51

- eukarya - archaea - bacteria