final:biodiversity

Question 1

How molecular phylogeny can be used to determine the evolutionary relationship between different species

Answer 1

a) Compared by DNA profiling,
b) Sequences of bases
c) Amino acid sequences
d) The more similarities in sequences, the closer the relationship/ they have a more recent shared common ancestor.

Question 2

How molecular phylogeny could show that there are three different species?

Answer 2

a) Compare DNA/RNA? Proteins
b) There are different base sequences, showing that there are different species.

Question 3

How did zoos determine the species?

Answer 3

1. Breed the (animal) and (captive animal) to see if fertile offspring produced
2. Analysis of molecular evidence of the (captive animal)
3. And compare it to the (animal) to see how similar sequences area
4. Compare the phenotype of (captive animal) to (animal)

Question 4

How to determine change in frequency of allele?

Answer 4

1. DNA analysis to identify different alleles
2. Use Hardy-Weinberg equation (p2 +2pq +q2)
3. To compare allele frequency in the previous generation with the current generation.

Question 5

How could they confirm that it was different species of Archaea?

Answer 5

1. Molecular phylogeny, analysis of molecular evidence
2. To identify similarities and differences in biological molecules
3. Analysis of phenotype ie. their habitats/ growing conditions
4. To identify similarities and differences between the phenotypes of the organisms

Question 6

How to determine which is the most closely related?

Answer 6

1. Molecular phylogeny, analysing DNA base sequence, amino acid sequence
2. Through gel electrophoresis, compare the bands (amino acid +DNA ok)
3. Species with most similarities are most closely related

Question 7

Scientific Community reviewing

Answer 7

a) Scientist proposed reclassification in a scientific journal
b) Peer review of molecular evidence was carried out
c) The experiment was repeated by other scientists
d) Analysis was extended to look for more similarities and differences in more genes
e) More research, statistical analysis was done.

Question 8

Explain why taxonomic groupings of living organisms have changed over the year and why they may continue to change (3)

Answer 8

1. Classification was based on anatomy/ morphology
2. Improved microscopes
3. Use of molecular phylogeny
4. More new species will be and have been discovered
5. In the future, technology will continue to develop

Question 9

Difficult to interpret factors affecting phenotype?

Answer 9

1. Phenotype determined by both genotype and environment
2. Genotype may not be known

Question 10

Eukaryota VS Bacteria

Answer 10

1. Eukaryota has membrane bound organelles but bacteria doesn’t
2. Eukaryota doesn’t have plasmids/slime capsule/ pili which are found in bacteria
3. Eukaryota has larger ribosomes (80s) while bacteria has smaller (70s)
4. DNA is nucleus in eukaryota
5. Eukaryotic cells have linear DNA but bacteria (prokaryotic) cells have circular DNA

Question 11

**Natural selection question (ALWAYS ASKED)

Answer 11

1. There is genetic variation in the (species) population
2. Mutations produce new alleles, contributing to genetic variation
3. (Describe change in environment), leading to selection pressure
4. (species) with (advantageous phenotype) have (apply), and hence less competitive pressure
5. (species) with advantageous phenotype) are more likely to survive and reproduce
6. The advantageous allele coding for (advantageous allele) is passed onto offspring
7. # Proportion of (species) with advantageous allele increases over time
8. There is geographical isolation (*depends on the question)
   a. Ie. In Madagascar the lemurs are separated from other monkeys because they are located in different places. The Lemurs are only found in Madagascar.
   b. Ie. Saddleback tortoise and domed tortoises are located on different islands

Question 12

Natural selection-> *Question about endemic (lemurs)

Answer 12

1. Lemurs are only found on Madagascar
2. Geographical isolation
3. Because of change in environment, there was selection pressure
4. Natural selection occurred
5. Result in new species/ new gene pools
6. Which adapted to conditions

Question 13

Describe how biodiversity of the area can be measured

Answer 13

1. Determine genetic diversity of a species
2. By the number of alleles present
3. By calculating the heterozygosity index

Question 14

Describe how heterozygosity index can be calculated

Answer 14

1. Analyse DNA/ find out number of heterozygotes/ population size
2. Divide number of heterozygotes by total population number

Question 15

How species richness is calculated?

Answer 15

1. Count the number of species
2. Count the size of the habitat

Question 16

Suggest how effects of () on biodiversity could be measured (ASKED A LOT)

Answer 16

1. Measure species richness
2. By counting the number of different species in a specified area
3. Compare before and after habitat loss (or apply to the specific event)
4. Compare loss of () with the loss of biodiversity <- effects of ash dieback on biodiversity Q

Question 17

Increase biodiversity

Answer 17

• Conservation, breeding programmes
• Succession, Immigration
• Reafforestation

Question 18

Decrease biodiversity

Answer 18

• Hunting/ predation
• Loss of habitat
• Climate change/ pollution/ farming/ natural disasters
• Disease, Inbreeding
• Emigration

Question 19

Low genetic diversity affecting survival of species

Answer 19

1. Small gene pool and low variety of alleles
2. Less chance of advantageous allele for resistance to disease
3. Lower chance of survival and increased possibility for extinction

Question 20

Decrease in population size resulting in reduced genetic diversity

Answer 20

1. Increased chance of inbreeding, leading to genetic disease
2. Which would reduce the gene pool

Question 21

Two difference between genetic diversity and species richness

Answer 21

1. Genetic diversity considers species, species richness considers different number of species
   2.Genetic diversity considers alleles, species richness considers number of species in an area.

Question 22

Endangered, why?

Answer 22

1. Deforestation causing habitat loss
2. Reduction in food due to competition with other species/ deforestation/ overfishing(apply)
3. Pollution making it unsuitable habitat
4. Disease/ hunting, causing death

Question 23

Seed banks to conserve genetic diversity of plant species

Answer 23

1. Harvest large number of seeds from different plants of the same species
2. Collected seeds from different locations
3. Ensuring there is a variety of alleles and large gene pool in seeds collected

Question 24

Storage conditions of seed banks

Answer 24

1. Lower temperature
2. Lower humidity
3. To reduce growth of bacteria and fungi
4. To reduce enzyme and metabolic activity

Question 25

Why are seeds dried/ no water

Answer 25

1. Reduce enzyme and metabolic reactions 2. Reduce microbial growth/ decay/ decomposition 3. Prevent damage when seeds are frozen 4. Prevent germination of seeds

Question 26

Suggest why seed germination is tested at regular intervals

Answer 26

1. Check seed viability 2. To see if more seeds need to be collected.

Question 27

Explain how seed banks ensure that seeds can remain viable for long periods of time (5)

Answer 27

1. Seeds are X-rayed to check for viability 2. Seeds are dried before storage 3. Seeds are stored at very low temperatures 4. Seeds stored in low humidity 5. (2)(3) To prevent growth of fungi 6. (2)(3) To reduce metabolic and enzyme activity 7. Germinate seeds at regular intervals to check for viability

Question 28

Why seed banks store seeds instead of growing plants

Answer 28

1. Take up less space 2. Less maintenance and costs 3. Seeds survive longer than plants because they can be frozen.

Question 29

Description of breeding programme

Answer 29

1. Use DNA profiles to select mates 2. Exchange animals between zoos 3. To reduce inbreeding and encourage outbreeding 4. Hence preventing genetic drift 5. And to introduce alleles from other populations

Question 30

Suggest how captive breeding programme could lead to the development of a population able to survive this disease in the wild (4)

Answer 30

1. Alleles with resistance to the disease 2. Pass on the alleles to offspring 3. Increasing number of individuals with immunity 4. Using IVF/ embryo splitting/ surrogates to increase number of offspring 5. Re-introduction into the wild 6. Increasing the frequency of those alleles in the wild population

Question 31

Suggest how captive breeding programme could maintain the genetic diversity of Koalas in Australia

Answer 31

1. Zoos select (Koalas) from different areas (in Australia) 2. Exchange animals between zoos 3. Use stud books to select mates and to prevent inbreeding and encourage outbreeding 4. Hence preventing genetic drift 5. Use IVF and use Use DNA profiles to select mates

Question 32

Zoos working together to ensure success

Answer 32

1. Exchange animals between centers 2. Keep breeding records 3. Share resources 4. Quarantine and not breed with sick animals 5. Do not release too many (species) into one area