Biodiversity & Classification

Question 1

What is meant by biodiversity? (1)

Answer 1

number of individuals of each species within the community

Question 2

Q
What is meant by species richness? (1)

Answer 2

number of different species in a community

Question 3

What is meant by a community? (1)

Answer 3

ALL individuals of ALL species living together in the same area at the same time

Question 4

Q
What is a species? (2)

Answer 4

1. Group of similar organisms
2. Reproduce to produce fertile offspring

Question 5

Q
Explain what is meant by a hierarchy? (2)

Answer 5

A
1. Groups within groups
2. No overlap between groups

Question 6

Explain what is meant by a phylogenetic group (1)

Answer 6

A
grouped according to evolutionary links

Question 7

Explain what is meant by genetic diversity (1)

Answer 7

difference in DNA base sequence

Question 8

Explain what is meant by a niche (2)

Answer 8

A
1. An organisms role in the community / ecosystem
2. How organisms interact with other species and responds to the environment

Question 9

Q
How to calculate diversity index?

Answer 9

A
( N (n - 1) ) / sum of n (n-1)
N = total number of organisms of ALL species
n = total number of organisms of EACH species

Question 10

Q
What information is required to calculate an index of diversity for a particular community? (2)

Answer 10

1. Number of species
2. Number of individuals of each species

Question 11

List the order of the hierarchy. Start with the largest group.

Answer 11

A
1. Domain
2. Kingdom
3. Phylum
4. Class
5. Order
6. Family
7. Genus
8. Species

Question 12

Give two ways doctors could use base sequences to compare different types of HPV (3)

Answer 12

A
1. Compare DNA base sequence
2. Compare mRNA base sequence
3. Look for mutations

Question 13

State three comparisons of genetic diversity that the scientist could have used to generate a classification (3)

Answer 13

1. DNA base sequence
2. mRNA base sequence
3. Amino acid sequence

Question 14

The number of species present is one way to measure biodiversity. Explain why an index of diversity may be a more useful measure of biodiversity.

Answer 14

1. Measures number of individuals in a species
2. Some species may be present in low/high numbers

Question 15

In classification, comparing the base sequence of a gene provides more information than comparing the amino acid sequence for which the gene codes. Explain why. (3)

Answer 15

1. More bases than amino acids / longer base sequence than amino acid sequence
2. Introns/non-coding DNA;
3. Same amino acid may be coded for / DNA code is degenerate

Question 16

Scientists’ analysis of blood proteins has indicated a lack of genetic diversity in populations of some organisms. Describe the processes that lead to a reduction in the genetic diversity of populations of organisms. (6)

Answer 16

1. Reduced variety/number of different alleles / reduced gene pool
2. Founder effect
3. A few individuals from a population become isolated/form colonies
4. Genetic bottlenecks
5. (Significant) fall in size of population
6. Selective breeding / artificial selection
7. Using organisms with particular alleles / phenotypes / characteristics

Question 17

Scientists can use protein structure to investigate the evolutionary relationships between different species. Explain why. (3)

Answer 17

1. Amino acid sequences / primary structure
2. Closer the amino acid sequence the closer the relationship
3. Protein structure related to (DNA) base sequence

Question 18

A forest was cleared to make more land available for agriculture. After the forest was cleared the species diversity of insects in the area decreased. Explain why. (4)

Answer 18

1. Decrease in variety of plants / fewer plant species
2. Fewer habitats and niches
3. Decrease in variety of food / fewer food sources
4. Clearing forest resulted in killing insects due to machinery or pesticides

Question 19

What is meant by a genetic bottleneck? (2)

Answer 19

A
1. Sudden decrease in population / many killed by an event eg earthquake
2. Reduced genetic variation / reduction in (variety of) alleles

Question 20

Suggest one ethical argument for maintaining biodiversity. (1)

Answer 20

Prevent extinction
Prevent reduction in populations
Prevent loss of habitats

Question 21

Suggest three economical arguments for maintaining biodiversity. (3)

Answer 21

1. Medical uses
2. Commercial products
3. Tourism
4. Agriculture
5. Saving local forest communities

Question 22

Farmers clear tropical forest and grow crops instead. Explain how this causes the diversity of insects in the area to decrease. (4)

Answer 22

1. Fewer plant species
2. Fewer food sources
3. Fewer habitats and niches
4. Fewer (species of) herbivore so few (species of) carnivores
5. Clearing forest resulted in killing insects due to machinery or pesticides

Question 23

Describe how courtship behaviour increases the probability of successful mating. (5)

Answer 23

1. Attracts same species
2. Attracts mate/opposite sex
3. Allows sexual maturity/ fertility / synchronises mating
4. Stimulates release of gametes
5. Form pair bond