Biodiversity, species and taxonomy A1

Question 1

What is a species?

Answer 1

1. group of similar organisms
2. reproduce
3. to produce fertile offspring

Question 2

What is meant by genetic diversity?

Answer 2

difference in DNA / base sequence / alleles / genes

Question 3

What is meant by biodiversity?

Answer 3

number of species and number of individuals of each of the species within any one community

Question 4

What is meant by species richness?

Answer 4

a measure of the number of different species within the community

Question 5

What is meant by the term community?

Answer 5

all the individuals of all the species living together in the same area at the same time.

Question 6

What information is needed to calculate the index of diversity?

Answer 6

1. number of species overall (total)
2. number of individual species

Question 7

Why is index of diversity a more useful method of measuring biodiversity?

Answer 7

1. also measures n. of individuals in a species
2. some species may be present in low/high numbers

Question 8

Name two advantages of using index of biodiversity rather than indicator species?

Answer 8

1. you do not need to identify each species
2. index takes into account n. of organisms of each of the species

Question 9

Give one economic reason for maintaining biodiversity (5 marks)

Answer 9

1. medical use
2. commercial products
3. tourism
4. agriculture
5. saving local forest communities

Question 10

After a forest was cleared, the species diversity of insects in the area decreased. Explain why?

Answer 10

1. fewer plant species
2. fewer habitats/niches
3. fewer food sources
4. aspects of cleaning forests (machinery/pesticides)
5. fewer species of herbivore so fewer carnivores

Question 11

Explain what is meant by hierarchy?

Answer 11

1. groups within groups
2. with no overlaps between groups

Question 12

Explain what is meant by a phylogenetic group.

Answer 12

grouped according to evolutionary history / common ancestry

Question 13

Give the way in which courtship increases the probability of successful mating?

Answer 13

1. attracts same species
2. attracts opposite sex
3. indication of sexual maturity
4. stimulates release of gametes
5. form a pair bond

Question 14

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

Answer 14

1. more bases (triplets) than amino acids / longer base sequence than amino acid sequence
2. introns / non-coding DNA
3. degenerate coding / more than one code for each amino acid

Question 15

Give two ways doctors could use base sequences to compare different types of HPV.

Answer 15

1. compare DNA base sequence
2. compare mRNA base sequence
3. look for mutations

Question 16

Describe how comparisons of biological molecules in this species (seahorse) could be compared to find out if they are closely related.

Answer 16

1. compare DNA
2. sequence of bases/nucleotides
3. compare cytochrome (mitochondria) same/names protein
4. sequence of amino acids/primary structure
5. inject seahorse protein/serum into animal
6. add protein from other seahorse species
7. amount of precipitate indicates relationship

Question 17

Explain the principles which biologists use to classify organisms into groups.

Answer 17

1. large groups divided into smaller groups
2. members of a group have features in common based on anatomy/DNA
3. reflects evolutionary history

Question 18

What is meant by species diversity?

Answer 18

number of species in a community

Question 19

Suggest how information of amino acid sequence is used to construct a phylogenetic tree?

Answer 19

1. those with similar sequences put in same group/more closely related
2. greater difference in amino acid sequence the longer ago the groups diverged

Question 20

State two ways other than DNA and mRNA base sequence that genetic diversity between species can be observed?

Answer 20

1. comparing observable characteristics
2. comparing amino acid sequence of the same/named sequence

Question 21

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

Answer 21

1. reduced variety/number of different alleles/DNA/reduced gene pool (in new populations)
2. founder effect
3. a few individuals from a population become isolated from colonies
4. genetic bottlenecks
5. significant fall in size of population
6. selective breeding / artificial selection
7. using organisms with particular alleles/traits/phenotypes/characteristics

Question 22

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

Answer 22

1. amino acid sequences / primary structure
2. closer the amino acid sequence, the closer the relationship
3. protein structure related to DNA base/triplet sequence

Question 23

What is meant by a genetic bottleneck?

Answer 23

1. drop in population / many killed by an event eg. earthquake
2. idea of reduced/low genetic variation/diversity/reduction in variety of alleles / smaller gene pool

Question 24

Suggest one advantage and one disadvantage to using protein X to construct a phylogenetic tree?

Answer 24

advantage - present in all species organisms
disadvantage - extinct species not considered / no timing of events available / only limited n. of amino acid sequences

Question 25

State 3 comparisons of genetic diversity use in order to generate classification Y.

Answer 25

1. DNA sequence 2. mRNA sequence 3. amino acid sequene

Question 26

Give two ways a student could ensure their index of diversity was representative of each habitat?

Answer 26

1. random sampling 2. large number of samples / until stable running mean

Question 27

Give 4 biological benefits of replanting hedgerow?

Answer 27

1. increase biodiversity 2. source of food for animals 3. habitats 4. windbreaks

Question 28

Give one ethical reason for maintaining biodiversity?

Answer 28

prevents extinction / loss of diversity

Question 29

Explain the importance of taking a large sample at random?

Answer 29

1. produces reliable / representative mean 2. removes bias

Question 30

Molecule Y are chemically similar molecules found in many different species. Differences in the primary structure of haemoglobin molecule can provide evidence of phylogenetic relationships between species. Explain how?

Answer 30

1. mutation changes base sequence 2. causes change in amino acid sequence 3. mutations build up over time 3. more mutations/differences between distant related species 5. distant related species have earlier common ancestor OR closely related species have recent common ancestor

Question 31

Give the taxonomic rank of organisms in order of hierarchy.

Answer 31

1. domain 2. kingdom 3. phylum 4. class 5. order 6. family 7. genus 8. species

Question 32

What is the calculation for diversity index?

Answer 32

Total n. of individual organisms /(divided by) n. of individuals of a particular species

Question 33

What term is used to describe the method of naming organisms by genus and species?

Answer 33

Binomial nomenclature