Biodiversity And Classification

Question 1

What is a species?

Answer 1

Group of similar organisms with similar features that can reproduce to produce fertile offspring

Question 2

Explain what is meant by a hierarchy

Answer 2

Groups wishing groups with no overlap

Question 3

Explain what is meant by a phylogenic group

Answer 3

Groups based on evolutionary links

Question 4

Explain what is meant by genetic diversity

Answer 4

Difference in DNA

Question 5

Explain what is meant by species richness

Answer 5

Number of different species within a community

Question 6

Explain how natural selection produces changes within a species

Answer 6

Mutation causes variation within a species
Gives organism an Advantage against selection pressures such as predators
Organism lives long enough to reproduce and pass on advantageous allele to offspring
Over a long period of time
Changes in allelic frequency occur

Question 7

Explain why an index of diversity would be more useful measure of biodiversity

Answer 7

Measures number of organisms within each species
Some species may have too little individuals

Question 8

Describe how comparisons of two biological molecules could be used to find out wether they are closely related

Answer 8

Compare DNA sequence and amino acid sequence
DNA hybridisation
Break hydrogen bonds between strands
By heating it
Inject protein into a animal
Obtain antibodies
Add protein from another species
Amount of precipitate indicates relationship

Question 9

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. 3points

Answer 9

Base sequence longer than amino acid sequence
Contains introns
DNA code is degenerate

Question 10

What is meant by a genetic bottleneck. 2point

Answer 10

Sudden decrease in population
Reducing genetic variation

Question 11

Suggest on ethical reason to maintain biodiversity

Answer 11

Prevent extinction

Question 12

Suggest one economical reason as to maintaining biodiversity

Answer 12

Medical uses
Tourism

Question 13

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

Answer 13

Reduced variety of plants
Reduced feeding sites
Reduced niches
Reduced herbivores so reduced carnivores
Insects migrate to places with more food or die

Question 14

Describe how courtship behaviour increases probability of successful mating. 5points

Answer 14

Organism does a specific behaviours
Done to attract the opposite sex of the right species
Indicates sexual maturity
Stimulates release of gametes forms a pair bond

Question 15

How can scientists use protein structure to investigate the evolutionary relationships between different species

Answer 15

Compare amino acid sequence
Closer the amino acid sequence the close the relationship
As the DNA sequence is related to base sequence

Question 16

Describe the processes that lead to a reduction in genetic diversity of populations of organisms.

Answer 16

Decrease in variation
Due to selection pressures such as increased competition for resources
Few individuals from population become isolated
Causes genetic bottle neck
where there is a sudden decrease in population
Leading to selective breeding of those with alleles that survived
Particular alleles