9.3 Genetic diversity and adaptation

Question 1

What can similarities and differences in organisms be determined as

Answer 1

Variation in DNA

Question 2

What is a gene

Answer 2

A section of DNA that codes for a polypeptide

Question 3

What is genetic diversity

Answer 3

The total number of different alleles in a population

Question 4

What is a population

Answer 4

A group of individuals of the same species that live in the same place and can interbreed

Question 5

What are differences in characteristics caused by

Answer 5

Which two alleles of a gene they possess

Question 6

What causes greater genetic diversity

Answer 6

Greater number of alleles in a population

Question 7

What does greater genetic diversity mean in terms of survival

Answer 7

That it is more likely some individuals in a population will survive an environmental change

Question 8

Why does greater genetic diversity increase survivability for organisms experiencing an environmental change

Answer 8

Because of a wider range of alleles and therefore a wider range of characteristics. This gives a greater probability that some individuals will possess a characteristic that suits it to the new environmental conditions

Question 9

Why are not all alleles of a population equally likely to be passed to the next generation

Answer 9

Because only certain individuals are reproductively successful and so pass on their alleles

Question 10

Describe the process of how successful alleles are passed onto the next generation

Answer 10

1. Within any population of a species there will be a gene pool containing a wide variety of alleles
2. Random mutation of alleles within the gene pool may result in a new allele of a gene which in most cases will be harmful. However, in certain environments, the new allele of a gene may be advantageous over other individuals
3. These individuals will be better adapted and therefore more likely to survive in their competition with others. These individuals will be more likely to obtain the available resources to grow and so live longer
4. Only those that successful reproduce will pass on their alleles - therefore slowly, the advantageous allele becomes increasingly more common within a population and the disadvantageous allele becomes less common. (allelic frequency)