CB3E/F Gene mutation

Question 1

What are the two causes of variation within a species

Answer 1

Genetics
Environment

Question 2

What is a genetic variation

Answer 2

Variations in the genotypes of organisms of the same species due to the presence of different alleles

Creates differences in phenotypes

Question 3

What creates genetic variation in a species

Answer 3

Spontaneous mutations
Sexual reproduction

Question 4

What is a mutation

Answer 4

A random change to the base sequence in DNA which results in genetic variants

Question 5

State the three types of gene mutation

Answer 5

Insertion
Deletion
Substitution

Question 6

How may a gene mutation affect an organisms phenotype (3)

Answer 6

Neutral mutatuon does not change the sequence of amino acids. Protein structure and function same. No effect on phenotype

Mutation may cause a minor change in an organisms phenotype e.g change in eye colour

Mutation may completely change the sequence of amino acids. This may result in a non-functional protein. Severe changes to phenotypes

Question 7

What is environmental variation

Answer 7

Variations in phenotypes that are acquired during the lifespan of an organism

Due to the environmental factors e.g diet, lifestyle, climate exposure to light etc

Question 8

What is the Human Genome Project

Answer 8

Scientific research project involving thousands of scientists across the globe which successfully mapped the entire human genome

Scientists now aim to identify the function of every gene in the human genome

Question 9

How can the results of the Human Genome Project be applied to medicine

Answer 9

Enables scientists to understand how lifestyle factors interact with genes - identifying predisposition to disease and possible preventions

Disease-causing alleles identified more rapidly and the appropriate treatments prescribed earlier on

Scientists can predict an individual’s response to certain drugs. New drugs can be developed which are tailored to a specific allele

Question 10

What are the drawbacks associated with the discoveries of the Human Genome Project

Answer 10

Knowledge of predisposition to a disease can be stressful

Societal pressure influencing the decision to have children

Discrimination by employers insurance firms etc