the origin of the phenotype

Question 1

What is a phenotype?

Answer 1

Any observable characteristic of an organism, such as its morphological, developmental, biochemical or physiological properties, or its behaviour

Phenotypes can be influenced by genetics and environmental factors.

Question 2

What aspects of an organism’s phenotype are derived from its parents?

Answer 2

Some aspects of an organism’s phenotype are derived by inheritance from its parents

This highlights the genetic contribution to phenotypic traits.

Question 3

What can cause other aspects of an organism’s phenotype?

Answer 3

Effects of the environment upon the organism

Environmental factors can significantly alter the expression of phenotypic traits.

Question 4

What is the interplay that can affect an organism’s phenotype?

Answer 4

Interplay of environment, development, up-bringing, genetics, and chance

This complex interaction illustrates the multifactorial nature of phenotypes.

Question 5

What is the ACE gene?

Answer 5

A gene that encodes an enzyme called ‘Angiotensin-Converting Enzyme’

The ACE gene is crucial in regulating blood pressure and fluid balance.

Question 6

What does the ‘I’ allele confer?

Answer 6

‘I’ allele confers improved endurance

‘I’ stands for ‘Insertion’ and signifies a genetic advantage under certain conditions.

Question 7

What does the ‘D’ allele confer?

Answer 7

‘D’ allele confers diminished endurance

‘D’ stands for ‘Deletion’ and is associated with lower endurance capabilities.

Question 8

What are the three genotype/phenotype combinations for endurance?

Answer 8

• II which confers greatest endurance
• ID which confers intermediate endurance
• DD which confers the lowest endurance

These combinations illustrate the genetic basis for endurance performance.

Question 9

How do II individuals respond to training?

Answer 9

II individuals have increased endurance after training

This indicates a positive response to training in individuals with the II genotype.

Question 10

How do DD individuals respond to training?

Answer 10

DD individuals showed no increase in endurance, and if anything got worse

This suggests a lack of adaptability in response to training for the DD genotype.

Question 11

What is the function of the ACE enzyme?

Answer 11

Converts a hormone called angiotensin into a form that tightens blood vessels

This function is critical in understanding how the ACE gene affects endurance.

Question 12

How does low activity of the ACE enzyme affect endurance?

Answer 12

Low activity → looser vessels → raised heartbeat → greater endurance; associated with the II genotype

This mechanism illustrates the physiological basis for endurance differences.

Question 13

How does high activity of the ACE enzyme affect endurance?

Answer 13

High activity → narrowed vessels → slower heartbeat → lower endurance; associated with the DD genotype

This shows the contrasting effects of ACE enzyme activity on endurance.

Question 14

True or False: If you’re II, you will dominate in endurance sports.

Answer 14

False

Performance differences may not be as significant as assumed, and training can impact outcomes.

Question 15

What might other training regimes lead to regarding genotype performance?

Answer 15

Equal improvements for both, or even greater improvements in the DD individuals

This highlights the importance of training methods in determining performance outcomes.

Question 16

What does GxE interactions refer to?

Answer 16

Differences that different genotypes make will be greater or lesser or non-existent depending on the types of environment

This illustrates the complexity of gene-environment interactions in phenotypic expression.