Mutations EGR

Question 1

Most phenotypic features are the result of _______ rather than single gene inheritance.

Answer 1

multiple genes

This indicates that traits are often influenced by the interaction of several genes.

Question 2

What are the causes of variation that influence phenotype?

Answer 2

• Genetic variation
• Environmental factors

Genetic variation arises from mutations and environmental factors can affect how traits are expressed.

Question 3

Discuss the outcomes of the Human Genome Project.

Answer 3

• Mapping the human genome
• Enabling personalized medicine
• Developing new gene therapies
• Improving diagnostics for genetic disorders
• Predicting disease risk

These outcomes have significant implications for medical treatments and understanding genetic conditions.

Question 4

There is usually extensive genetic variation within a population of a species, arising through _______.

Answer 4

mutations

This variation is crucial for the process of natural selection.

Question 5

Most genetic mutations have _______ effect on the phenotype.

Answer 5

no

Some mutations may have small effects, while very few significantly impact the phenotype.

Question 6

What is a mutation?

Answer 6

A change in the sequence of DNA

Mutations can lead to variations in traits and can be caused by various factors.

Question 7

Why is it difficult to identify how inherited characteristics are controlled?

Answer 7

• Many characteristics are influenced by multiple genes
• Genes can interact in complex ways
• Environmental factors can affect development

This complexity makes genetic inheritance challenging to study.

Question 8

How can mutations cause variation?

Answer 8

By altering the DNA sequence

Changes in DNA can lead to different traits being expressed.

Question 9

True or false: Most mutations are harmful.

Answer 9

FALSE

Most mutations are harmless and have no effect on the phenotype.

Question 10

What is the average mutation rate in human cells?

Answer 10

0.000000025 mutations per base per generation

This rate can be influenced by environmental factors.

Question 11

What can increase the mutation rate?

Answer 11

• Ionising radiation (UV, gamma rays)
• Carcinogens (chemicals that increase mutation)

Fast-dividing cells tend to acquire mutations more quickly.

Question 12

What is an allele?

Answer 12

A different version of a gene

Alleles contribute to genetic diversity within a population.

Question 13

What is the genotype?

Answer 13

The genes an organism possesses

The genotype determines the potential traits of an organism.

Question 14

What is the phenotype?

Answer 14

The physical characteristics of an organism

Phenotype results from the interaction of genotype and environmental factors.

Question 15

Give an example of a mutation that causes a disease.

Answer 15

Sickle cell anaemia

This condition is caused by a single mutation that affects hemoglobin.

Question 16

How does the sickle cell mutation provide an advantage?

Answer 16

It protects against malaria

Sickle-shaped red blood cells are harder for the malaria parasite to infect.

Question 17

What is the scientific term for the instructions that create a functioning protein?

Answer 17

Genes

Genes provide the necessary information for protein synthesis.

Question 18

What happens if one of the instructions (genes) is missing or incorrect?

Answer 18

The protein may not function properly

This can lead to various health issues or diseases.