Mutations

Question 1

Define evolution.

Answer 1

The change in characteristics of a species overtime.

Question 2

Define Genotype.

Answer 2

The genetic makeup of an organism.

Question 3

Define phenotype.

Answer 3

The observable characteristics in an individual resulting from the expression of genes.

Question 4

Define population.

Answer 4

A group of organisms of the sam e species living together in a particular place at a particular time.

Question 5

Define gene pool.

Answer 5

The grouping of genotypes and the sum of all alleles in a given population.

Question 6

Define allele frequencies.

Answer 6

Is how common an allele is in a given population.

Question 7

What are the two types of mutations?

Answer 7

1. Gene mutations
2. Chromosomal mutations

Question 8

What are mutations?

Answer 8

Are changes in the DNA sequence of an organism.

Question 9

What are gene mutations?

Answer 9

Change in a single gene so that the traits normally produced by that gene are destroyed or changed.

Question 10

What are chromosomal mutations?

Answer 10

All or part of a chromosome is affected. A mutation involving a long segment of DNA or chromosomes. It can occur when the number of chromosomes increases or decreases in a genome as well as when chromosome structure change occurs.

Question 11

What are the causes of mutations?

Answer 11

Mutagenic agents or mutagens.

Question 12

What are 5 examples of mutagens/mutagenic agents?

Answer 12

1. Mustard gas
2. Formaldenyde
3. Sulfur dioxide
4. Some antibiotics and ionizing radiation (UV + X-rays)
5. Radiation

Question 13

What are induced mutations?

Answer 13

Are caused by mutagens.

Question 14

What are spontaneous mutations?

Answer 14

They are random errors in meiosis or mitosis.

Question 15

What are the 4 classifications of mutations?

Answer 15

1. Cause of the mutation.
2. Heritability of the mutation.
3. Effect of mutations.
4. Extent of the mutation.

Question 16

What do you talk about in terms of the cause of a mutation?

Answer 16

Whether its induced or sponatanous.

Question 17

What do you talk about in terms of the heritability of a mutation?

Answer 17

Whether it is a somatic or germline mutation.

Question 18

What do you talk about in terms of the effect of a mutation?

Answer 18

Whether it is a missense, nonsense, neutral or silent mutation.

Question 19

Describe somatic mutations.

Answer 19

These mutations cannot be passed into offspring. Only tissues derived from the mutated cell are affected.

Question 20

What is an example of somatic mutations?

Answer 20

Cancer.

Question 21

Describe germline mutations.

Answer 21

Occur in gametes and can be passed onto offspring. Every cell in the entire organsim can be affected.

Question 22

What is an example of germline mutations?

Answer 22

PKU preventing the breakdown of the amino acid phenylalanine.

Question 23

What is a point mutation?

Answer 23

Are changes in a single base pair usually during DNA replication.

Question 24

What are the 4 types of point mutations?

Answer 24

1. Missense
2. Nonsense
3. Neutral
4. SIlent

Question 25

What are missense mutations?

Answer 25

Cause a change in the amino acid and therefore the protein.

Question 26

What are nonsense mutations?

Answer 26

Change in the base sequence to code for a stop codon. This means the synthesis of the protein will stop, so a shorter protein will be produced that will not fulfil its function.

Question 27

What are neutral mutations?

Answer 27

Cause a change in the amino acid but it is of the same type which does not change the structure of the protein and its function.

Question 28

What are silent mutations?

Answer 28

Does not cause a change in the amino acid and therefore the protein is produced.

Question 29

What causes point mutations?

Answer 29

Due to nucleotides being -
1. Inserted - a new nucleotide is added.
2. Deleted - a nucleotide is removed from the DNA strands.
3. Substituted - An existing nucleotide is replaced with another one.

Question 30

What causes frameshift mutations?

Answer 30

Insertions and deletions.

Question 31

What are frameshift mutations?

Answer 31

Occur when a base is inserted or deleted and this changes the reading frame of DNA codons.

Question 32

What causes missense, nonsense, neutral and silent mutations?

Answer 32

Substitutions.

Question 33

What causes chromosomal mutations?

Answer 33

1. Errors during mitosis, meiosis or fertilisation.
2. Mutagens.

Question 34

What are the 4 types of chromosomal mutations?

Answer 34

1. Duplication.
2. Deletion.
3. Inversion.
4. Translocation.

Question 35

What is duplication?

Answer 35

A section of chromosomes occur twice.

Question 36

What is a deletion?

Answer 36

A section of DNA is removed.

Question 37

What is an inversion?

Answer 37

A break in the chromosome occurs and then is reattached the wrong way.

Question 38

What is translocation?

Answer 38

Part of the chromosome breaks off and reattaches to the wrong chromosome.

Question 39

What is non-disjunction?

Answer 39

During meiosis a chromosome pair does not separate and so one daughter cell has an extra chromosome and one daughter cell has one less than the normal number.

Question 40

What is non-disjunction also referred to as?

Answer 40

Aneuploidy.