(SBI4U1) Gene Mutations

Question 1

Define a mutation

Answer 1

A permanent change in the genetic material

Question 2

Only ____ ____ _________ are passed on to offspring

Answer 2

Germ cell mutations

Question 3

What are germ cell mutations?

Answer 3

Mutations in reproductive cells

Question 4

_______ ____ _________ are not passed on to future generations, but are passed on to daughter cells during mitosis

Answer 4

Somatic cell mutations

Question 5

Define mutagens

Answer 5

Causes of mutations

Question 6

What are examples of physical mutagens? (2)

Answer 6

High energy radiation (x-rays, gamma rays)
UV radiation (sun light)

Question 7

What are examples of chemical mutagens?

Answer 7

Carcinogens (molecule that can enter the nucleus and induce mutations)

Question 8

What are the two main types of mutations?

Answer 8

Frameshift mutations

Base substitution mutations

Question 9

What are the two types of frameshift mutations?

Answer 9

Insertion

Deletion

Question 10

What does insertion mutation do?

Answer 10

Causes reading frame to shift to the right

Question 11

What does deletion mutations do?

Answer 11

Causes reading frame to shift to the left

Question 12

Frameshift mutations produce a ___-__________ ___________ (because codon sequences change enough to change amino acid sequence)

Answer 12

Non-functional polypeptide

Question 13

What are the three types of base substitution mutations?

Answer 13

Missense
Silent
Nonsense

Question 14

What is a missense mutation?

Answer 14

Occur when a substitution of an incorrect nitrogen base leads to the codon coding for the wrong amino acid

Question 15

What is a silent mutation?

Answer 15

A base in a codon changes, but the same amino acid product is made

Question 16

What is a nonsense mutation?

Answer 16

A base substitution creates a new stop codon

Question 17

True or false:

Missense mutations can make the protein dysfunctional

Answer 17

True, as the code will code for a different amino acid

Question 18

True or false:

Silent mutations have small effects on the polypeptide product that are not noticeable

Answer 18

False, silent mutations have no effect on polypeptide product because of the redundancy of the genetic code

Question 19

True or false:

Nonsense mutations can have serious effects on the cell

Answer 19

True, as it produces shortened, nonfunctional polypeptides