Mutations

Question 1

What Are Mutations?
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•
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Answer 1

•Changes in the nucleotide sequence of DNA
•May occur in somatic cells (aren’t passed to offspring)
•May occur in gametes (eggs & sperm) and be passed to offspring

Question 2

•Mutations happen ______
•Almost all mutations are _______
•_______&_____ radiation cause mutations
•Many mutations are repaired by ________

Answer 2

• regularly
• neutral
• Chemicals & UV
• enzymes

Question 3

•Some type of skin cancers and leukemia result from ___________
•Some mutations may improve an organism’s survival (beneficial)

Answer 3

somatic mutations

Question 4

A _________ is a DNA molecule that is tightly coiled around proteins called ________, which support its structure, to form a _______ structures.

Answer 4

chromosome
histones
thread-like

Question 5

Parts of a chromosome

Answer 5

p arm
centromere
q arm
CHROMOSOME

histone proteins
DNA

Question 6

5 types of chromosome mutations

Answer 6

Deletion
Inversion
Translocation
Nondisjunction
Duplication

Question 7

_____________

•Due to ______
•A piece of a chromosome is lost

Answer 7

DEPLETION

breakage

Question 8

_______________

•Chromosome segment ______ •Segment flips around _______
•Segment reattaches

Answer 8

INVERSION

breaks off
backwards

Question 9

DUPLICATION

•Occurs when a ________ is repeated

Answer 9

gene sequence

Question 10

____________

•Involves two chromosomes that are NOT homologous
•Part of one chromosome is transferred to another chromosome

Answer 10

Translocation

Question 11

Failure of chromosomes to separate during meiosis

Answer 11

Nondisjunction

Question 12

Causes gamete to have too many or too few chromosomes

Answer 12

Nondisjunction

Question 13

Disorders in nondisjunction

Answer 13

Down syndrome
Turner syndrome
Klinefelter’s syndrome

Question 14

three 21st chromosomes

Answer 14

Down syndrome

Question 15

single X chromosome

Answer 15

Turner syndrome

Question 16

XXY chromosomes

Answer 16

Klinefelter’s syndrome

Question 17

Down syndrome is also known as _______

Answer 17

trisomy 21

Question 18

• is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21.

• It is typically associated with physical growth delays, characteristic facial features and mild to moderate intellectual disability.

Answer 18

Down syndrome

Question 19

A condition that affects only females, results when one of the X chromosomes (sex chromosomes) is missing or partially missing.

Answer 19

Turner syndrome

Question 20

It can cause a variety of medical and developmental problems, including short height, failure of the ovaries to develop and heart defects.

Answer 20

Turner syndrome

Question 21

It occurs when a boy is born with one or more extra X chromosomes

Answer 21

Klinefelter’s syndrome

Question 22

Having extra X chromosomes can cause a male to have some physical traits unusual for males such as weaker muscles, greater height, poor coordination, less body hair, and sterility

Answer 22

Klinefelter’s syndrome

Question 23

Process of nondisjunction

Answer 23

1. Meiosis l starts normally. Tetrads line up in the middle of cell.
2. Then one set of homologs does not separate (=nondisjunction)
3. Meiosis ll occurs normally
4. All gametes have an abnormal number of chromosomes - eighter one too many or one too few.

Question 24

Change in the nucleotide sequence of DNA

Answer 24

Mutation

Question 25

Gene Mutation

Answer 25

•Change in the nucleotide sequence of a gene
•May only involve a single nucleotide
•May be due to copying errors, chemicals, viruses, etc.

Question 26

Types of Gene Mutations
Include:

Answer 26

–Point Mutations
–Substitutions
–Insertions
–Deletions
–Frameshift

Question 27

•Change of a single nucleotide

Answer 27

Point mutation

Question 28

•Includes the deletion, insertion, or substitution of ONE nucleotide in a gene

Answer 28

Point mutation

Question 29

• _______ is the result of one nucleotide substitution
•Occurs in the _________

Answer 29

• Sickle Cell disease
• hemoglobin gene

Question 30

In this mutation, the proteins built incorrectly

Answer 30

Frameshift Mutation

Question 31

•Inserting or deleting one or more nucleotides
•Changes the “_________” like changing a sentence

Answer 31

Frameshift Mutation
reading frame

Question 32

It is a mutation that exchanges one base for another

(i.e., a change in a single “chemical letter” such as switching an A to a G)

Answer 32

Substitution mutation

Question 33

The addition of one or more nucleotide base pairs into a DNA sequence

Answer 33

Insertion mutation

Question 34

A part of a chromosome or a sequence of DNA is lost during DNA replication

Any number of nucleotides can be deleted, from a single base to an entire piece of chromosome

Answer 34

Deletion mutation