Final- 15

Question 1

Chromosome theory of inheritance

Answer 1

Mendellian genes have specific loci on chromosomes

Chromosome undergo segregation and independent assortment

Question 2

Why did Thomas Hunt Morgan use fruit flies

Answer 2

They produce a lot of offspring
They reproduce quickly
They only have four pairs of chromosomes

Question 3

Wild type

Answer 3

Most typical phenotype (only one)

Question 4

Mutant

Answer 4

All other phenotypes that are not the wild type

Question 5

Where is the sex linked gene located

Answer 5

On the sex chromosome, unrelated to sex

Question 6

Most sex linked traits are on the ___ chromosome

Answer 6

X

Question 7

Who is affected more by X linked traits, male or female

Answer 7

Male. Only one X needed (hemizygous)

X always comes from the mother

Question 8

How many copies of the allele do females need to be affected

Answer 8

2 (homozygous)

Question 9

Examples of sex linked genes

Answer 9

Color blindness, Duchenne muscular dysthrophy, hemophilia

Question 10

What is a Barr body

Answer 10

When one X chromosome is innactivated in females (Calico cats)

Question 11

How do offspring get a unqiue combination of traits different from each of the parents

Answer 11

Genetic recombination events

Question 12

What drives natural selection

Answer 12

new combinations of alleles

Question 13

What produces genetic recombination of unlinked genes

Answer 13

Independent assortment of chromosomes

Question 14

What can damage the chromosomes in major ways or alter their number in the cell

Answer 14

Physical and chemical disturbances, as well as errors in meiosis

Question 15

What can tolerate genetic defects well

Answer 15

Plants

Question 16

What leads to abnormal chromosome number

Answer 16

Nondisjunction

Question 17

Nondisjunction

Answer 17

may occur if members of a pair of homologous chromosomes do not separate properly during meiosis I or sister chromatids fail to separate during meiosis II (one gamete receives 2 of the same type of chromosome, other receives none)

Question 18

Aneuploidy (types)

Answer 18

Trisomic

Monosomic

Question 19

Aneuploidy deinition

Answer 19

Fertilization of gametes where nondisjunction occurred

Question 20

Trisomic

Answer 20

cells have three copies of a particular chromosome type and have 2n+1 chromosomes

Question 21

Monosomic

Answer 21

cells have only one copy of a particular chromosome type and have 2n-1 chromosomes

Question 22

Polyploid

Answer 22

Organisms with more than two complete sets of chromosomes

Common in plants

Question 23

What can lead to changes in the chromosome sturcture

Answer 23

Breakage of the chromosome

Question 24

Four types of changes in the chromosome structure

Answer 24

• Deletion
• Duplication
• Inversion
• Translocation

Question 25

Deletion

Answer 25

Occurs when a chromosome fragment is lost. The chromosome is missing certain genes

Question 26

Duplication

Answer 26

Occurs when a fragment become attached as an extra segment to a sister chromatid

• Alternatively a detached fragment may attach to a nonsister chromatid of a homologous chromosome
• In this case, the dupicated segments will not be identical if the homologs carry different alleles

Question 27

Inversion

Answer 27

Occurs when a chromosomal fragment reattaches to the original chromosome, but in reverse orientation

Question 28

Translocation

Answer 28

A chromosomal fragment joins a homologous chromosome

Moves a segment from one chromosome to another

Question 29

What disorder is due to a chromosome alteration

Answer 29

Downs syndrome- aneuploid condition, 3 copies of 21

Question 30

Cri du chat results from ____

Answer 30

specific deletion in chromosome 5

Question 31

What can cause leukemia (CML)

Answer 31

chromosomal translocations