Chapter 20 Pt. 2

Question 1

What is a pedigree?

Answer 1

a chart showing the genetic connections between individuals in a family

Question 2

_________ ___________-inheritance of genetic

Answer 2

autosomal dominant

Question 3

_________ __________-genetic disorders caused by recessive alleles on a pair of non-sex chromosomes

Answer 3

autosomal recessive

Question 4

Which type of dominance is this:
a situation in which a heterozygous individual exhibits the trait associated with the dominant allele but not that of the recessive allele

Answer 4

complete dominance

Question 5

Which type of dominance is this:
the expression of a trait in a heterozygous individual is somewhere between the expression of the trait in a homozygous dominant individual and the expression of the trait in a homozygous recessive individual

Answer 5

incomplete dominance

Question 6

Which type of dominance is this:

The inheritance of type AB blood

Answer 6

codominance

Question 7

Which type of dominance is this:

sickle-cell anemia

Answer 7

incomplete dominance

Question 8

What is pleiotropy?

Answer 8

one gene leading to many effects

Question 9

_______ _______- when 3 or more forms of a given gene exist

Answer 9

multiple alleles

Question 10

What is polygenic inheritance?

Answer 10

the involvement of 2 or more genes, often on different chromosomes, in predicting a trait

Question 11

the more genes involved, the smoother the _________ and the greater the extremes of _____ _________

Answer 11

gradations

trait expression

Question 12

Genes that tend to be inherited together are described as being ______

Answer 12

linked

Question 13

True or False: Linked genes usually tend to assort independently

Answer 13

False; Linked genes usually don’t assort independently

Question 14

__-______ ______-most genes on the X chromosome have no corresponding alleles on the Y chromosome

Answer 14

X-linked genes

Question 15

the recessive phenotype of X-linked genes is much more common in which sex?

Answer 15

males

Question 16

True or False: a son cannot inherit an X-linked recessive allele from his father

Answer 16

True

Question 17

True or False: a daughter, cannot inherit an X-linked recessive alley from either parent

Answer 17

False; a daughter can inherit an X-linked recessive alley from either parent

Question 18

What are the disorders caused by X-linked recessive alleles?

Answer 18

red-green color blindness
two forms of hemophilia
Duchenne muscular dystrophy

Question 19

What is the cause of breakage among chromosomes?

Answer 19

certain chemicals, radiation, or viruses

Question 20

What is the difference between deletion and duplication?

Answer 20

deletion-the loss of a piece of chromosome

duplication- the addition of a piece of chromosome

Question 21

What is the most common type of deletion?

Answer 21

occurs when the tip of a chromosome breaks off and then, during cell division, doesn’t move into the same daughter cell as the rest of the chromosome

Question 22

What happens when you delete more than a few genes on an autosome?

Answer 22

is usually lethal

Question 23

The loss of small regions, due to deletion, can cause ________

Answer 23

disorders

Question 24

Cri-du-chat syndrome is an example of _______

Answer 24

deletion

Question 25

___-__-___ ________ is an example of deletion

Answer 25

Cri-du-chat syndrome

Question 26

What is Cri-du-chat syndrome?

Answer 26

“cry of the cat”; caused by the loss of a small region near the tip of chromosome 5

Question 27

What is Fragile X Syndrome?

Answer 27

an abnormally long sequence of repeats caused by duplication makes the X chromosome fragile and easily broken

Question 28

_______ __ ________ is an example of duplication

Answer 28

Fragile X Syndrome

Question 29

Fragile X Syndrome is an example of _________

Answer 29

duplication

Question 30

______ __ ________ is the most common form of inherited mental impairment

Answer 30

Fragile X Syndrome

Question 31

True or False: a small deletion is less harmful than a duplication of comparable size

Answer 31

False; a small duplication is less harmful than a deletion of comparable size

Question 32

What are the two procedures available for diagnosing genetic problems in the fetus?

Answer 32

(1) amniocentesis

2) chorionic villi sampling (CVS

Question 33

____________- a needle is inserted through the lower abdomen into the uterus, and a small amount of amniotic fluid is withdrawn

Answer 33

amniocentesis

Question 34

________ ____ ________ (____)- removes and analyzes a small amount of tissue containing chorionic villi, the small, fingerlike projections of the part of the placenta called the chorion

Answer 34

chorionic villi sampling (CVS)