Chapter 12

Question 1

recessive disorder

Answer 1

a medical condition that will not occur when an organism possesses a single functional allele for a given trait.

Question 2

autosomal recessive disorder

Answer 2

a recessive dysfunction caused by a faulty allele on an autosome (non-sex chromosome)

Question 3

carrier

Answer 3

a person who does not suffer from a recessive genetic debilitation, but who carries an allele for the condition that can be passed along to offspring.

Question 4

aneuploidy

Answer 4

A condition in which an individual organism has either more or fewer chromosomes than is normally found in its species’ full set

Question 5

autosomal dominant disorder

Answer 5

a genetic disorder caused by a single faulty allele located on an autosomal (non-sex chromosome)

Question 6

deletion

Answer 6

a chromosomal condition in which a piece of a chromosome has been lost. Occurs when a chromosomal fragment that breaks off does not rejoin any chromosomes.

Question 7

dominant disorder

Answer 7

genetic conditions in which a single faulty allele can cause damage, even when a second, functional allele exists.

Question 8

Down syndrome

Answer 8

a disorder in humans in which affected individuals usually have three copies of chromosome 21 rather than the standard two. Individuals with this syndrome have short stature, shortened life span, and low IQ.

Question 9

inversion

Answer 9

a chromosomal abnormality that comes about when a chromosomal fragment that rejoins a chromosome does so with an inverted orientation.

Question 10

nondisjunction

Answer 10

a failure of homologous chromosomes or sister chromatids to separate during cell division.

Question 11

pedigree

Answer 11

a familial history of genetically transmissible conditions; generally takes the form of a diagram.

Question 12

polyploidy

Answer 12

a form of sympatric speciation in which one or more sets of chromosomes are added to the genome of an organism. Human beings cannot survive in a polyploid state, but many plants flourish in it. Polyploids is a means by which speciation can occur (most often in plants) in a single generation

Question 13

translocation

Answer 13

the swapping of fragments by nonhomologous chromosomes, resulting in gene sequences that are out of order on both chromosomes.

Question 14

Example of recessive disorder

Answer 14

reg-green color blindness

Question 15

Example of a autosomal dominant disorder

Answer 15

Huntington disease

Question 16

Example of a autosomal recessive disorder

Answer 16

Sickle-cell anemia