ch 13

Question 1

The theory stating that hereditary traits are carried on chromosomes.

Answer 1

chromosomal theory of inheritance

Question 1

heritable alterations in genetic material

Answer 1

mutations

Question 2

A chromosome that is related to sex; in humans, the sex chromosomes are the X and Y chromosomes.

Answer 2

sex chromosomes

Question 3

A trait determined by a gene carried on the X chromosome and absent on the Y chromosome.

Answer 3

sex-linked

Question 4

Any eukaryotic chromosome that is not a sex chromosome; autosomes are present in the same number and kind in both males and females of the species.

Answer 4

autosomes

Question 5

A phenomenon by which the expression of genes carried on sex chromosomes is kept the same in males and females, despite a different number of sex chromosomes. In mammals, inactivation of one of the X chromosomes in female cells accomplishes dosage compensation.

Answer 5

dosage compensation

Question 6

A deeply staining structure, seen in the interphase nucleus of a cell of an individual with more than one X chromosome, that is a condensed and inactivated X. Only one X remains active in each cell after early embryogenesis.

Answer 6

barr body

Question 7

individuals who have lost one copy of an autosome

Answer 7

monosomic

Question 8

individuals who have gained one copy of an autosome

Answer 8

trisomic

Question 9

The failure of homologues or sister chromatids to separate during mitosis or meiosis, resulting in an aneuploid cell or gamete.

Answer 9

nondisjunction

Question 10

The condition in an organism whose cells have lost or gained a chromosome; Down syndrome, which results from an extra copy of human chromosome 21, is an example of aneuploidy in humans.

Answer 10

aneuploidy

Question 11

Genetic disease usually caused by presence of an additional chromosome 21 (trisomy 21). This can also be due to a translocation of material from chromosome 21 to another chromosome. The translocated chromosome combined with two normal copies of chromosome 21 produces the same effect as trisomy. The syndrome is characterized by growth reductions, characteristic facial structure, and mild to moderate intellectual disability.

Answer 11

down syndrome

Question 12

The process of evaluating the risk of genetic defects occurring in offspring, testing for these defects in unborn children, and providing the parents with information about these risks and conditions.

Answer 12

genetic counseling