Chapter 29

Question 1

Define: autosome

Answer 1

Chromosomes 1-22, not including the sex chromosome

Question 2

XX and XY chromosomes that determine gender

Answer 2

sex chromosome

Question 3

Genes that occur at same locus (location) on homologous chromosomes

Answer 3

Alleles

Question 4

What is the difference between homozygous and heterozygous?

Answer 4

Homozygous: alleles are same for single trait
Heterozygous: alleles are different for single trait

Question 5

Define: genotype vs phenotype

Answer 5

genotype: genetic makeup
phenotype: physical appearance

Question 6

Huntington’s disease is caused by:

Answer 6

Degeneration of the white brain matter and cerebral cortex

Question 7

Explain the events of crossing over

Answer 7

Chromosomes can break and precisely exchange gene segments with their homologous counterparts

Question 8

Explain the events of random fertilization

Answer 8

Extreme variation due to a combination of crossing over and independent assortment

Question 9

Explain the events of independent assortment

Answer 9

Alleles on different pairs of homologous chromosomes are distributed independently of each other.

Question 10

Traits dictated by dominant alleles include widow’s peaks, ____, and dimples, double-jointed ____, or taste phenylthiocarbamide (PTC) to name a few

Answer 10

freckles; thumbs

Question 11

Heterozygotes are carriers of ____ trait, meaning they do not express trait but can
pass it on to ____

Answer 11

recessive; offspring

Question 12

Most genetic disorders are inherited as simple ____ traits

Answer 12

recessive

Question 13

Define: incomplete dominance

Answer 13

Alleles overlapping instead of one being completely masked, resulting in a phenotype in the heterozygote that is a combination of both traits.

Question 14

What causes sickle-cell anemia?

Answer 14

Abnormal cell shape caused by low iron resulting in low oxygen levels

Question 15

More than 2 alleles on a single gene describes what type of inheritance?

Answer 15

Multiple-Allele Inheritance

Question 16

Codominance is a result of 2 alleles expressed ____

Answer 16

equally

Question 17

Traits determined by genes on the sex chromosomes describes ____ inheritance, and (males/females) have more proteins on their chromosome to help brain function.

Answer 17

sex-linked; females

Question 18

Which type of inheritance results in continuous, or quantitative, phenotypic variation between two extremes and explains many human characteristics?

Answer 18

Polygenic inheritence

Question 19

Examples of polygene traits in humans include:

Answer 19

Skin color, height, metabolic rate, and intelligence.

Question 20

Describe the influence of small RNA on inheritance:

Answer 20

2nd control layer that forms the parallel regulatory system which reduce the expression of particular genes by destruction, inhibition, or silencing of the mRNA

Question 21

Describe the influence of epigenetics on inheritance:

Answer 21

Epigenetic marks determine if translation is possible or silenced, inactivates the X in female embryos, and has a potential disposition to turn cells cancerous

Question 22

Mitchondrial genes are inherited by the ____ because almost the entire ____ is donated to the fertilized egg. Errors in these genes create what type of disorders?

Answer 22

mother; cytoplasm; degenerative muscle or neurological disorders

Question 23

What tool is used to trace a genetic trait through several generations and help predict the future using phenotypic information

Answer 23

Pedigree

Question 24

Blood tests are used to test the ____ gene and can detect unexpressed ____ genes

Answer 24

sickling; recessive

Question 25

What is the most common type of fetal testing, where a wide-bore needle is inserted into the amniotic sac through the mother’s abdominal wall

Answer 25

amniocentesis

Question 26

Describe the procedure: Chorionic villus sampling (CVS)

Answer 26

Suctions off bits of the chorionic villi from the placenta for examination

Question 27

Excessively thick mucus production, impairing the lung and pancreatic functioning

Answer 27

Cystic fibrosis

Question 28

Hemophilia and Duchenne muscular dystrophy are recessive disorders developed through what type of inheritance

Answer 28

sex-linked