PATTERNS OF INHERITANCE (4)

Question 1

genotype

Answer 1

specific genes for a particular trait (must be written in symbols)

Question 2

dominant gene

Answer 2

will be expressed and will mask the recessive gene (Bb Tt Ao Bo Ff)

Question 3

recessive gene

Answer 3

only shows up when homozygous recessive (bb tt oo ff)

Question 4

alleles

Answer 4

genes for contrasting traits (Bb Tt Ao Bo)

Question 5

homozygous

Answer 5

identical genes in a pair (bb/ BB)

Question 6

heterozygous

Answer 6

different genes in a pair (Bb/ Ao)

Question 7

phenotype

Answer 7

outward appearance of the offspring (written out in words)

• Bb: brown eyes
• Tt: tongue roller
• Ao: type A blood
• Ff: freckles
• bb: blue eye color
• tt: non tongue roller
• oo: type O blood
• ff: fair skin color

Question 8

punnett square

Answer 8

• are the use of a grid to diagram crosses between individuals by using the possible parental gametes
• these allow one to determine the probability that an offspring will have a particular genotype and phenotype

Question 9

monohybrid cross

Answer 9

an experimental cross in which parents are identically heterozygous at 1 gene pair
(Aa x Aa)

Question 10

multifactoral trait

Answer 10

a polygenic trait that is particularly influenced by the environment

• skin color influenced by sun exposure
• height effected by nutrition

Question 11

incomplete dominance

Answer 11

occurs when the heterozygote is intermediate between the two homozygotes

• CC x SS= CS
• curly hair x straight hair = wavy hair

Question 12

codominance

Answer 12

occurs when alleles are equally expressed in heterozygote

• AA x BB = AB
• type A blood x type B blood= type AB blood

Question 13

sex linked traits

Answer 13

traits controlled by genes on the sex chromosomes

• x-linked are carried on the X chromosome
• y linked are carried on the Y chromosome

Question 14

duchenne muscular dystrophy

Answer 14

is characterized by wasting of muscles and death by age 20

Question 15

fragile X syndrome

Answer 15

is the most common cause of inherited mental impairment

Question 16

hemphilia

Answer 16

is characterized by the absence of particular clotting factors; blood clots very slowly or not at all

Question 17

tay-sachs disease

Answer 17

lack of enzyme that breaks down fatty acid proteins in lysosomes results in accumulation

Question 18

cysitc fibrosis

Answer 18

Cl- ions do not pass normally thru a cell membrane, resulting in thick mucus in lungs and other places, often causing infections

Question 19

sickle-cell disease

Answer 19

red blood cells are sickle shaped rather than biconcave, resulting in clogged blood vessels

Question 20

marfan syndrome

Answer 20

defect in the production of the elastic connective tissue protein fibrillan; results in dislocated lens, long limbs and fingers, caved in chest, and weak wall of aorta

Question 21

huntington disease

Answer 21

huntington protein has too many gluatamine amino acids, leading to the progressive degeneration of brain cells

Question 22

polypeptide

Answer 22

many protein