Lecture 4 (Mendelian Genetics and Beyond)

Question 1

blending hypothesis

Answer 1

a genetic material from the two parents blend together

Question 2

particulate hypothesis

Answer 2

parents pass on discrete heritable units (gene)

Question 3

P generation

Answer 3

True breeding parents

Question 4

F1 Generation

Answer 4

Hybrids (determines the dominant allele)

Question 5

F2 Generation

Answer 5

children of hybrids

Question 6

Homozygous

Answer 6

2 of the same allele for a character (PP)

Question 7

Heterozygous

Answer 7

2 different alleles for a gene (Pp)

Question 8

hybrid

Answer 8

heterozygous

Question 9

True Breed

Answer 9

homozygous

Question 10

genotype

Answer 10

what are the alleles

Question 11

phenotype

Answer 11

what is the physical appearance of the individual

Question 12

locus

Answer 12

a specific position on a chromosome where a particular gene is located

Question 13

Understanding dominant vs recessive alleles

Answer 13

instead of there being a specific locus for the recessive allele, there might instead just be the absence of the enzyme that prevents it from making the dominant allele which then results in the recessive allele

Question 14

character

Answer 14

a heritable feature that varies among inviduals

Question 15

trait

Answer 15

each variant of a character (for example different colors)

Question 16

test cross

Answer 16

you mate the mystery individual with a homozygous individual based on the results you figure out the alleles for the mystery individual

Question 17

law of segregation

Answer 17

2 alleles for one gene will separate in gamete formation

Question 18

law of independent assortment

Answer 18

states that one pair of alleles separates independently of another pair of alleles (for a different gene) during gamete formation

Question 19

the multiplication rule

Answer 19

use when you have one individual and want to figure out the chances of multiple events

Question 20

the addition rule

Answer 20

add fractions together when you want to know the chance of any number of separate events occurring in one individual

Question 21

dominant allele

Answer 21

usually makes a functional protein

Question 22

recessive allele

Answer 22

usually does not make a functional protein

Question 23

complete dominance

Answer 23

occurs when the phenotypes of the heterozygote and the dominant homozygote are identical (Ex: both Pp and PP produce a purple color)

Question 24

Incomplete dominance

Answer 24

the phenotype of the heterozygotes is somewhere between the phenotypes of 2 parental variants (think blending hypothesis)

Question 25

codominance

Answer 25

2 dominant alleles affect the heterozygote in separate distinguishable ways (for example: blood)

Question 26

pleiotropy

Answer 26

most genes have multiple phenotypic effects

Question 27

Sickle cell disorder

Answer 27

recessive disorder
abnormal RBC shape
cause damage to spleen, respiratory problems, chest pain, fatigue, pale skin, increased chance of infections, stroke, death

Question 28

PKU (Phenylketonuria)

Answer 28

recessive disorder
inability to break down phenylalanine
can cause intellectual disabilities, seizures, fair skin, musty odor, mood disorders, ADHD

Question 29

Cystic Fibrosis

Answer 29

recessive disorder
inability to transport Cl- ions outside the cell
causes build up of mucus in lungs, blocked pancreatic and bile ducts, infections in chest and sinuses, problems absorbing nutrients from food, infertility

Question 30

albinism

Answer 30

recessive disorder
inability to produce a pigment named melanin
causes vision problems, and usually a lack of skin pigmentation

Question 31

huntington’s disease

Answer 31

dominant disorder
a misshapen protein builds up in brain
causes lack or coordination, dementia, heart disease, seizures, depression

Question 32

achondroplasia

Answer 32

dominant disorder
a misshapen protein involved in repressing bone growth that is always active
dwarfism with short arms and legs, a large head, a normal sized torso, frequent ear infections, breathing problems

Question 33

polydactyly

Answer 33

extra fingers/toes

KEEP IN MIND THAT DOMINANT ALLELES ARENT NECESSARILY MORE COMMON THAN RECESSIVE ALLELES

Question 34

haplosufficiency

Answer 34

having only one normally functioning allele is enough to be completely healthy

Question 35

haploinsuffiency

Answer 35

having only one normally functioning allele isnt enough to be healthy

Question 36

epistasis

Answer 36

a gene at one locus alters phenotypic expression of a gene at a second locus

Question 37

polygenic inheritance

Answer 37

an additive effect of 2 or more genes on a single phenotype

Question 38

quantitative characters

Answer 38

those that vary in population along a continuum

Question 39

multifactorial characters

Answer 39

have polygenic and environmental influences on phenotypes

Question 40

how does temperature affect the phenotype

Answer 40

a sensitive allele whose product is functional only at certain temperatures

in some animals, temperature determines the sex of the offspring

Question 41

how does environment impact phenotypes?

Answer 41

a child’s environment or access to nutrients and proper education could affect their intelligence or height (nutrients)

hydrangeas color changes based on the soil acidity

Himalayan rabbits the color of their fur changes based on cold temperatures. present in all the body but turned on only where it is cold (nose, ear, feet)