Genetics Exam

Question 1

3 Principles of Mendel

Answer 1

Dominance, Segregation, Independent Assortment

Question 2

Dominance

Answer 2

One gene may prevent/overpower another gene

Question 3

Segregation

Answer 3

The 2 alleles for a character segregate(separate) during the formation of gametes, so that each gamete carries only one allele for each character

Question 4

Independent Assortment

Answer 4

During gamete formation in a F1 cross, a particular allele for one character can be paired with either allele of another character.

The alleles for different genes ares sorted into the gametes independently of one another

Question 5

Mendel

Answer 5

Father of Genetics

A monk who studied pea plants

Question 6

P/F1 generations

Answer 6

P= parent generation, purebred
F1= first filial, all dominant color

Question 7

Cross Fertilization

Answer 7

or cross, when the sperm from the pollen of one flower fertilizes the eggs in the flower of a different plant

Question 8

hybrid

Answer 8

heterozygote

Question 9

Allele

Answer 9

Evert trait has different options/variations

Question 10

Test cross

Answer 10

if you have the dominant phenotype then cross with the recessive phenotype the type of offspring

Question 11

True Breed

Answer 11

pure bred, homozygote

Question 12

Probability

Answer 12

the likelihood an event will occur

Question 13

Product Rule

Answer 13

the likelihood of 2 or more events happening together is the product of their individual probabilities

Question 14

Genotype

Answer 14

the genes possessed by an organism

Question 15

Phenotype

Answer 15

the physical appearance of an organism

Question 16

Homozygote

Answer 16

individual with the same 2 genes (purebred)

Question 17

Heterozygote

Answer 17

individual with 2 different genes (hybrid)

Question 18

1 factor/monohybrid punnetts

Answer 18

a pairing in which the parents plants differ in only one character

Question 19

2 factor/dihybrid punnetts

Answer 19

crossing organisms differing in 2 charaters

Question 20

dominant

Answer 20

the gene that can be seen when homozygous or heterozygous (overpowers)

Question 21

recessive

Answer 21

the gene that is only seen when homozygous

Question 22

codominance

Answer 22

when there is not a dominant allele and both alleles code for a protein
-only seen in heterozygote

ex. chicken feathers
Fb Fb= black
Fw Fw= white
FbFw= speckled

Question 23

incomplete dominance

Answer 23

when the dominant gene does not make its proteins fully

ex. snap dragon flowers
RR- red rr- white Rr- pink

Question 24

multiple alleles

Answer 24

situations where only 2 genes control a trait but more than 2 alleles exist for the protein
-seen when there are more than 3 phenotypes

Question 25

Blood types

Answer 25

due to membrane tags

3 alleles: IA, IB, i

Question 26

antigens

Answer 26

An antigen is any substance that causes your immune system to produce antibodies against it.

An antigen may be a foreign substance from the environment such as chemicals, bacteria, viruses, or pollen.

An antigen may also be formed within the body, as with bacterial toxins or tissue cells.

ex. different blood type

Question 27

polygenic

Answer 27

the situation where more than 2 genes on different chromosomes control a trait
-seen when there are many phenotypes

ex.
think height: bone, muscle, hormones
parakeets: pigments

Question 28

Genes and environment

Answer 28

genes turned on by environment
ex.
fur color: arctic fox, siamese cat
hydrangea: when in base soil purple, when in acidic soil red/pink
reptiles

Question 29

nature vs. nurture(twin studies)

Answer 29

Twins are born with similar body structure but their traits can then be influenced by nature.
ex. nutrition influences, height, exercise affects build, and exposure to sunlight darkens skiin

Question 30

albinism

Answer 30

genotype- dominant (ww)

phenotype- lack of skin and hair pigment

Question 31

PKU

Answer 31

genotype- recessive (ww)

lack of enzyme to digest amino acid called phenylalanine

can cause decreased mental abilities if untreated.

needs to avoid carbs & proteins

Question 32

cystic fibrosis

Answer 32

genotype- recessive (ww)
due to parents carriers

phenotype- broken cl channel that results in digestive problems and fluid filled lungs
-death between 30 & 40

Question 33

tay sachs

Answer 33

genotype- recessive (ww)

phenotype- exhibit parakysis, dementia, blindness and early death
caused by the absense of a vital enzyme that breaks lipids in the brain

in the USA approximately one in every 27 Jews is a Tay-Sachs carrier

Question 34

Huntingtons

Answer 34

genotype- Dominant (HH or Hh)
phenotype- degeneration of nerves after age 40

Makes an extra protein

Question 35

polydactyl

Answer 35

genotype: dominant
phenotype: extra toe, etc
- commonly seen in cats

Question 36

sickle cell anemia

Answer 36

symptoms: fatigue, organ damage (spleen), anemia, pain (blood clot)

H=hemoglobin
Normal= Hn Hn
Sick= Hs Hs
Carrier= Hn Hs
-1/2 normal
-Malaria Resistance

Question 37

Familial hypercholesteremia

Answer 37

genotype: recessive

a disorder of high LDL (“bad”) cholesterol that is passed down through families, which means it is inherited.

The condition begins at birth and can cause heart attacks at an early age.

unable to remove lipoprotein cholesterol from blood
-high LDL in blood

symptoms: chest pains, cholesterol deposits in eye