Ch 6 Classical Genetics

Question 1

Mendel’s first law (of dominance)

Answer 1

when two organisms, both homozygous (pure) for oppopsite traits are crossed, offspring will be hybrid and exhibit dominant trait.

Question 2

mendel’s law of segregation

Answer 2

during the formation of gametes, the two traits carried by parent separate.

Question 3

monohybrid cross

Answer 3

cross between to hybrids for single trait.

Question 4

testcross

Answer 4

way to determine if indiv showing dominant trait is homo dominant or hetero.

Question 5

law of indep assortment

Answer 5

during gamete formation, the genes for one trait are not inherited (impacted) along with genes for another trait.

Question 6

phenotype ratio for dihybrid cross

Answer 6

9:3:3:1

Question 7

incomplete dominance

Answer 7

blending of traits. red and white makes pink for ex

Question 8

codominance

Answer 8

both traits show.

Question 9

multiple alleles

Answer 9

more than two allelic forms of a gene like human blood type

Question 10

polygenic

Answer 10

controlled by several genes like skin/hair color

Question 11

sex linked genes

Answer 11

traits carried only on x chromosome. so females need to inherit on both their x chromosomes. ex: color blindness and hemophilia

Question 12

what do karytopes analyze

Answer 12

size, shape, and number of chromosomes.

Question 13

how many chromosomes do humans have? how many autosomes, how may sex?

Answer 13

46 (23 pairs); 44 aut, 2 sex

Question 14

pedigree

Answer 14

family tree that indicates the phenotype of one trait being studied for every member of a family.

Question 15

mutation

Answer 15

abnormalities in the genes. there are gene and chromosome mutations

Question 16

where do mutations occur and cause cancer?

Answer 16

somatic cells. (body)

Question 17

gene mutations

Answer 17

caused by change in DNA sequence

Question 18

chromosome mutations

Answer 18

can be seen under light microscope. chrom may sustain deletion or addition.

Question 19

nondisjunction

Answer 19

chromosome mutation where homologous chromosomes dont separate in meiosis and an extra is in the gamete. Causes Down syndrome

Question 20

aneuploidy

Answer 20

any abnormal chromosome condition

Question 21

trisomy

Answer 21

chromosome present in triplet. Down syndrome is a trisomy-21

Question 22

which mutations can be visible and which cant

Answer 22

gene mutations are not visible in microscope. chromosomal can be seen in karyotype.