Mendelian Inheritance I

Question 1

describe the blending hypothesis

Answer 1

genetic material from 2 parents blend together to form intermediate, ex. blue mom and a yellow dad produces a green offspring

Question 2

what 2 phenomenons contradicted the blending hypothesis?

Answer 2

uniformity is not observed and there is a reappearance of a trait “lost” in F1 that reappears in F2 (grandchildren) that skipped a generation in F1

Question 3

what were the benefits of using peas for experiment?

Answer 3

short generation time, many varieties of characters (color, shape, etc), large number of offspring, controllable mating

Question 4

define hybridization

Answer 4

mating 2 contrasting, true-breeding varieties

crossing

Question 5

define true-breeding

Answer 5

homozygous, always produces gametes with same alleles/phenotype

Question 6

What surprise occurred in F1 gen?

Answer 6

recessive trait disappeared

Question 7

what surprise occurred in F2 gen?

Answer 7

recessive trait returned

Question 8

What hypothesis did Mendal propose?

Answer 8

Particulate hypothesis: parents pass on genes

Question 9

what stages could the blending hypothesis be disproven?

Answer 9

F1 and F2

Question 10

What gen did Mendel observe and deduce segregation and independent assortment law?

Answer 10

F2

Question 11

What pattern was observed in the F2?

Answer 11

3:1

Question 12

What is concept 1?

Answer 12

Alternative versions of genes account for variation in inherited characters called alleles
Each gene resides on a locus on a chromosome

Question 13

What is concept 2?

Answer 13

For each character, an organism inherits 2 copies of a gene, one from each parent
Homozygous and heterozygous concepts

Question 14

What is concept 3?

Answer 14

If 2 alleles at a locus differ, dominant one is expressed

Question 15

What is concept 4?

Answer 15

Law of segregation: 2 alleles for a character separate during gamete formation

Question 16

What is a testcross?

Answer 16

Cross unknown with recessive homozygote- if unknown is homozygous, only dominant phenotype in F1. If half dom half rec, unknown is heterozygous

Question 17

What is a dihybrid cross

Answer 17

cross between F1 dihybrids…YrRr x YyRr

determined law of independent assortment

Question 18

define dihybrids

Answer 18

crossing 2 true-breeding parents differing in 2 characters

F1 gen, heterozygous for both characters

Question 19

What is the law of independent assortment?

Answer 19

each pair of alleles separate independently of other pairs of alleles during gamete formation
law applies only to genes on diff chromosomes or far apart on same one