Mendelian Transmission of Alleles Flashcards Preview

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Flashcards in Mendelian Transmission of Alleles Deck (26)
1

if we know the genotypes of two parents we can...

predict the genotype of their offspring

2

a cross btw 2 homozygotes always gives...

a heterozygote

3

a cross between diploids where all 4 alleles in the parents are different...

4 possible combinations all with equal frequencies

4

a cross of 2 heterozygoes Aa x Aa genotypes

genotype AA 1/4

Aa 1/2

aa 1/4

ratio is 1:2:1

5

a cross of 2 heterozygotes Aa x Aa phenotypes

AA + Aa 3/4

aa 1/4

ratio is 3:1

6

mendelian ratio

a cross btw 2 heterozygoes yields ratios

genotypic: 1:2:1

phenotypic: 3:1

7

mendel worked with ___ which are normally ____

peas, self-fertilizing

8

how to cross peas

cut open flower before sex parts are mature

transfer pollen from one flower to another

put pollen on the pistil (gateway to female gamete)

9

pollen is the ___ gamete

male

10

mendel's question

what happens when you cross two distinct true-breeding strains?

11

mendel first...

crossed pairs of strains with distinct alternative traits

purple x white flowers

12

first thing mendel noticed

in every cross, one was dominant

13

mendel secondly...

allowed hybrids to self-fertilize

14

mendel noticed secondly...

offspring of 2nd generation showed both traits again

ratio of 3:1 dominant:recssive

15

particulate inheritance

information is copied and passed on in some physical form

16

diploidy

individuals have 2 copies of the info for each trait

one from each parent

17

dominance/recessivity

some copies only produce their effect when the other copy is absent

18

random segregation

2 copies for each trait are passed on independently and randomly

19

mendel's 1st law

segregation

alleles of genes are copied and passed on independently through haploid and diploid phases

20

phenotypic ratio of 3:1 results from...

cross of 2 heterozygotes if there is dominance

21

phenotypic ratio of 1:1 results from...

cross of a heterozygote with a recessive homozygote

22

phenotypic ratio of 2:1 results from...

crossed heterozygotes if a dominant allele is recessive lethal

23

in offspring with a 3:1 phenotypic ratio....

2/3 of the dominant types are carriers (heterozygotes)

24

genotypic ratio of 1:2:1 at conception...

result from a cross of 2 heterozygotes

25

achondroplastic dwarfism

cross heterozygotes Dd x Dd

genotypic ratio at conception 1:2:1

phenotypic ratio at birth 2:1 (DD babies die)

dd gives normal height

26

mexican hairless dogs

all are heterozygotes

cross Hh x Hh

genotypic ratio at conception 1:2:1

phenotypic ratio at birth 2:1 (HH babies die)

hh gives dog with hair