MONOHYBRID INHERITANCE Flashcards
1
Q
monohybrid inheritance
A
inheritance of a single gene i.e height/colour
2
Q
Mendel’s experiments: why did he use peas? (4)
A
- easy to grow
- self & cross fertilise
- make flowers & fruit in the same year
- large number of seeds produced per cross
3
Q
Mendel’s experiments: why were his choice of characteristics good? (3)
A
- controlled by single genes
- unlinked (genes on different chromosomes)
- clear-cut, easy to differentiate between
4
Q
Steps of a genetic cross (4)
A
- Parental phenotype i.e blue
- parental genotype i.e aB
- gametes passed on (in a circle)
- punnet square
5
Q
what does a test cross/back cross do? (monohybrid)
A
- shows whether a trait is determined by one or two allelles
6
Q
how do you do a test cross?
A
- breed unknown with homozygous recessive
7
Q
co-dominance explanation (3)
A
- both allelles expressed individually
- combination of both characteristics
- i.e AB have both A & B antigens
- written as I^A or I^B or I^A I^ B
8
Q
incomplete dominance explanation (2)
A
- rather than traits of both, it is the middle ground between the two
- i.e red flower bred with white produces pink flowers
- written as C^R or C^W or C^R C^W
9
Q
Mendel’s law of segregation
A
An organism’s characteristics are determined by allelles, each parent contributes one
10
Q
Monohybrid Mendelian ratio
A
1:3 (when unlinked)
11
Q
Independent assortment (2)
A
- Occurs during metaphase I and II
- parental chromosomes line up randomly along equator
12
Q
Monohybrid punnet square
A
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