Question

one student want to cross pure tall plant (TT) with dwarf (TT) plant , what would be the F1 and F2 generations? explain​

Answer 1

Answer:

Hope my running notes helps u...

Answer 2

Refer the above attachment

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Explanation:

1) When we cross between two pure

homozygous parents differing in a

single pair of contrasting character we

call it as monohybrid cross

2) Here in TT × tt we can see parents are

homozygous and differing in only one

contrasting character that is Height. Hence it is monohybrid cross

3) When parents are pure lines or

homozygous we call that breeding as

true breeding

4) During gamete formation factors

separate and only one enters in each

gamete. So pure parents produce only

one type of gamete

5) Phenotype of TT and Tt are same that

is tall while in genotype if the gamete

type differs the ratio also differs

6) For example: When we crossed in F2

generation we got TT, Tt, Tt, tt. Here we

can see phenotypes are tall and dwarf

but genotypes are TT, Tt, tt. There are

three different genotypes

7) Mendel used to performed this cross in

pea plants. In F2 generation there was

formation of two type of gametes in

equal proportion that is 50% of male

gametes with capital T and 50% with

small t while 50% of female gametes

with capital T and 50% with small t

8) Recessive character will not appear in

cross between pure line as it follows law

of dominance

Extra information:

# To find number of gametes use

2ⁿ that is 2 raise to n where n is number

of heterozygous conditions

For example

1. In TT × tt

There is no heterozygous conditions

so, n= 0

While solving,

2^0 = 1

Number of gametes formed is 1

2. In Tt × Tt

n = 2 heterozygous conditions

While solving,

2² = 4

Number of gametes formed is 4