(a) How would you find out whether a given tall garden pea plant is homozygous or heterozygous? Substantiate your answer with the help of Punnett squares.

Question

(a) How would you find out whether a given tall garden pea plant is homozygous or heterozygous? Substantiate your answer with the help of Punnett squares.
(b) Given below are the F2-phenotypic ratios of two independently carried monohybrid crosses:

(i) 1 : 2 : 1

(ii) 3 : 1

Mention what does each ratio suggest.

OR

a) Why did Hershey and Chase use radioactive 32P and 35S in their Experiments? Explain.

(b) Following the experiments conducted by them, write what Conclusion did they arrive at and how.

Philoid · Accepted Answer

a) if we want to find out whether the tall pea plant was homozygous or heterozygous

B) I)1:2:1

Let us take

Red and white flower

AA – red

Aa – white

- F₂ generation

Now the ratio will be 1:2:1

50% of pink flowers

25% of white flowers

25% of red flowers

ii) 3:1

If you let the F1 generation self-fertilize, the next monohybrid cross would be –

Pp × Pp

(Purple) (Purple)

Phenotypes - 3 purple flowers and 1 white flower, 3:1

OR

a) Radioactive 32P contains DNA but not radioactive protein as DNA contains phosphorus

Radioactive 35S contains protein but not DNA as DNA does not contains sulfur

They worked with with viruses that infects bacteria called bacteriophages

They want to know whether it was protein or DNA from the viruses that entered the bacteria

b) The procedure they followed were -

The conclusion was bacteria which was infected had radioactive DNA(DNA was the material that passes virus to the bacteria)