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Science · 2024 · 3 marks
CBSE 2024 · Region 5 · Set 2 · Q30
A plant with violet flowers (VV) was crossed with a plant with white flowers (vv).(a)What colour of flowers was obtained in the plants of $\displaystyle \mathrm{F}_{1}$ generation and why ?(b)Write the percentage of plants with white flowers in $\displaystyle \mathrm{F}_{2}$ generation plants, if $\displaystyle \mathrm{F}_{1}$ plants were self-pollinated. Give reason why this trait was not expressed in $\displaystyle \mathrm{F}_{1}$ generation.(c)In what ratio did we get the plants with (VV) and (Vv) gene combination in the $\displaystyle \mathrm{F}_{2}$ generation?
A plant with violet flowers (VV) was crossed with a plant with white flowers (vv).
(a)
What colour of flowers was obtained in the plants of $\displaystyle \mathrm{F}_{1}$ generation and why ?
(b)
Write the percentage of plants with white flowers in $\displaystyle \mathrm{F}_{2}$ generation plants, if $\displaystyle \mathrm{F}_{1}$ plants were self-pollinated. Give reason why this trait was not expressed in $\displaystyle \mathrm{F}_{1}$ generation.
(c)
In what ratio did we get the plants with (VV) and (Vv) gene combination in the $\displaystyle \mathrm{F}_{2}$ generation?
Marking-scheme solution
(a) Violet flowers Violet colour dominates over white colour of flowers.
(b) $\displaystyle 25$%, It could not express itself in the presence of dominant gene/white colour is a recessive gene.
(c) V V : V v $\displaystyle 1$ : $\displaystyle 2$
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CBSE Class 10 Science past-paper question from the 2024board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.