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प्रश्न
Mendel crossed pea plants with two pairs of contrasting characters.
| RRYY | × |
rryy |
| Round, Yellow | Wrinkled, Green |
He observed 4 types of combinations in F2 generation. Which of the combinations were new? Write the conclusion drawn by this experiment.
उत्तर
A Mendelian experiment will find that some F2 progeny are tall plants with round seeds, and some were short plants with wrinkled seeds. However, there would also be some F2 progeny that showed new combinations. Some would be tall but have wrinkled seeds, while others would be short but have round seeds. You can see how new combinations of traits are formed in F2 offspring when factors controlling for seed shape and seed colour recombine to form a zygote, leading to the form of F2 offspring. Thus, the tall/short trait and the round seed/wrinkled seed trait are independently inherited.
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संबंधित प्रश्न
It it an example of monohybrid cross or dihybrid cross?
A trait in an organism is influenced by ______
A person first crossed pure-bred pea plants having round-yellow seeds with pure-bred pea plants having wrinkled-green seeds and found that only A-B type of seeds were produced in the F1 generation. When F1generation pea plants having A-B type of seeds were cross-bred by self-pollination, then in addition to the original round-yellow and wrinkled-green seeds, two new varieties A-D and C-B type of seeds were also obtained.
(a) What are A-B type of seeds?
(b) State whether A and B are dominant traits or recessive traits.
(c) What are A-D type of seeds?
(d) What are C-B type of seeds?
(c) Out of A-B and A-D types of seeds, which one will be produced in (i) minimum numbers, and (ii) maximum numbers, in the F2 generation?
Pure-bred round-yellow pea seeds have genotype RRYY and the pure-bred wrinkled-green pea seeds have genotype rryy. Keeping this in mind, write the phenotypes of the following genotypes of hybrid pea seeds :
(a) Rryy
(b) rrYy
(c) rrYY
(d) RrYy
(e) RRyy
The farmers have been cultivating a food plant X for over two thousand years and have produced as many as five entirely different looking vegetables A, B, C, D and E from it.
(a) What could the plant X be?
(b) What are A, B, C, D and E?
(c) What is the process of evolution involved in this example known as?
Answer the following question.
Why are the traits acquired during the life-time-of-an individual not inherited? Explain.
Write advantages of science of heredity.
What will be the number of chromosomes present in each gamete produced by the plants if the palisade cells of a species of the plant contain 28 chromosomes in all?
A cross between a tall plant (TT) and short pea plant (tt) resulted in progeny that were all tall plants because
If a round, green seeded pea plant (RR yy) is crossed with wrinkled, yellow seeded pea plant, (rr YY) the seeds produced in F1 generation are
