Advertisements
Advertisements
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.
APPEARS IN
संबंधित प्रश्न
Name the scientist who gave the laws of inheritance.
What is the genotype of (i) dwarf plants, and (ii) tall plants, whose parental cross always produces tall offspring?
What sizes of plants are produced if both parents have genes Tt?
Why did Mendel choose pea plants for conducting his experiments on inheritance?
State Mendel's second law of inheritance.
When two parents are crossed, the offspring are referred to as :
recessives
test cross
F1 generation
F2 generation
The following results were obtained by a scientist who crossed the F1 generation of pure-breeding parents for round and wrinkled seeds.
| Dominant trait | Recessive trait | No. of F2 offspring |
| Round seeds | Wrinkled seeds | 7524 |
From these results, it can be concluded that the actual number of round seeds he obtained was ______
If the ratio of each phenotype of the seeds of pea plants in the F2 generation is 9 : 3 : 3 : 1, it is known as :
(a) tetrahybrid ratio
(b) monohybrid ratio
(c) dihybrid ratio
(d) trihybrid ratio
One of the following traits cannot be inherited. This one is :
(a) colour of eyes
(b) colour of skin
(c) size of body
(d) nature of hair
If we pure-bred tall (dominant) pea plant with pure-bred dwarf (recessive) pea plant we will get pea plants of F1 generation. If we now self-cross the pea plant of F1 generation, then we obtain pea plants of F2 generation.
(a) What do the plants of F2 generation look like?
(b) State the ratio of tall plants to dwarf plants in F2 generation.
(c) State the type of plants not found in F1 generation but appeared in F2 generation, mentioning the reason for the same.
