Advertisements
Advertisements
प्रश्न
How do Mendel’s experiments show that the traits may be dominant or recessive?
Advertisements
उत्तर
Mendel crossed purebred tall pea plants with purebred dwarf pea plants and found that only tall pea plants were produced in the first generation, and there were no dwarf pea plants. He concluded that the first generation showed the traits of only one of the parent plants tallness. The trait of the other parent plant dwarfness did not show up in the progeny of the first generation.
He then crossed the tall pea plants obtained in the first generation (F1 generation) and found that both tall plants and dwarf plants were obtained in the second generation (F2 generation) in the ratio of 3 : 1. Mendel noted that the dwarf trait of the parent pea plant which disappeared in the first generation progeny reappeared in the second generation. In this way, Mendel’s experiments with tall and dwarf pea plants showed that the traits may be dominant and recessive.
APPEARS IN
संबंधित प्रश्न
Outline a project which aims to find the dominant coat colour in dogs.
What type of plants were used by Mendel for conducting his experiments on inheritance?
It it an example of monohybrid cross or dihybrid cross?
What is the genotype of tall plants which always produced tall offspring
Give the contrasting traits of the following characters in pea plant and mention which is dominant and which is recessive:
Yellow seed
Give the contrasting traits of the following characters in pea plant and mention which is dominant and which is recessive :
Round seed
How do Mendel's experiments show that traits may be dominant or recessive?
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
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?
Mendel first crossed pure-bred pea plants having round-yellow seeds with pure-bred pea plants having wrinkled-green seeds and found that only round-yellow seeds were produced in the F1 generation. When F1generation pea plants having round-yellow seeds were cross-bred by self pollination, then peas having round-yellow seeds, round green seeds, wrinkled-yellow seeds and wrinkled-green seeds were produced. Mendel collected a total of 2160 seeds.
(a) What will be the number of (i) round green seeds (ii) wrinkled green seeds (iii) round yellow seeds, and (iv) wrinkled-yellow seeds?
(b) Which 'ratio' as established by Mendel have you made use of in answering the part (a) above?
One of the following traits cannot be inherited. This one is:
One of the following traits of the parents cannot be passed on to their future generations. This trait is:
Answer the following question.
Name the plant Mendel used for his experiment. What type of progeny was obtained by Mendel in F1 and F2 generations when he crossed the tall and short plants? Write the ratio he obtained in F2 generation plants.
Why are the traits acquired during the life time of an individual not inherited? Explain.
____________ refers to the transmission of genetic information from parental generation to next generation.
In humans, if gene B gives brown eyes and gene b gives blue eyes, what will be the colour of eyes of the persons having combinations
(i) Bb and (ii) BB?
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 pea plant with white flowers (vv) and pea plant with violet flowers (VV) resulted in F2 progeny in which ratio of violet (VV) and white (vv) flowers will be ______.
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.
