Advertisements
Advertisements
प्रश्न
The most obvious outcome of the reproduction process is the generation of individuals of similar design, but in sexual reproduction they may not be exactly alike. The resemblances as well as differences are marked. The rules of heredity determine the process by which traits and characteristics are reliably inherited. Many experiments have been done to study the rules of inheritance. |
- Why an offspring of human being is not a true copy of his parents in sexual reproduction?
- While performing experiments on inheritance in plants, what is the difference between F1 and F2 generation?
- (A) Why do we say that variations are useful for the survival of a species over time?
OR
(B) Study Mendel's cross between two plants with a pair of contrasting characters.
RRYY × rryy Round Yellow Wrinkled Green He observed 4 types of combinations in F2 generation. Which of these were new combinations? Why do new features which are not present in the parents, appear in F2 generation?
उत्तर
- In sexual reproduction, a human's offspring is not a true replica of his parents because the genetic material from the mother's and father's gametes is mixed together in humans. So, in addition to some new recombination, the offspring has traits from both parents.
- The selected people are crossed to create the F1 generation, which is the first generation. The F2 generation is the second one created through the mating of any two members of the F1 generation.
- (A) Over time, variations can help a species survive because they give natural selection the starting point from which to work. Any population will always have some variation, and this variation may be advantageous, neutral, or harmful to an individual's chance of surviving.
OR
(B) Yellow and wrinkled seeds and round and green seeds were two novel combinations. These emerge in the F2 generation as a result of novel combinations of recessive traits whose alleles were present in the F1 generation but unable to express themselves. In F2, they appeared by combining in a different way.
APPEARS IN
संबंधित प्रश्न
Describe the different methods of asexual reproduction. Give examples.
State the main difference between asexual and sexual reproduction.
Factors responsible for the rapid spread of bread mold on slices of bread are ______
(i) a large number of spores
(ii) availability of moisture and nutrients in bread
(iii) presence of tubular branched hyphae
(iv) formation of round shaped sporangia
Which of the following is the correct sequence of events of sexual reproduction in a flower?
Characters transmitted from parents to offspring are present in
The ability of a cell to divide into several cells during reproduction in Plasmodium is called
Write two points of difference between asexual and sexual types of reproduction. Describe why variations are observed in the offspring formed by sexual reproduction.
One morning as Paheli strolled in her garden she noticed many small plants which were not there a week ago. She wondered where they had come from as nobody had planted them there. Explain the reason for the growth of these plants.
Differentiate between binary fission in Amoeba and binary fission in Leishmania.
Assertion (A): Most of the plants close their stomata at night.
Reason (R): Closing of stomata helps to conserve water as large amount of water evaporates from the leaves.