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प्रश्न
According to the evolutionary theory, formation of a new species is generally due to
विकल्प
sudden creation by nature
accumulation of variations over several generations
clones formed during asexual reproduction
movement of individuals from one habitat to another
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उत्तर
accumulation of variations over several generations
Explanation -
According to the evolutionary theory, the accumulation of variations (resulting from errors in DNA copying and sexual reproduction) over several generations along with the operation of natural selection leads to the formation of new species.
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संबंधित प्रश्न
Explain Mendel’s dihybrid ratio with the help of any one cross.
State Mendel’s law of Independent Assortment.
A homozygous Tall plant (T) bearing red coloured (R) flowers is crossed with a homozygous dwarf plant (t) bearing white flowers (r):
(1) Give the Genotype and Phenotype of the F2 generation.
(2) Give the possible combinations of the gametes that can be obtained from the F2 hybrid.
(3) Give the dihybrid ratio and the phenotype of the offsprings of the F2 generation when two plants of the F1 generation above are crossed.
Complete the following sentence with appropriate word:
_______ is the ratio of dihybrid cross.
Complete the following sentence with appropriate word:
A character that is suppressed is _________.
Test cross involves
Select the period for Mendel’s hybridization experiments
Identify the statementls that is/are NOT the correct reason/s for Mendel's success in his hybridization experiments.
i. Each factor controlled the single trait and is located on separate chromosomes.
ii. In the pea plant, contrasting characters can be easily recognized.
iii. Mendel carefully recorded the number of plants of each type and expressed his results as ratios.
iv. Mendel performed biochemical assays for identifying the position of 'factors' on chromosome.
A cross between two tall plants resulted in offspring having few dwarf plants. What would be the genotypes of both the parents?
In a testcross involving F1 dihybrid flies, more parental-type offspring were produced than the recombinant-type offspring. This indicates ______.
A normal green male maize is crossed with albino female. The progeny is albino because ______.
A fruit fly exhibiting both male and female traits is ______.
Mendel’s Law of independent assortment holds good for genes situated on the ______.
What is the difference between genetic drift and change due to natural selection?
Do genetic combination of mothers play a significant role in determining the sex of a new born?
Two pea plants - one with round yellow seeds (RRYY) and another with wrinkled green (rryy) seeds produce F1 progeny that have round, yellow (RrYy) seeds.
When F1 plants are self-pollinated, which new combination of characters is expected in F2 progeny? How many seeds with these new combinations of characters will be produced when a total 160 seeds are produced in F2 generation? Explain with reason.
Sahil performed an experiment to study the inheritance pattern of genes. He crossed tall pea plants (TT) with short pea plants (tt) and obtained all tall plants in F1 generation.
When F1 plants were self-pollinated, a total of 800 plants were produced. How many of these would be tall, medium height or short plants? Give the genotype of F2 generation.
Independent assortment means:
In the Mendelian dihybrid cross when heterozygous round yellow is self grossed, round green offsprings are represented by the genotype.
The Law of independent assortment is applicable for the traits which ______
