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Which of the following statement is not correct regarding variation in species?
Only those variation which are useful and have advantage get selected.
Some dinosaurs had feathers although they could not fly but birds have feathers that help them to fly. In the context of evolution this means that
Which of the following statement is incorrect ?
The information coded in DNA (genes) is for only polypeptides (proteins). Insulin hormone is peptide and all enzyme are also proteins.
Genetic material is exchanged during
During formation of gametes meiosis occurs resulting in exchange of genes by the process of crossing over.
The fossil remains of Archaeopteryx is a connecting link between
One tall pea plant and one dwarf pea plant on crossing resulted in 50% tall and 50% dwarf pea plant. The plants which were crossed were
50% Tt Tall and 50% tt dwarf
Wild cabbage has evolved into new varieties fike cabbage, broccoli and cauliflower by
A cross between a tall plant (TT) and short pea plant (tt) resulted in progeny that were all tall plants because
All the progeny of this cross will have genotype Tt and a recessive gene cannot express itself in presence of dominant gene. A pea plant will be dwarf only when both the alleles are tt.
If yellow seeded wrinkled pea plant (YYrr) is crossed with green seeded round pea plant (yyRR), the seeds produced in F1 generation are
If a round, green seeded pea plant is crossed with wrinkled, yellow seeded pea plant, the seeds produced in F1 generation are round and yellow.
Natural selection is called ‘survival of the fittest'.Which of the following statements best describes an organism?
A zygote which has an X chromosome inherited from the father will develop into a
Which concept was not included in Charles Darwin’s theory of Natural Selection?
In human males all the chromosomes are paired perfectly except
(i) 21st chromosome
(ii) Y chromosome
(iii) small chromosome
(iv) X chromosome
Human males have 23 pairs of autosomes and XY sex chromosomes.
What is the difference between genetic drift and change due to natural selection?
Both natural selection and genetic drift are mechanisms for evolution. The key distinction is that in genetic drift allele frequencies change by chance, whereas in natural selection allele frequencies change by differential reproductive success and genetic drift does not involve competition between members of species.
Sex of a child is determined by
Male produces two types of sperms 50% sperms have X chromosome and rest 50% have Y chromosome. If sperm having X chromosome fertilises ovum the sex of child will be female and in case sperm having Y chromosome fertilises the egg the child will be male.
To study the natural phenomenon of inheritance, Mendel selected the pea plants. Which of the following properties were suitable for their studies?
(i) Plants would easily self pollinate or cross pollinate in nature.
(ii) Plants were easily grown in garden soil with a considerably shorter generation time.
(iii) Pea plants do not require the true-breeding for hybridisation experiments.
(iv) Many parts of the plant such as pod, seed, flower, cotyledons showed distinct phenotypes.
Plant is easily grown in garden soil so it can be easily used for experiment.
Mendels experiment is to prove that pure tall and pure dwarf give different types of progency. So, he have to take a plant which have distinct phenotype. Therefore he used pea.