Advertisements
Advertisements
Questions
What are the components of the DNA molecule?
Which are the components of the DNA molecule?
Advertisements
Solution
A DNA molecule is made up of two helical strands consisting of deoxyribose sugar, a phosphate group (derived from phosphoric acid), and pairs of nitrogenous bases. These three together are called a nucleotide.
RELATED QUESTIONS
"A trait may be inherited, but may not be expressed." Justify this statement with the help of a suitable example.
In one of his experiments with pea plants, Mendel observed that when a pure tall pea plant is crossed with a pure dwarf pea plant in the first generation, F1, only tall plants appear.
(a) What happens to the traits of the dwarf plants in this case?
(b) When the F1-generation plants were self-fertilised, he observed that in the plants of the second generation, F2, both tall plants and dwarf plants were present. Why it happened? Explain briefly.
Define heredity.
List any two contrasting characters other than roundness of pea plants that Mendel used in his experiments with pea plants.
A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits – blood group A or O – is dominant? Why or why not?
How is the equal genetic contribution of male and female parents ensured in the progeny?
To perform an experiment to identify the different parts of an embryo of a dicot seed, first of all you require a dicot seed. Select dicot seeds from the following group:
Wheat, Gram, Maize, Pea, Barley, Ground-nut
(A) Wheat, Gram and Pea
(B) Gram, Pea and Ground-nut
(C) Maize, Pea and Barley
(D) Gram, Maize and Ground-nut
What constitutes the link between one generation and the next?
Mendel said that the characteristics or traits of organisms are carried from one generation to the next by internal factors which occur in pairs. What is the modern name for these factors?
State whether the following statement is true or false :
The sex of an infant is not a case of inheritance of characteristics.
What are the units of heredity.
For his experiments on heredity, Mendel used :
papaya plants
potato plants
pea plants
pear plants
The visible characteristic in an organism is known as ______.
Which of the following statement is incorrect?
(a) for every hormone there is a gene
(b) for every protein there is a gene
(c) for production of every enzyme there is a gene
(d) for every type of fat there is a gene
Pure-bred tall pea plants are first crossed with pure-bred dwarf pea plants. The pea plants obtained in F1generation are then cross-bred to produce F2 generation of pea plants.
(a) What do the plants of F1 generation look like?
(b) What is the ratio of tall plants to dwarf plants in F2 generation?
(c) Which type of plants were missing in F1 generation but reappeared in F2 generation?
A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits-blood group A or O - is dominant? Why or why not?
"It is possible that a trait is inherited but may not be expressed." Give a suitable example to justify this statement.
Define Heredity. Give two examples.
In the following figure showing a germinating gram seed, name the parts labelled as A, B and C:
Why is Part 'B' considered to be important during germination?
