Multiple Choice QuestionsWhen a tall plant with rounded seeds (TTRR) is crossed with a dwarf plant with wrinkled seeds (ttrr), the F1 generation consists of tall plants with rounded seeds. How many types of gametes an F1 plant would produce ?
One
Three
Four
Eight
A.
One
Parent generation - Tall round seeds Dwarf wrinkled seeds
TTRR x ttrr
Gametes - TR tr
F1 generation - TtRr
Therefore, only one type of gametes is produced in F1 plants, i.e. TtRr or Tall round seeds.
Tetradynamous stamens are found in :
Chrysanthemum
Zinnia
Poppy
Brassica
D.
Brassica
Tetradynamous condition of stamens is found in mustard (Brassica campestris) plant of Family- Cruciferae (Brassicaceae). In tetradynamous condition, there are six stamens, four stamens remain long and two short.
Mutations which alter nucleotide sequence within a gene are :
frame shift mutations
base pair substitutions
both 'a' and 'b'
none of these
A.
frame shift mutations
Gene mutation or point mutation is the result of a change in the nucleotide sequence of the DNA molecule in a particular region of the chromosome. It occurs in the form of duplication, insertion, deletion, inversion or substitution of bases. Frame- shift mutation is the addition or deletion of a base that may change the reading frame of nucleotide sequence.
Base pair substitution is a type of mutation involving replacement or substitution of a single nucleotide base with another in DNA or RNA molecule.
Phytochrome occurs in two forms. In which form it promotes the germination of seeds of some species ?
Pfr forms
Pr forms
Both forms
None of these
A.
Pfr forms
Pfr form of phytochrome refers to physiologically active form whereas Pr form refers to inactive form.
Red light formation means the formation of Pfr. It helps in the induction of seed germination. On the contrary, far red light or Pr formation inhibits the germination.
Human immuno deficiency virus causes
Acquired immuno deficiency syndrome
Anthrax
Tuberculosis
Polio
A.
Acquired immuno deficiency syndrome
AIDS or Acquired Immuno Deficiency Virus is caused by HIV. It is a chronic, life threatning condition caused by HIV.
Insect resistance transgenic cotton has been produced by inserting a piece of DNA from:
an insect
a bacterium
a wild relative of cotton
a virus
B.
a bacterium
Insect (i.e., Bollwarm) resistant transgenic cotton has been produced through genetic engineering by inserting a piece of DNA from bacterium Bacillus thuringensis.
Which of the following pair is characterised by swollen lips, thick pigmented skin of hands and legs and irritability ?
Iodine - Goitre
Protein - Kwashiorkor
Thiamine - Beri-beri
Nicotinamide- Pellagra
D.
Nicotinamide- Pellagra
Pellagra is a disease caused by the deficiency of nicotinamide or nicotinic acid or niacin or vitamin B3. It is common among individuals eating food with low tryptophan. The symptoms of pellagra are inflammation of skin or Dermatitis, diarrhoea and dementia.
Diadelphous stamens are the characteristic features of :
Ranunculaceae
Fabaceae
Poaceae
Malvaceae
B.
Fabaceae
In diadelphous condition, stamens are arranged in two bundles. Diadelphous stamens are the characteristic features of Family- Fabaceae.
Which organism was used by Beadle and Tatum to proposed one gene-one enzyme hypothesis ?
E. coli
Nostoc
Drosophila
Neurospora
D.
Neurospora
G.W. Beadle and E.L. Tatum demonstrated by the biochemical mutation experiment in Neurospora that genes express themselves through synthesis of enzymes. They proposed a concept called "one gene-one enzyme hypothesis".
The molecular structure of insulin was first described by :
Korenberg
Swaminathan
Richardson
Sanger
D.
Sanger
Insulin is a protein of 51 amino acids. It is a peptide hormone, made up of two polypeptide chains joined together by disulphide bridges. It is produced by the beta cells of the pancreatic islets. Sanger was the first person to complete the amino acid sequence of insulin.
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