The phenomenon that operates in the formation of root or shoot in a callus culture is
differentiation
re-differentiation
de-differentiation
re-juvenation
A.
differentiation
The cells derived from root apical and shoot apical meristems and cambium differentiate and mature to perform special functions. This act leading to maturation is termed as differentiation.
Differentiation is the process by which a less specialized cell becomes a more specialized cell type. It is part of developmental biology. Different tissues have different kinds of organisms inside the cells. Differentiation occurs many times during the development of a multicellular organism.
Which of the following genes do not occur naturally in living organisms
Bt genes
RNAi genes
Cry genes
Endogeneous cytoplasmic defence genes
One hormone hastens maturity period in juvenile conifers, a second hormone controls xylem differentiation, while the third hormone increases the tolerance of plants to various stresses. They are respectively
Gibberellin, Auxin, Ethylene
Auxin, Gibberellin, Cytokinin
Gibberellin, Auxin, ABA
Auxin, Gibberellin, ABA
Vernalisation is subjected to plants growing in
tropical areas
sub tropical areas
temperate areas
hot areas/arctic region.
Assertion: No secondary growth takes place in monocots.
Reason: Secondary growth is not related with cambium.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Gibberellins can promote seed germination because of their influence on
rate of cell division
production of hydrolysing enzymes
synthesis of abscisic acid
absorption of water through hard seed coat.
Assertion: Plant growth regulators (PGRs) are very important for plant growth and development.
Reason: Auxins do not induce flowering in gymnosperms
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion: Yeasts are unicellular fungi that are used in bakery and brewery industries.
Reason: Potato spindle tuber disease is caused by viroids
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion: A correct concentration of auxin and cytokinin is required for the development of root and shoot in a callus.
Reason: When the ratio of kinetin to auxin is high, then only shoots develop. But when the ratio is low then only roots develop.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
