Benefits of mycorrhizae are:
(i) Resistance to root-borne pathogens.
(ii) Tolerance of salinity and absorption of phosphorus.
(iii) Tolerance to drought.
(iv) Overall increase in the plant growth and development.

Q. 48. Consider the following statement about Mycorrhizal fungi.
1. They form a network of fine filaments associate with plant roots to draw nutrients and water from the soil.
2. Ectomycorrhizal fungi develop exclusively on the exterior of root cells.
3. Mycorrhizal fungi increase plant tolerance to different environmental stresses.
4. It decreases plant tolerance to soil salinity.
Which of the above statement(s) is/are correct?

Q. Which among these are the objectives of biotechnology in the field of agriculture?
(A) To produce pest-resistant varieties of plants
(B) To decrease the nitrogen absorption
(C) To increase tolerance to water stress of the plant
(D) To improve the non-agronomic characters

Choose the correct option:

Q. Read the given statements and identify the plant hormones X, Y and Z.
(i) Hormone Y suppresses flowering in mango and also promotes rapid internode/petiole elongation in deep water rice plants and hence helping leaves or upper part of shoot to remain above water.
(ii) Hormone X promotes root growth and root hair formation.
(ii) Hormone Z inhibits the seed germination, increases the tolerance of plant to various stresses, play important role in seed development maturation and dormancy.

Q. The growth regulator associated with drought stress tolerance is ........

Q. Match and find the correct match.

$I$	$II$
$\left(a\right)$ 2, 4-D	$\left(i\right)$ Promotion of lateral shoot growth
$\left(b\right)$ ${GA}_3$	$\left(ii\right)$ Thinning in cotton
$\left(c\right)$ Ethephon	$\left(iii\right)$ Stress tolerance
$\left(d\right)$ ABA	$\left(iv\right)$ Brewing industry
	$\left(v\right)$ Weed free lawns