Plant Pathology - Study Mode

[#396] Female gametophyte of angiosperms is represented by
Correct Answer

(C) Embryo sac

Explanation

Solution: The female gametophyte of angiosperms is represented by the Embryo sac. The female gametophyte develops within the ovule and generally consists of three antipodal cells, one central cell, two synergid cells, and one egg cell. The female gametophyte is also commonly called the embryo sac or megagametophyte.

[#397] Black heart of potato is caused due to
Correct Answer

(B) O 2 deficiency

Explanation

Solution: The black heart of potato is caused due to O 2 deficiency. The black heart occurs primarily in storage when the tubers do not receive enough oxygen. Blackening of the tuber center follows acute oxygen deficiency associated with an either low temperature in confined storage or high field soil temperatures. The tissue dies from the inside out and turns jet black.

[#398] Triple super phosphate contains
Correct Answer

(A) 40 - 48% P 2 O 5

Explanation

Solution: Triple super phosphate contains 40 - 48% P 2 O 5 . Triple superphosphate is a component of fertilizer that primarily consists of monocalcium phosphate, Ca(H 2 PO 4 ) 2 . Triple superphosphate is obtained by treating phosphate rock with phosphoric acid. Triple superphosphates [TSPs, Ca(H 2 PO 4 ) 2 ·H 2 O] were produced by exothermic reactions of oyster shells and different concentrations of phosphoric acid in a molar ratio of 1 : 2.

[#399] Yellow mosaic of legumes was first reported in India from
Correct Answer

(C) Delhi

Explanation

Solution: Yellow mosaic of legumes was first reported in India from Delhi. Yellow mosaic disease (YMD) was first reported in western India in the late 1940s in Lima bean and later in mungbean in northern India. Yellow mosaic virus (Begomovirus) is a major exotic disease of mungbean causing leaf discoloration and yield losses. The virus is spread between plants by the Silverleaf white fly (Bemisia tabaci).

[#400] Direction of conduction of food through phloem is
Correct Answer

(C) From leaves to roots

Explanation

Solution: Direction of conduction of food through phloem is from leaves to roots. Phloem is the vascular tissue that transports food (photosynthates) from the leaves to basal parts of the plant, and vascular cambium is undifferentiated tissue responsible for secondary growth and repair of damaged phloem. The main role of the phloem tissue is to transport carbohydrates from sources to sinks through the sieve elements, phloem is also composed of parenchyma cells, which play a key role in the storage of water, non-structural carbohydrates and storage proteins.