Hybrid seeds have to be produced every year because:
(1) Hybrid plants become sterile in coming years

(2) They show more heterosis in coming years

(3) Hybrid vigour is not maintained beyond one generation as segregation of genes begins in the second generation

(4) Hybrid seed industry tends to increase cost of the seeds

Active research is going on in many laboratories around the world to understand the genetics of apomixis. What is the purpose of such active research?
(1) Hybrid plants are directly formed by apomixis

(2) Apomixis is the method to produce seed without fertilization

(3) To transfer apomictic genes into hybrid varieties which will prevent loss of hybrid vigour with successive years

(4) Apomixis produces genetically different individuals

Both, autogamy and geitonogamy are prevented in:

(1) Papaya           

(2) Cucumber       

(3) Castor             

(4) Maize

Pollen tube, after reaching the ovary, does not show following event:
(1) Enters the ovule through the micropyle

(2) May enter the ovule through chalaza

(3) Enters one of the synergid through filiform apparatus

(4) Chemotactic movement of pollen tube towards synergid

In which organ the growth of pollen tube is observed, till it reaches the ovules?

A.Pollen tube

B.Style

C.Ovary

D.Stigma

Polygonum type embryo sac is

Which of the following statements is false?
(1) Some 2000 years old viable seeds of Pheonix dactylifera were discovered during archaeological excavation of King Herod's palace near Dead Sea

(2) Record of 10,000 years of dormancy of seeds has been estimated in Lupinus arcticus

(3) The number of seeds in each fruit in case of orchid and some parasitic forms like Orobanche and Striga is one

(4) Many fruits have evolved mechanisms for dispersal of seeds

Which of the following will lose its economic value if fruits are produced through parthenocarpy:

(1) Citrus             

(2) Banana           

(3) Grape             

(4) Pomegranate

Which of the following is not correct?
(1) As the seed matures, its water content is reduced and seeds become relatively dry(10-15% moisture by mass)

(2) The seed dormancy is the internal or innate inhibition of generation of normal or viable seeds

(3) Embryo in dormant seed shows higher rate of general metabolic rate

(4) Because of dormancy seeds remain viable for longer period and can be stored

Which are the external conditions required for seed germination:
(1) Oxygen, carbon dioxide and suitable temperature

(2) Oxygen, light and suitable temperature

(3) Light, moisture and suitable temperature

(4) Oxygen, moisture and suitable temperature