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 |
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
A typical angiosperm anther is bilobed with each lobe having two theca i.e. dithecous. Theca is separated often by :
1. A longitudinal groove running lengthwise.
2. A longitudinal groove running breadth wise.
3. A transverse groove running breadth wise.
4. A transverse groove running lengthwise.
Four statements are given below. How many of them are correct?
(1) The anther is a tetragonal structure, with four microsporangia at corners, two in each lobe.
(2) Microsporangia develops further and becomes a pollen sacs.
(3) A typical microsporangia is surrounded by four layered wall, 3-protective and 1 nutritional.
(4) The nutritive layer is densely cytoplasmic with more than one nucleus
Options :
1. 3
2. 4
3. 2
4. 1
Which of the following statement is not correct for pollen grain?
1. It represents male gametophyte.
2. It is a spherical structure, about 25-50 micrometers in diameter.
3. Pollen grains are rich in nutrients.
4. In family rosaceae, leguminoseae and solanaceae pollen lose viability in 30 minute.
In which organ the growth of pollen tube is observed, till it reaches the ovules?
A.Pollen tube
B.Style
C.Ovary
D.Stigma
Read the statements and select option representing correct statements with respect to stamen.
A. The distal end of filament is attached to thalamus.
B. A typical anther is dithecous and bisporangiate.
C. Connective is sterile vasculated tissue.
D. Microsporangia develop further and become pollen sacs.
1. A & B
2. A & C
3. B & C
4. C & D
Genetically and functionally self-pollination is cent percent ensured with seed formation even in the absence of pollinators by
(1) Bisexuality
(2) Dicliny
(3) Geitonogamy
(4) Cleistogamy