The genetic mechanism, that prevents self pollen (from the same flower or other flowers of the same plant) from fertilising the ovules by inhibiting pollen germination or pollen tube growth in the pistil, is called as
1. Dioecy
2. Dichogamy
3. Monocliny
4. Self incompatibility
Plants pollinated by wind do not show
(1) Light and non-sticky pollen grains
(2) Well-exposed stamens
(3) Large-sized flowers
(4) Presence of single ovule in each ovary
Genetically and functionally self-pollination is cent percent ensured with seed formation even in the absence of pollinators by
Polygonum type embryo sac is
(1) Monosporic
(2) Seven celled with one largest binucleate cell
(3) Eight nucleated with 3 + 2 + 3 arrangement
(4) All are correct
Ovule generally differentiate a single _____ in the ______ region of the nucellus.
(1) Megaspore mother cell, micropylar
(2) Megaspore, micropylar
(3) Megaspore, mother cell, chalazal
(4) Primary
How many statement(s) is/are correct for pollen grains?
a. Parthenium is a cause of bronhial afflictions
b. Intine exhibits fascinating array of patterns and designs
c. Cytoplasm of pollen grain is surrounded by spermoderm
d. Generative cell is present when pollens are shed in 40 percent plants.
1. One 2. Two
3. Three 4. Four
Fossilization of pollen grains is helped by
(1) Compatible protein
(2) Sporopollenin
(3) Cellulose
(4) Pectin
The largest cell of embryo sac is
(1) Antipodal
(2) Synergid
(3) Central cell
(4) Egg
Read the statements carefully and select correct option.
A. Pollen grains of carrot grass cause bronchial afflictions
B. Pollen viability is maximum in wheat
C. Pollen grains are well preserved as, fossils due to pecto-cellulose
D. Pollen grain aperture is devoid of sporopollenin.
1. A and D 2. A and B
3. B and C 4. A, B and D
Which of the following statements for generative cell is incorrect?
(1) Floats in the cytoplasm of vegetative cell
(2) Has abundant food reserve
(3) Spindle-shaped
(4) Dense cytoplasm with a nucleus