Which among the following statement is incorrect with respect to tapetum?
(1) It nourishes developing pollen grains.
(2) It has dense cytoplasm.
(3) It is the innermost wall layer of microsporangia.
(4) Cells have single nucleus only.
Microsporangium is generally surrounded by 4 wall layers. Which of the following 3 wall layers perform the function of protection and help in the dehiscence of anther to release the pollen?
(1) Epidermis, tapetum, endothecium
(2) Epidermis, aril, endothecium
(3) Epidermis, endodermis, mesocarp
(4) Epidermis, middle layer and endothecium
The following is the diagram of T.S. of anther. Identify the parts labelled A, B and C.
1. | A - Connective tissue, B - Pollen grains, C - Endothecium |
2. | A - Endothecium, B -Connective tissue, C - Pollen grains |
3. | A - Pollen grains, B - Connective tissue, C - Endothecium |
4. | A - Endothecium, B - Pollen grains, C - Connective tissue |
Examine the figure given below and select the right option giving all the four parts a,b,c and d. Correctly identify
a | b | c | d | |
1. | Endo- thecium |
Tapetum | Micro- spore mother cell |
Middle layer |
2. | Tapetum | Endo- thecium |
Micro- spore mother cell |
Middle layer |
3. | Endo- thecium |
Middle layer |
Tapetum | Micro- spore mother cell |
4. | Endo- thecium |
Micro- spore mother cell |
Middle layer |
Tapetum |
Mark the incorrect statement
1. | Outer three layers of anther wall are protective in function |
2. | Sporogenous tissue occupies the centre of each microsporangium |
3. | Cells of tapetum and endothecium show increase in DNA contents by endomitosis and polyteny |
4. | Ploidy level of microspore tetrad is haploid |
Match the following:
1 | Sporogenous tissue | I | Process of formation of microspores from PMC by meiosis |
2 | Microspore tetrad | II | Microspores arranged in cluster of four cells |
3 | Microsporogenesis | III | Formation of microspore tetrad by meiosis |
4 | Tapetum | IV | Nourishes pollen grains |
(1) 1-III ; 2-I ; 3-II ; 4-IV
(2) 1-III ; 2-II ; 3-I ; 4-IV
(3) 1-II ; 2-III ; 3-I ; 4-IV
(4) 1-II ; 2-III ; 3-IV ; 4-I
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 among the following is incorrect with respect to microsporogenesis?
(1) The cells of the sporogenous tissue undergo mitotic divisions to form microspore tetrads.
(2) Each cell of the sporogenous tissue is capable of giving rise to a microspore tetrad. Each one is a potential pollen or microspore mother cell (PMC).
(3) The microspores are arranged in a cluster of four cells called as the microspore tetrad.
(4) Inside each microsporangium several thousands of microspores or pollen grains are formed that are released with the dehiscence of anther.
All of the following statements are correct except:
1. | The proximal end of the filament is attached to the thalamus or the petal of the flower. |
2. | The anther is a four-sided structure consisting of four microsporangia, two in each lobe.
|
3. | The number and length of stamens are variable in flowers of different species.
|
4. | In a longitudinal section, a typical microsporangium appears near circular in outline. |
The layers in the walls of the microsporangium that helps in the dehiscence of anther to release the pollen include:
I: | Epidermis |
II: | Endothecium |
III: | Middle layers |
IV: | Tapetum |
1. | I and II only | 2. | I, II, and III only |
3. | II and III only | 4. | I, II, III, and IV |