Related Questions

Consider the following statements regarding the germination of pollen grain and choose the correct answer:
1. The content of the pollen is a true male gametophyte
2. The pollen tube comes out due to the protrusion of the exine through the germ pore
3. When the pollen grain has germinated, the pollen tube penetrates the stigma through the stigmatic papillae
4. Some stigmas have a continuous cuticle in which pollen tubes penetrate by enzyme action
Consider the following statements and choose the correct answer:
1. In angiosperms the pollination consists of transference of the pollen grains from the anther to the stigma either by self-pollination or by cross-pollination
2. Pollen grain is shed from the pollen sac in the two-celled stage
3. The exine of each microspore grows out into a tube, called the pollen tube
4. The growth of pollen tube is stimulated by sugary substances secreted by the stigma
Which of the following statements relating to 'role' is/are true and false?
1 The system of various roles that the individual carries and performs is 'role set'.
2. The system of various roles of which an individuals role is a part in 'role space'.
3. Self role integration, proactivity, creativity and conformation are ingredients of the role making dimension of role efficacy.
4. Role stress is caused by both role space conflict and role set conflict.
In which of the following plants, the pollen grains do not separate apart but remain adhered in tetrad to form "Compound pollen grains"?
Consider the following statements regarding Xenia and choose the correct answer:
1. If a white variety (yy) is pollinated with pollen from a yellow variety (YY), one of the male gametes (Y) will unite with the egg (y) to produce a hybrid embryo (Yy) which will act as a heterozygote for yellow endosperm in the next generation
2. The second male gamete (Y) will unite with the two polar nuclei (y, y) and produces the primary endosperm nucleus (Yyy) which is triploid
3. If a yellow endosperm variety (YY) is crossed with pollen from a white grained variety, the grains produced are white like the pollen parent
Assertion (A) Each role must have enough stressers which may help the role occupant to stretch himself/herself to meet the challenge. In the role, where the scope is limited to routine work, the role occupants do not perceive any challenge.
Reason (R) While every role has some routine elements, challenge can also be incorporated into every role. However, the challenge should not exceed an optimal limit, otherwise it may produce dysfunctional stress, resulting in poor performance or damage to the health of the employee in the long-run.
How do the pollen grains break open from the pollen sacs?
How many pollen mother cells will form 1000 pollen grains
Consider the following statements and choose the correct answer:
1. Intense or strong light retards the growth of shoot
2. Shade plants are shorter and stockier than sun plants
3. Shade plants have dense covering of hairs while sun plants are less hairy
4. The stems of shade plants are taIler and more branched than that of sun plants
Statement 1: Removing of moisture content for grains in the food industry follows the thin layer model of drying bed. Statement 2: The model for removing moisture from grains is computerized to find out the exact amount of time of exposure of grains for the removal of moisture.