- Plan an experiment and prepare a flow chart of the steps that you would follow to ensure that the seeds are formed only from the desired sets of pollen grains. Name the type of experiment that you carried out.
- Write the importance of such experiments.
OR
Describe the role of pituitary and ovarian hormones during the menstrual cycle in a human female
- Plan an experiment and prepare a flow chart of the steps that you would follow to ensure that the seeds are formed only from the desired sets of pollen grains. Name the type of experiment that you carried out.
- Write the importance of such experiments.
OR
Describe the role of pituitary and ovarian hormones during the menstrual cycle in a human female
Artificial hybridisation is a technique which ensures that the seeds are formed only from the desired set of pollen grains. It includes emasculation and bagging. Removal of stamens or anthers or killing of pollen grains of a bisexual flower without affecting the female reproductive organs is called emasculation. The emasculated flower is immediately enclosed in a plastic or butter paper bag to avoid pollination by unwanted pollen. This process is called bagging.
Experiment and flow chart of artificial hybridisation:
Remove the anthers of a bisexual flower using a pair of forceps.
↓
Immediately cover the emasculated flower with a plastic or butter paper bag.
↓
Collect the mature and viable pollen grains from the anthers of the male parent.
↓
Dust the pollen grains on the stigma of the female plant.
↓
Replace the bag immediately and allow the fruits to develop.
Importance of artificial hybridisation:
- It helps plant breeders to cross a particular plant with desired pollen grains.
- This technique helps in the production of hybrids without contamination by unwanted pollen grains.
OR
Follicle-stimulating hormone (FSH) and luteinising hormone are pituitary hormones. Oestrogen and progesterone are ovarian hormones.
Functions of pituitary and ovarian hormones:
HormoneFunctions i. Stimulates the ovarian follicles to secrete oestrogen.FSHii. Stimulates the proliferation of the endometrium of the uterine wall. iii. Stimulates the maturation of Graafian follicles. i. Stimulates the release of ovum.LHii. Develops corpus luteum and secretion of progesterone. iii. Maintains pregnancy.Oestrogeni. Controls the changes in the secondary sex organs in the first half of the menstrual cycle. ii. Stimulates growth, maturation and functions of secondary sex organs. iii.Repairs the damaged tissues of the uterus and fallopian tubes after menstruation. iv. Stimulates the maturation of ova development of uterine lining and mammary glands.Progesteronei. Facilitates the preparation of the endometrium for implantation. ii.Inhibits the contraction of the uterus and the development of new follicles.
Artificial hybridisation is a technique which ensures that the seeds are formed only from the desired set of pollen grains. It includes emasculation and bagging. Removal of stamens or anthers or killing of pollen grains of a bisexual flower without affecting the female reproductive organs is called emasculation. The emasculated flower is immediately enclosed in a plastic or butter paper bag to avoid pollination by unwanted pollen. This process is called bagging.
Experiment and flow chart of artificial hybridisation:
Remove the anthers of a bisexual flower using a pair of forceps.
↓
Immediately cover the emasculated flower with a plastic or butter paper bag.
↓
Collect the mature and viable pollen grains from the anthers of the male parent.
↓
Dust the pollen grains on the stigma of the female plant.
↓
Replace the bag immediately and allow the fruits to develop.
Importance of artificial hybridisation:
- It helps plant breeders to cross a particular plant with desired pollen grains.
- This technique helps in the production of hybrids without contamination by unwanted pollen grains.
OR
Follicle-stimulating hormone (FSH) and luteinising hormone are pituitary hormones. Oestrogen and progesterone are ovarian hormones.
Functions of pituitary and ovarian hormones:
HormoneFunctions i. Stimulates the ovarian follicles to secrete oestrogen.FSHii. Stimulates the proliferation of the endometrium of the uterine wall. iii. Stimulates the maturation of Graafian follicles. i. Stimulates the release of ovum.LHii. Develops corpus luteum and secretion of progesterone. iii. Maintains pregnancy.Oestrogeni. Controls the changes in the secondary sex organs in the first half of the menstrual cycle. ii. Stimulates growth, maturation and functions of secondary sex organs. iii.Repairs the damaged tissues of the uterus and fallopian tubes after menstruation. iv. Stimulates the maturation of ova development of uterine lining and mammary glands.Progesteronei. Facilitates the preparation of the endometrium for implantation. ii.Inhibits the contraction of the uterus and the development of new follicles.
