Long Answer Type(a) Explain the menstrual phase in a human female. State the levels of ovarian and pituitary hormones during this phase.
(b) Why is follicular phase in the menstrual cycle also referred as a proliferative phase ? Explain.
(c) Explain the events that occur in a Graafian follicle at the time of ovulation and thereafter.
(d) Draw a graafian follicle and label antrum and secondary oocyte
(a) As a senior biology student you have been asked to demonstrate to the students of secondary level in your school, the procedure(s) that shall ensure cross-pollination in a hermaphrodite flower. List the different steps that you would suggest and provide reasons for each one of them.
(b) Draw a diagram of a section of a megasporangiumof an angiosperm and label funiculus, micropyle, embryo sac and nucellus.
(a) The procedure to ensure cross-pollination in hermaphrodite flower
(i) Emasculation :- If the female parent bears bisexual flower, removal of Anther from the flower before the anther dehisces can ensure cross-pollination.
(ii) Bagging :- Emasculated flowers have to be covered with a bag of suitable size generally made up butter paper to prevent contamination of its stigma with unwanted pollen, this procedure is called Bagging.
When stigma of bagged flower attains receptivity, mature pollen grains collected from anthers of male parent and dusted to stigma and flowers are rebagged and fruits are allowed to develop.
(b)
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