question_answer

Define binary fission. What is the difference between binary fission in Plasmodium and Euglena?

OR

(i) Where is female reproductive system situated in the body?

(ii) What is ovarian cycle?

Answer:

Binary fission is the division of the parent into two offspring which are morphologically & genetically similar to the parent and to each other. During this process, nuclear division is followed by cytoplasmic division. There are three modes of binary fission - simple binary fission, transverse binary fission and longitudinal binary fission.

Plasmodium reproduces by transverse binary fission. In this method, the plane of cytoplasmic division coincides with the transverse axis of the individual whereas Euglena reproduces by longitudinal binary fission. In this mode, the plane of cytoplasmic division coincides with the longitudinal axis of the individual.

OR

(i) The female gonads, ovaries, are located within the lower abdominal cavity. The ovary contains many follicles composed of a developing egg surrounded by an outer layer of follicle cells.

(ii) After puberty, the ovary cycles between a follicular phase (maturing follicles) and luteal phase (presence of the corpus luteum) and menstruation phase. These cyclic phases are interrupted only by pregnancy and continue until menopause, when reproductive capability ends.