Biology Test 32

Epididymis is a 6m long coiled tube between vasa efferentia and vas deferens. It is found in poster lateral side of both the testes. Epididymis consist of 3 parts- caput epididymis, corpus epididymis & cauda epididymis.

Peritoneal covering of ovary is mesovarium. Ovary, in the abdominal cavity, is suspended from the abdominal wall by this peritoneal covering, mesovarium.

Progesterone is secreted in high conc. during the luteal phase and during pregnancy as well. Progesterone is secreted for about 14 days until corpus luteum turns into corpus albicans. Hormone oxytocin, secreted from the pituitary and prostaglandins from the placenta, cause powerful contraction of smooth muscles of uterus which help in hastening child birth.

The additional embryos arising from the maternal sporophytic tissue, ie, outside the embryo sac (from nucellus or integuments) are called adventive embryo and the polyembryony as nucellar polyembryony, e.g. Citrus, Mangifera, Opuntia, Trillium, etc.The additional embryos arising from the maternal sporophytic tissue, ie, outside the embryo sac (from nucellus or integuments) are called adventive embryo and the polyembryony as nucellar polyembryony, e.g. Citrus, Mangifera, Opuntia, Trillium, etc.

Syphilis is a sexually transmitted disease caused by the bacterium Treponema pallidum. The various stages of this disease with symptoms are: 
Stage 1: Infectious painless ulcers on the genitals 
Stage 2: Appearance of dark skin lesions, headaches, joint pains, fever, hair loss, swelling of lymph nodes, etc. 
Stage 3: Aortic impairment leading to heart trouble, and blindness.

Test tube baby means ovum fertilized outside the mother body and then implanted in uterus for growth and development.

Pteris, a pteridophyte, do not have free-living independent existence in their male and female gametophytes.

Any ovular structure associated with directing the growth of pollen tube toward the micropyle is generally referred to as obturator.

In angiosperms, meiosis in the sporophyte generation produces two kinds of spores.
Microspores

• It develops in the microsporangium
• Microsporangium germinate and develop into the male gametophyte generation 

Megaspores

• It develops in the megasporangium 
• Megasporangium will develop into the female gametophyte generation.

Development of megaspores: The nucleus of the megaspore undergoes 3 successive mitotic divisions. The 8 nuclei that result are distributed and partitioned off by cell walls to form the embryo sac, mature female gametophyte generation.

The ovum is in the secondary oocyte stage before it is released into the fallopian tube from the ovary. It is arrested in meiosis II of metaphase. Thus when the uterus is building up the endometrial tissue prior to ovulation, the ovum completes the metaphase of the meiosis II stage.