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All of the following are true of gametes except
The stage during which menstruation stops in the adult female is
In centrolecithal eggs, the cleavage is
Polar body is produced during the formation of
Polar body is a small degenerate cell that forms after during oogenesis. During meiosis, the first polar body is formed when the secondary oocyte is formed. The polar bodies do not take part in fertilization.
Which of the following develops from endoderm?
So the correct answer is 'Liver, pancreas and thymus/thyroid.'
The mammalian follicle was first described by
Placenta in human beings is formed by
Which of the following hormones initiate parturition?
So the correct option is 'ACTH, corticosteroid, oxytocin'.
Testosterone is secreted by____.
Testosterone is produced by the gonads (by the Leydig cells in testes in men and by the ovaries in women), although small quantities are also produced by the adrenal glands in both sexes. It is an androgen, meaning that it stimulates the development of male characteristics.
Fertilisation takes place in the
Seminal plasma, the fluid part of semen, is contributed by
(i) seminal vesicle
(iv) bulbourethral gland
Seminal plasma is the fluid part of semen and is contributed by seminal vesicles, prostate gland and bulbourethral glands. Seminal vesicles contribute fructose, citric acid and other nutrients as well as fibrinogen and prostaglandin. Secretions from prostate gland contain calcium ions, phosphate Ion, etc. and are alkaline in nature. Bubo urethral glands secrete alkaline mucus which is important for the lubrication of penis.
Development of secondary sexual characters in females are controlled by
Fixing up of blastocyst in the wall of the uterus is
The signals for parturition originate from
Human eggs are
In general eggs of mammals have a little yolk. The human egg is alecithal meaning it is totally devoid of yolk. Hence, the human zygote gets implanted in the uterus of female and the egg or zygote is not laid. Humans are viviparous and females give birth to young ones.
Oogenesis occurs in the outermost layers of the ovaries. Oogenesis starts with a germ cell called oogonium and undergoes mitosis to increase in number. The process of oogenesis takes place in the following three stages: Pre-natal.
Ovulation in the human female normally takes place during the menstrual cycle
After ovulation Graafian follicle regresses into
Immediately after ovulation, the mammalian egg is covered by a membrane known as
If mammalian ovum fails to get fertilised, which one of the following is unlikely?