Advanced Animal Reproduction

The developing embryo does not receive nourishment from mother's body in oviparous reproduction.Oviparous animals are animals that lay eggs, with little or no other embryonic development within the mother. This is the reproductive method of most fish, amphibians, reptiles, all birds, the monotremes, and most insects, molluscs, and arachnids.

Semen includes sperms and secretions of accessory sex glands. It is also known as seminal fluid.

In mammals, the developing embryo is connected with placenta by umblical cord. During prenatal development, the umbilical cord is physiologically and genetically part of the fetus and, (in humans), normally contains two arteries (the umbilical arteries) and one vein (the umbilical vein), buried within Wharton's jelly.

Gestation period is the time between fertilisation and birth of the young ones.For most species, the amount a fetus grows before birth determines the length of the gestation period.

Oxytocin hormone helps in the ejection of milk from the breast. Oxytocin is normally produced in the hypothalamus and stored in the posterior pituitary gland.

The process by which blastocyst settles down on the uterine walls is known as blastulation.During blastulation, cells continue to divide and begin to differentiate.

The capsule enclosing testes of mammals is called tunica albuginea.The tunica albuginea helps to trap the blood in the corpora cavernosa, thereby sustaining erection of the penis.

The female sex hormone estrogen is produced by cells of graafian follicle.  Graffian Follicle is a fluid-filled structure in the mammalian ovary within which an ovum develops prior to ovulation.

When luteinizing hormone is injected into the body of adult males, more of testosterone is produced because testosterone produced is under the control of luteinizing hormone.

In unisexual reproduction, the union of male and female cells can take place outside the body, inside the body and in water in some cases.

 Embryology is the branch of biology that deals with the development of an embryo from the fertilization of the ovum to the fetus stage.

In gynadromorphs, as seen in Drosophila (fruit fly), one half of the body is male and the other half is female.

The middle piece of sperm provides energy.The midpiece has a central filamentous core with many mitochondria spiralled around it, used for ATP production for the journey through the female cervix, uterus and uterine tubes.

The ovum passes down the oviduct by influence of gravity. 

From 100 primary oocytes, the number of secondary oocytes formed is 200.

The reproductive cycle of animals and plants is characterised by the alternation of meiosis and fertilisation.

Asexual reproduction requires one individual.Asexual reproduction is a mode of reproduction by which offspring arise from a single organism, and inherit the genes of that parent only; it is reproduction which almost never involves ploidy or reproduction without the fusion of gametes.

The statement 'the breeding in birds is affected by light' is true.

Menstrual cycle includes proliferative phase (14 days), secretory phase (10 days) and menstrual phase (4 days). 

Test tube baby means that fertilisation is external and the subsequent development of zygote is internal.The process involves monitoring and stimulating a woman's ovulatory process, removing ovum or ova (egg or eggs) from the woman's ovaries and letting sperm fertilise them in a liquid in a laboratory. The fertilised egg (zygote) is cultured for 2–6 days in a growth medium and is then implanted in the same or another woman's uterus, with the intention of establishing a successful pregnancy.