Question

Write one sentence each using the following terms pertaining to reproduction in humans.

i) Gestation-

ii) 280 days-

iii) Headfirst-

iv) Placenta-

Answer 1

Hint: Reproduction is the ability of fertile living organisms to give birth to young ones so that life on earth goes on. There can be two kinds of reproduction, namely, Sexual Reproduction and Asexual Reproduction. 

Complete answer: 

i) Gestation- Gestation is the period of development during the carrying of an embryo or fetus inside viviparous animals. It is mainly observed in mammals but also occurs for some non-mammals.

ii) 280 days- 280 days is the date given to a woman that is likely to deliver a baby after the onset of their last menstruation.

iii) Headfirst- Headfirst is a position during the delivery of a baby where the head comes first along with the umbilical cord.

iv) Placenta- The placenta is a temporary organ that connects the developing fetus via the umbilical cord to the uterine wall to allow oxygen and nutrient uptake to the growing fetus. It also provides thermo-regulation, waste elimination, and gas exchange via the mother's blood supply; to fight against internal infection, and to produce hormones that are required for pregnancy.

Note: Some babies are also born prematurely which is before 280 days due to certain physiological or hormonal changes in the mother.

Placental hormones include members of the prolactin and growth hormone family, steroid hormones, and neuroactive hormones. Placenta produces hormones, namely, Progesterone, Estrogen, Human chorionic gonadotropin( HCG), and human placental lactogen during pregnancy.