Biology Human Reproduction

How is the sperm cell adapted to its function?

The acrosome in the head of a sperm cells contains digestive enzymes so a sperm can penetrate the egg. The mid piece is packed with mitochondria to release energy needed to swim and fertilise egg. Has a tail which enables sperm to swim

How is the egg adapted to its function?

The cytoplasm of an egg cell contains stores of energy which provide energy for the dividing of the zygote after fertilisation. The egg cell has jelly like coating which changed after fertilisation to form an impenetrable layer to prevent any other sperm cells entering the egg cell

Role of oestrogen in menstrual cycle?

Oestrogen levels rise from day 1-14 in the menstrual cycle to cause the uterus to develop a lining which was lost from menstruation

Role of progesterone in menstrual cycle?

Progesterone levels rise on day 14 which is ovulation to maintain and thicken the lining of the uterus. If fertilisation doesn’t happen, levels drop and menstruation occurs. Progesterone also inhibits FSH and LH production

Role of LH in menstrual cycle?

LH levels peak at day 14 which is ovulation to stimulate ovulation by releasing an egg into oviduct

Role of FSH in menstrual cycle?

FSH levels are constant through out but peak on day 14 which is ovulation. Its role is to stimulate egg maturation and stimulates follicles in ovaries to secrete oestrogen

What is the role of the placenta in the nutrition of developing embryo?

In the placenta, the mother’s blood comes very close with the blood of the developing embryo, but never mixes. The umbilical cord connects the embryo’s blood and the placenta, and the placenta allows molecules which the embryo needs to grow to diffuse from the Mother’s blood into the foetus’ blood, or for some substances active transport may be used. The waste products of the embryo such as CO2 or urea are also absorbed into the mother’s blood.

How is the placenta adapted to its function?

The placenta has a large surface are and thin wall to increase the rate of diffusion

What is the role of the amniotic fluid?

The amniotic fluid surrounds the developing embryo during pregnancy with a thin wall, which protects the embryo and the umbilical cord from any physical trauma