IGCSE Biology Paper-2: Specimen Questions with Answers 144 - 145 of 203

Question 144

Question MCQ▾

Where does fertilization occur in humans?

Choices

Choice (4)

a.

Inside ovary

b.

Inside vagina

c.

Inside fallopian tube

d.

Inside uterus

Edit

Answer

c.

Explanation

Fertilization

  • Definition: The fusion of the haploid male gamete (the sperm) and the haploid female gamete (the ovum) to form a diploid zygote is called fertilization.
  • In human beings, fertilization takes place mostly in the ampulla of the oviduct. After insemination (i.e.. discharge of semen in the female vagina close to the cervix) , the sperms travel all the way up towards the uterus but only a few thousand find their way into the openings of the fallopian tubes.
  • Primarily the contractions of the uterus and the fallopian tubes assist the sperm in movement but later on, they move by their own motility. Sperms swim in the fluid medium at the rate of 1.5 to 3 mm per min to reach the site. In the meantime, the leucocytes of the vaginal epithelium also engulf millions of the sperms.
Inside Fallopian Tube

Question 145

Question MCQ▾

Which of the following graph shows the effect of increasing temperature on the rate of diffusion?

Choices

Choice (4)

a.

The Rate of Diffusion

b.

The Rate of Diffusion

c.

The Rate of Diffusion

d.

The Rate of Diffusion
Edit

Answer

c.

Explanation

Diffusion

  • The movement of molecules of gases, Liquid solid from the region of higher concentration to the region of lower concentration is called diffusion.
  • Process of Diffusion is based on kinetic energy of molecules. The molecules move from the higher concentration to lower concentration due to kinetic energy until an equilibrium is obtained. Ex: Diffusion of copper, sulphate particles in water, Diffusion of Ammonia in air.
Factor Affecting the Rate of Diffusion
  • Temperature: Rate of diffusion is directly proportional to temperature. If temperature increases than the rate of diffusion is increased.
  • Rate of diffusion Temperature.