Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions for Biology

Which one is released from the ovary?

During oogenesis, each diploid cell produces ______.

In oogenesis haploid egg is fertilised by sperm at which stage?

Layers of an ovum from outside to inside is ______.

Which of the following is a primary sex organ of female?

Head of epididymis is called as ______.

Which of the following are called dual gland?

The prostate gland and seminal vehicle perform the function of ______.

After the release of the secondary oocyte, the Graafian follicle develops into ______.

Mark the odd one.

Penetration of the sperm in the ovum is followed by ______

Read the following and answer from given below:

Oogenesis is the process of the formation of an ovum in the ovaries. It consists of three phases: multiplication, growth, and maturation. Oogenesis is controlled by hormones GnRH, LH, FSH. GnRH secreted by the hypothalamus stimulates the anterior lobe of the pituitary gland to secrete LH and FSH.

Which cell division is involved in the formation of secondary oocytes?

A patient admitted in ICU was diagnosed to have suffered from myocardial infarction. The condition of coronary artery is depicted in the image below.

Name two bioactive agents and their mode of action that can improve this condition.

α - 1 antitrypsin is ______.

How much of the net primary productively of a terrestrial ecosystem is eaten and digested by herbivores?

Indicate the stages where meiosis and mitosis occur (1, 2 or 3) in the flow chart.

The spermatogonia undergo division to produce sperms by the process of spermatogenesis. Choose the correct one with reference to above.

The mother germ cells are transformed into a mature follicle through series of steps. Provide the missing steps in the blank boxes.

During reproduction, the chromosome number (2n) reduces to half (n) in the gametes and again the original number (2n) is restored in the offspring. What are the processes through which these events take place?

What is the difference between a primary oocyte and a secondary oocyte?