Science (English Medium) Class 12 - CBSE Question Bank Solutions

Which part of ovary in mammals acts as an endocrine gland after ovulation?

The second maturation division of the mammalian ovum occurs ______.

After birth, colostrum is released from mammary glands which is rich in ______.

Extra-embryonic membranes of the mammalian embryo are derived from ______.

Cleavage in mammalian egg is ______.

Choose the correct option:

Sterilisation techniques are generally fool proof methods of contraception with least side effects. Yet, this is the last option for the couples because:

1. It is almost irreversible
2. Of the misconception that it will reduce sexual urge/drive
3. It is a surgical procedure
4. Of lack of sufficient facilities in many parts of the country

Emergency contraceptives are effective if used within ______.

Choose the right one among the statements given below.

Condoms are one of the most popular contraceptives becuase of the following reasons.

The correct surgical procedure as a contraceptive method is ______.

Diaphragms are contraceptive devices used by the females.

Choose the correct option from the statements given below:

1. They are introduced into the uterus
2. They are placed to cover the cervical region
3. They act as physical barriers for sperm entry
4. They act as spermicidal agents

Which one is correct for mammalian testis?

The net electric charge on DNA and histones is ______.

Nucleosome core is made of ______.

Barr body in mammals represents ______.

In oocyte secondary maturation occurs in ______.

Which of the following is correct about mammalian testes?

Lower narrow end of uterus is called ______.

Bartholin’s glands are situated ______.

Structure connecting the fetus to placenta is ______.