Biology MCQs for Class 12 with Answers Chapter 2 (Reproduction in Lower and Higher Animals)

Multiple choice questions.
1. The number of nuclei present in a zygote is ……
    a. two 
    b. one 
    c. four   
    c. eight

Answer : a 
Explanation - Ovum (female gamete) and sperm (male gamete) are both haploid (n) entities. Zygote is formed by fertization. i.e. fusion of male and female gametes. Thus, in zygote male and female gametes combine together to form diploid (2n) zygote.
Ovum(n) + Sperm(n) => Zygote (2n)

2. Which of these is the male reproductive organ in human?
    a. sperm 
    b. seminal fluid
    c. testes 
    d. ovary

Answer : c.
Explanation : The main male sex organs are the penis and the testicles (testes) which produce semen and sperm, which, as part of sexual intercourse, fertilize an ovum in the female's body; the fertilized ovum (zygote) develops into a fetus, which is later born as an infant.

3. Attachment of embryo to the wall of the uterus is known as……..

    a. fertilization 
    b. gestation
    c. cleavage 
    d. implantation

Answer : d 
Explanation : In humans, implantation is the stage of pregnancy at which the embryo adheres to the wall of the uterus. At this stage of prenatal development, the conceptus is called a blastocyst. It is by this adhesion that the embryo receives oxygen and nutrients from the mother to be able to grow.

4. Rupturing of follicles and discharge of ova is known as ..............

    a. capacitation 
    b. gestation
    c. ovulation 
    d. copulation

Answer : c
Explanation : Rupturing of Graafian follicles to release the secondary oocyte (ovum) from the ovary is called ovulation. In other words, ovulation is the release of a mature egg from the ovary.

5. In human female, the fertilized egg gets implanted in uterus ......................

    a. After about 7 days of fertilization
    b. After about 30 days of fertilization
    c. After about two months of fertilization
   d. After about 3 weeks of fertilization.

Answer : a 
Explanation : The fertilised egg or zygote undergoes several divisions to form the embryo. It moves into the uterus within a period of 4-5 days. In the uterus, the embryo implants itself into the endometrial lining 7-8 days after fertilisation. After implantation, it secretes a hormone called human chorionic gonadotrophin (hCG) which helps maintain the pregnancy. 
Thus, the correct answer is option a.

6. Test tube baby technique is called.........

    a. In vivo fertilization
    b. In situ fertilization
    c. In vitro fertilization
    d. Artificial insemination

Answer : c ( In vitro fertilization )

7. The given figure shows a human sperm. Various parts of it are labelled as A, B, C, and D .Which labelled part represents acrosome ?

Answer : d 

Explanation : 
    A denotes for Acrosome
    B denotes for Nucleus
    C  denotes for centriole
    D denotes for Mitochondria

8. Presence of beard in boys is a ............

    a. primary sex organ
    b. secondary sexual character
    c. secondary sex organ
    d. primary sexual character.

Answer : b ( secondary sexual character )