AIIMS Zoology Human Reproduction Class 12 Questions

The 'cells of Rouget' are

Choose the correct statement.

Assertion: A male is found to be lacking facial hair and pubic hair. Reason: It is a case of hyposecretion of testosterone from Leydig's cells of testes.

Which of the following statements is correct?

Assertion : Corpus luteum is produced by Graafian follicle after ovulation. Reason : It secretes estrogen which is necessary to maintain pregnancy.

What do A, B, C and D represent?

Which animal has the longest gestation period?

Assertion: Parturition is induced by neural signal in maternal pituitary. Reason: At the end of gestation period, the maternal pituitary release prolactin which causes uterine contractions.

Assertion: Commelina shows cleistogamy. Reason: This reduces chances of inbreeding.

In humans at the end of first meiotic division, the male germ cells differentiate into the

Upon fertilization, what structure develops from carpel?

Assertion: Mammalian ova produces hyaluronidase. Reason: The eggs of mammal are microlecithal and telolecithal.

Acrosome reaction in sperm is triggered by

How many sperms are formed from a secondary spermatocyte?

Which one of the following pairs of plant structures has haploid number of chromosomes?

Nicotiana sylvestris flowers only during long days and N. tabacum flowers only during short days. If raised in the laboratory under different photoperiods, they can be induced to flower at the same time and can be cross-fertilized to produce self-fertile offspring. What is the best reason for considering N. sylvestris and N. tabacum to be separate species?

Assertion: The primary protonema of moss by death and decay of cells may break into fragments. Reason: Each fragment gives rise to leafy gametophyte.

Assertion: Many plants are propagated vegetatively even though they bear seeds. Reason: Potatoes multiply by tubers and apple by cutting.

Which of the following is true regarding sperm?

A cross section at the midpoint of the middle piece of a human sperm will show

Which one of the following events is correctly matched with the time period in a normal menstrual cycle?

Both corpus luteum and macula lutea are:

The phase of menstrual cycle in humans that last for 7-8 days, is:

Which one of the following statements with regard to embryonic development in humans is correct?

Assertion : Holoblastic cleavage with almost equal sized blastomeres is a characteristic of placental animals. Reason : Eggs of most mammals, including humans, are of centrolecithal type.

Xenia and metaxenia terms are related with

An oocyte is released from the ovary under the influence of LH