AIIMS Zoology Human Reproduction Class 12 Questions

Which of the following are homosporous

Choose the correct option

Choose the correct

Choose the correct one

Assertion : Parturition is induced by neural signal in maternal pituitary.

Reason : At the end of the gestation period, the maternal pituitary releases prolactin which cause uterine contractions.

Ploidy level of Nucellus, endosperm, polar nuclei, Megaspore mother cell, female gametophyte respectively are

Which hormone helps in detection of pregnancy?

Which of the following condition is true at the time just after ovulation?

Fibroid (leiomyoma) uterus is a-

Meiosis II in ovum doesn't completes until –

Assertion: Organism that reproduce by binary fission are immortal Reason: Such organism have special kind of rejuvenation capability.

Assertion: In females, parturition occurs after the pregnancy. Reason: Signal for parturition originates from fully developed embryo.

Gemmule formation is a common mode of asexual reproduction in

Read the Assertion and Reason carefully to mark the correct option from those given below Assertion Endosperm is formed by the fusion of one male gamete and two polar nuclei. Reason In pea, the endosperm remains the part of seed as it is not completely used up during embryo development.

The fluid which is rich in calcium èbrinolysin and acid phosphatase and contributes about 30% of the total volume of semen, is released by

Read the Assertion and Reason carefully to mark the correct option from those given below Assertion The technique shown in the given figure is frequently used in prenatal disease treatment. Reason This technique cannot be used for sex-determination of child.

Which of the following are homosporous pteridophytes? I. Selaginella II. Lycopodium III. Salvinia IV. Equisetum

Which of the following statements is correct regarding menstrual cycle?

Assertion: Foetal disorders can be diagnosed by chorionic villi sampling. Reason: Karyotyping can be done for mitotically dividing cells of chorionic villi.

Pollination in Rafflesia is occurred by

Elater mechanism for seed dispersal is exhibited by

In which of the following sets of organisms, does the external fertilization occur?

Starting from the maximum, arrange the following male reproductive accessory organs in the correct order, based on the amount of secretion poured into urethra. (i) Prostate gland (ii) Seminal vesicle (iii) Bulbourethral gland

Occurrence of triploid (3n) primary endosperm nucleus is a characteristic feature of

The pollen grains of rice and wheat lose their viability in ___ minutes of their release.

After double fertilization, a mature ovule has

Assertion: A mutual exchange of sperms occurs between two earthworms during mating. Reason: Mature sperms and egg cells and nutritive fluid are deposited in cocoons produced by gland cells of clitellum.

Assertion: In a regular medical examination of a small population, a 35 years old lady was found to have higher levels of oestrogens, progesterone in her blood. Reason: The lady is 12 weeks pregnant.

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: