Tag: modes of reproduction

Questions Related to modes of reproduction

Syngamy can occur outside the body of organisms in

  1. Algae

  2. Ferns

  3. Fungi

  4. Mosses


Correct Option: A
Explanation:

Syngamy is sexual reproduction by fusion of male gamete( sperm) with female gamete ( egg ) to form a zygote which eventually develops in the new organism.

In algae, the fusion of gametes happens outside the body of a plant, in water. The gametes are single cells without any protection. In all other plants, the fusion of gametes occurs inside the parent body and zygote is protected by the embryo.

In sexual reproduction of algae fusion between one large, non-motile (static) female gamete and a smaller motile male gamete is termed as

  1. Isogamous

  2. Anisogamous

  3. Oogamous

  4. None of these


Correct Option: C
Explanation:

The fusion of similar motile gametes is known as isogamous.

The motile gametes taking part in fusion may either differ in size or physiological behaviour is known as anisogamous.
Oogamous is a condition of heterogamy where one gamete is large and nonmotile, while the other is small and motile. In sexual reproduction of algae fusion between one large, non-motile (static) female gamete and a smaller motile male gamete is termed as oogamous. The large non-motile female egg fuses with male gamete which is motile and it is known as antherozoid. 
So, the correct answer is option C.

Process of sexual reproduction which involves meiosis and syngamy is

  1. Apomixis

  2. Amphimixis

  3. Agamospermy

  4. Diplospory


Correct Option: B
Explanation:
The process of fusion between haploid male nucleus and egg nucleus is known as amphimixis. It is also known as syngamy. The process is known as fertilization which leads to formation of a diploid zygote. It leads to the recombination of character which causes variation. It is a mode of sexual reproduction. The haploid gametes are formed by meiosis.
Apomixis is a mode of asexual reproduction. The development of plants takes place without fusion of gametes. The embryo develops without the fertilization of seeds. It is a powerful tool which fixes heterosis. The developed seeds are clones of plant. The ovule undergoes meiosis and forms aposporous initial cells which forms meiosis. It involves only meiosis not syngamy. 
Agamospermy is asexual reproduction in which seeds are produced from unfertilized ovules. The removal of the anthers of a flower in order to prevent self-pollination is known as emasculation. 
In diplospory, the megagametophyte arises from a cell of the archesporium.
So, the correct answer is option B.

Fertilization is fusion of

  1. Diploid spermatozoan with diploid ovum to form a diploid zygote

  2. Haploid spermatozoan with diploid ovum to form a diploid zygote

  3. Diploid spermatozoan with haploid ovum to form a diploid zygote

  4. Haploid spermatozoan with haploid ovum to form a diploid zygote


Correct Option: D
Explanation:

Fertilization is the process of union of a haploid sperm cell with haploid ovum to form a diploid zygote.

So the correct answer is 'Haploid spermatozoan with haploid ovum to form a diploid zygote.'

Fertilization was discovered by

  1. Strasburger

  2. Robert Brown

  3. Lamarck

  4. Darwin


Correct Option: A
Explanation:

Fertilization is the process of formation of the zygote by the fusion of male and female gamete. It was discovered by Strasburger. Lamarck and Darwin worked on the theories of evolution and Robert Brown discovered the nucleus.

So, the correct option is  'Strasburger'

Fusion of male and female gametes is termed as-

  1. Reproduction

  2. Vegetative propagation

  3. Cell-division

  4. Respiration.


Correct Option: A

When will sex determination in human take place?

  1. During fertilization

  2. When fertilised ovum takes place

  3. During sexual intercourse

  4. During fission of unfertilised egg


Correct Option: A
Explanation:

Chromosomal sex determination is carried out at fertilisation. This is done based on the presence or absence of the Y chromosome. Either the X or Y chromosome from the sperm fuses with the X chromosome of the egg and so females have XX and males have XY. So, the correct option is 'During fertilization'.

Fertilization can be correctly defined as fusion of

  1. Male and female pronuclei.

  2. Cytoplasm of male and female gametes.

  3. Two gametes.

  4. Male and female gametes of the same species.


Correct Option: D
Explanation:

Sexual reproduction is a characteristic of animals, although many animals reproduce sexually as well asexually. Reproduction is essential to the survival of any species. Most animals are involved in some variety of sexual reproduction. The methods vary greatly from the simultaneous release of sperm and eggs into the water for many marine organisms, to fertilization inside the body for most terrestrial organisms and high degrees of parental care in birds and mammals.

Fertilization is defined as a process of fusion of male and female gametes. The gametes are special haploid cells. The most widely accepted definition of species is the biological species- according to which members of same species alone can carry on the process of sexual reproduction (including fertilization) and produce fertile offspring.

Type of fertilization (external or internal) depends on

  1. Structure of egg

  2. Site of embryo development

  3. Type of sperm

  4. Both A and B


Correct Option: D
Explanation:

Aquatic animals like fishes and amphibia usually show external fertilisation, whereas terrestrial animals like reptiles, birds and mammals show internal fertilisation. Egg of animal showing external fertilization is not covered by a hard, protective shell and after fertilisation the embryo develops into larva in water. 

In terrestrial birds and reptiles the egg is covered with a hard, protective shell and development of embryo occurs inside egg. In mammals the egg is not covered by protective shell and fertilization is internal. After fertilization the zygote forms within the body of female animal and stays there till the formation of embryo.

If cowper's gland is removed, which of the following will be affected?

  1. Sexual attraction

  2. Fertilization

  3. Hardness of penis

  4. Copulation


Correct Option: B
Explanation:

In human males the urethra, a tube that exits through the penis, carries urine to the exterior and, alternatively, serves as a conduit for seminal fluid. Sperm is carried in a fluid formed along the male reproductive tract by the seminal vesicles, prostate gland, and cowper's glands, accessory glands of the male reproductive tract. Thus, if cowper's glands are removed process of fertilization will be affected.