Tag: fertilization in organisms

Questions Related to fertilization in organisms

Fusion of two gametes which are dissimilar in size is termed as

  1. Oogamy

  2. Isogamy

  3. Anisogamy

  4. Both A and C


Correct Option: D
Explanation:
In anisogamy the fusing gametes differ in size and behaviour. One of the two gametes is larger and is called macrogamete or female gamete; the other is smaller and is termed microgamete or male gamete. In oogamy, there is a large food laden non-flagellate female gamete called egg or oosphere whereas the male gamete or antherozoid is smaller and motile. Oogamy is the familiar form of sexual reproduction, it is a form of anisogamy (heterogamy).
So, the correct answer is 'Both A and C'.

Life begin in all sexually reproducing organisms as a

  1. Single-celled zygote

  2. Double-celled zygote

  3. Haploid zygote

  4. Haploid gametes


Correct Option: A
Explanation:
Zygote is the vital link that ensures continuity of species between organisms of one generation and the next. Every sexually reproducing organism, including human beings begin life as a single cell - the zygote. 

Following table summarises the differences between self-fertilisation and cross-fertilisation. Pick out the wrong difference.

  1. Self-fertilisation - It is uniparental, Cross-fertilisation - It is biparental

  2. Self-fertilisation - It involves the fusion of male and female gametes of the same parent, Cross-fertilisation - It involves the fusion of two gametes produced by different parents

  3. Self-fertilisation - Examples : Pheretima, Periplaneta, Cross-fertilisation - Examples : Taenia, Rana tigrina

  4. None of the above


Correct Option: C
Explanation:

Self-fertilisation occurs in Taenia, while cross-fertilisation occurs in Pheretima, Periplaneta and Rana tigrina.

Select the correct option:

On very special feature in the earthworm is that:

  1. fertilization of eggs occurs inside the body

  2. the typhlosole greatly increases the effective absorption area of intestine

  3. the S-shaped setae embedded in the integument are the defensive weapons used against the enemies

  4. it has a long dorsal tubular heart.


Correct Option: B
Explanation:

From 27th segment upt 23-25 segments in front of the anus in intestine of earthworm, lies a highly glandular and vascular part called typhosole. It greatly increases the effective absorption area for digested food in the intestine.

Given below are a few statements related to external fertilisation. Choose the correct statements.
(i) The male and female gametes are formed and released simultaneously.
(ii) Only a few gametes are released into the medium.
(iii) Water is the medium in a majority of organisms exhibiting external fertilisation.
(iv) Offspring formed as a result of external fertilisation have better chance of survival than those formed inside an organism.

  1. (iii) and (iv)

  2. (i) and (iii)

  3. (ii) and (iv)

  4. (i) and (iv)


Correct Option: B

Mark the correct one.

  1. Labeo- Internal fertilization

  2. Frog - Internal fertilization

  3. Birds - External fertilization

  4. Balaenoptera - internal fertilization


Correct Option: D
Explanation:
  • Balaenoptera which designates genus is a combination of two Latin words, Balaena (meaning whale) and "pteron" (meaning fin). It thus means a whale having a dorsal fin so as to distinguish from Balaena (meaning whale without dorsal fin). "Musculus" designating species is a Latin word originally meaning a "mouse.
  • In mammals, reptiles, birds, and some types of fish the gametes meet inside of the female's body. This is called internal fertilization. 
  • As Balaenoptera is a mammal the fertilization in Balaenoptera is internaL.
  • so, the correct answer is  'Balaenoptera - internal fertilization'.

Fertilization is

  1. Union of diploid spermatozoon with diploid ovum to form diploid zygote.

  2. Union of haploid sperm with haploid ovum to form haploid zygote.

  3. Union of haploid sperm with haploid ovum to form diploid zygote.

  4. Union of diploid sperm with haploid ovum to form triploid zygote.


Correct Option: C
Explanation:

Sexual reproduction in animals involves the production and fusion of two types of gametes (haploid cells) sperm and eggs. Typically, two different individuals are required. A male parent contributes sperm, and a female parent contributes an egg, or ovum. The sperm provides genes coding for some of the male parents traits, and the egg contributes genes coding for some of the female parents traits. The egg is typically large and nonmotile, with a store of nutrients that supports the development of the embryo. The sperm is usually small and motile and adapted to propel itself by beating its long, whip like flagellum. When sperm and egg unite, a (diploid) zygote, or fertilized egg, is produced. The zygote develops into a new animal, similar to both parents but not identical to either. Sexual reproduction typically involves remarkably complex structural, functional, and behavioural processes. In vertebrates, hormones secreted by the hypothalamus, pituitary gland and gonads regulate these processes.

When gamete fusion is involved in the formation of new organism the phenomenon is known as

  1. Syngamy

  2. External fertilization

  3. Parthenogenesis

  4. Parthenocarpy


Correct Option: A
Explanation:

Syngamy is a process in sexual reproduction that is defined as the fusion of the male gamete i.e., sperm with the female gamete i.e., egg resulting in the formation of a diploid zygote. Thus the correct answer is option A.

Isogamy is found in

  1. Hydra

  2. Monocystis

  3. Plasmodium

  4. Planaria


Correct Option: B
Explanation:

The fusion of similar motile gametes is known as isogamous. Monocystis is an endoparasite in the seminal vesicle and coelom of earthworms. Fusing gametes do not differ morphologically but may be different physiologically. The isogamous gametes fuses to form zygote which develops into sporoblast, sporocyst, trophozoite and finally, to young trophozoite.

So, the correct answer is option B.

In sexual reproducing animals, the union of male and female gamete forms a cell, which is called as

  1. Ovarian cell

  2. Oocyte

  3. Zygote

  4. Graafian follicle


Correct Option: C
Explanation:

Ovarian cell is the cells of ovary.
Oocyte is the female gametocyte or germ cell. It is involved in reproduction.
Zygote is the diplod cell, formed by the fusion of two gametes i.e., by the fusion of male gamete (sperm) or female gamete (ovum).
Graafian follicle is the mature follicle in the ovary of mammals. It contains cavity, which is filled by liquid and it ruptures during ovulation to release ovum.
Thus, the correct answer is option C.