Tag: fertilization in organisms

Questions Related to fertilization in organisms

In oogamy fertilisation involves,

botany modes of reproduction fertilization in organisms sexual reproduction in organisms reproduction in organisms

  1. A small non-motile female, gamete and large motile male gamete

  2. A large non-motile female gamete, and a small motile male gamete

  3. A large non-motile female gamete and a small non-motile male gamete

  4. A large motile female gemete and a small non-mbtile male gamete.

Show answer
Correct Option: B
Explanation:

In oogamy, fertilization involves the fusion of a large non-motile female gamete and a small motile male gamete. The large motile female gamete is the ovum which is produced in the ovary. The ovum after maturation is released from the ovary under the influence of LH hormone. The small motile male gametes are known as sperm which is produced in the testis. The two dissimilar gametes fuse to form a diploid zygote by the process of syngamy.

So, the correct answer is option B.

Fusion of dissimilar gametes is

botany modes of reproduction fertilization in organisms sexual reproduction in organisms reproduction in organisms

  1. Allogamy

  2. Dichogamy

  3. Autogamy

  4. Fertilization

Show answer
Correct Option: D
Explanation:
Cross-pollination in a crop plant is known as allogamy. Allogamy is defined as fertilization of ovum of a flower by the pollen of another flower on the different plant. The pollen is transferred from the anther of a male flower to the stigma of a female flower. Allogamy takes place because of the male and female part of a particular flower mature at a different time. 
Dichogamy is a condition when the stamens and pistils of a flower mature at different times to prevent self-fertilization.
Autogamy is the phenomena of fusion of gametes produced from the same individual. It involves the transfer of pollen from the anther to the stigma of the same flower. It is avoided when the number of seed is less, or the produced pollen is not able to fuse and germinate with the ovule of the same flower or the produced pollen are not healthy. 
Fusion of dissimilar gametes is fertilization. It takes place during sexual reproduction where the male and female gametes fuse to form a zygote. 
So, the correct answer is option D.

Regarding fertilization which among the following statements is incorrect

botany modes of reproduction fertilization in organisms sexual reproduction in organisms reproduction in organisms

  1. It restores diploid condition in the zygote

  2. It activates egg both physiologically and metabolically

  3. Paternal and maternal sets contribute to the diploid number without causing any variation

  4. It determines the sex of the offspring

Show answer
Correct Option: C
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 and restores diploid condition in zygote. The statement is true.

Fertilization activates the egg physically and leads to formation of fertilization cone to prevent polyspermy. It also brings changes in permeability. The eggs become metabolically active and allows division of nucleus and forms embryo. The statement is true.
Sexual reproduction leads to the recombination of character in the pachytene stage of the meiosis which causes variation. So, the statement is false.

Fertilization determines the sex. Men have an X and a Y. So, each of their sperm carries one of the 2 sex chromosomes, which sex chromosome is in the sperm that fertilizes the egg dictates the baby's sex. The statement is true.

So, the correct answer is option C.

Syngamy can occur outside the body of organisms in

botany modes of reproduction fertilization in organisms sexual reproduction in organisms reproduction in organisms

  1. Algae

  2. Ferns

  3. Fungi

  4. Mosses

Show answer
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

botany modes of reproduction fertilization in organisms sexual reproduction in organisms reproduction in organisms

  1. Isogamous

  2. Anisogamous

  3. Oogamous

  4. None of these

Show answer
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

botany modes of reproduction fertilization in organisms sexual reproduction in organisms reproduction in organisms

  1. Apomixis

  2. Amphimixis

  3. Agamospermy

  4. Diplospory

Show answer
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

botany modes of reproduction fertilization in organisms sexual reproduction in organisms reproduction in organisms

  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

Show answer
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

botany modes of reproduction fertilization in organisms sexual reproduction in organisms reproduction in organisms

  1. Strasburger

  2. Robert Brown

  3. Lamarck

  4. Darwin

Show answer
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-

botany modes of reproduction fertilization in organisms sexual reproduction in organisms reproduction in organisms

  1. Reproduction

  2. Vegetative propagation

  3. Cell-division

  4. Respiration.

Show answer
Correct Option: A

When will sex determination in human take place?

botany modes of reproduction fertilization in organisms sexual reproduction in organisms reproduction in organisms

  1. During fertilization

  2. When fertilised ovum takes place

  3. During sexual intercourse

  4. During fission of unfertilised egg

Show answer
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'.