Tag: botany

Quizzes (264) Questions (5276)

Questions Related to botany

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

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)
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In external fertilization, gametes are released into the medium (usually water) simultaneously to increase the chance of fusion. However, offspring are highly vulnerable to predators, meaning they do not have a better chance of survival.

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

Mark the correct one.

  1. Labeo- Internal fertilization

  2. Frog - Internal fertilization

  3. Birds - External fertilization

  4. Balaenoptera - internal fertilization
Reveal answer Fill a bubble to check yourself
D Correct answer
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'.
Multiple choice botany modes of reproduction fertilization in organisms sexual reproduction in organisms reproduction in organisms

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.
Reveal answer Fill a bubble to check yourself
C Correct answer
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.

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

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
Reveal answer Fill a bubble to check yourself
A Correct answer
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.

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

Isogamy is found in

  1. Hydra

  2. Monocystis

  3. Plasmodium

  4. Planaria
Reveal answer Fill a bubble to check yourself
B Correct answer
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.

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

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
Reveal answer Fill a bubble to check yourself
C Correct answer
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.

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

In oogamy fertilisation involves,

  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.
Reveal answer Fill a bubble to check yourself
B Correct answer
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.

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

Fusion of dissimilar gametes is

  1. Allogamy

  2. Dichogamy

  3. Autogamy

  4. Fertilization
Reveal answer Fill a bubble to check yourself
D Correct answer
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.
Multiple choice botany modes of reproduction fertilization in organisms sexual reproduction in organisms reproduction in organisms

Regarding fertilization which among the following statements is incorrect

  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
Reveal answer Fill a bubble to check yourself
C Correct answer
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.

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

Syngamy can occur outside the body of organisms in

  1. Algae

  2. Ferns

  3. Fungi

  4. Mosses
Reveal answer Fill a bubble to check yourself
A Correct answer
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.