Biology · Science General

Botany and Plant Science

5,038 Questions

Botany and plant science delve into the biological study of plant life, covering structural anatomy, physiological processes, and reproductive mechanisms. Key topics include inflorescence patterns, root modifications, and seed development, which are vital for biology sections in medical entrance exams. This collection of practice questions helps solidify understanding of complex plant functions.

Plant ReproductionPlant AnatomyRoot ModificationsInflorescence PatternsPlant Morphology

Botany and Plant Science Questions

Multiple choice botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

An angiospermic plant has to produce $88$ viable embryo sacs. How many meiotic divisions will be needed to produce equal number of female gametophytes by this plant?

  1. $88$
  2. $22$
  3. $44$
  4. $132$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Ovule contains the female gametophyte or the embryo sac. Each ovule usually contains only one embryo sac
Each embryo sac is formed by meiotic division of the diploid mother cell
The end result of a meiotic division is 4 haploid cells, in most cases, of the 4 haploid cells formed, three degenerate and  one develops into the embryo sac 
Therefore, to produce 88 viable embryo sacs 88 meiotic divisions are required
So, the correct answer is '88'
Multiple choice botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

The female reproductive system produces haploid (n) gametes called ............. or egg cell.

  1. Ovum

  2. Endosperm

  3. Pollen grains

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

A. Female gametes are also called eggs or ovum. They are created during the cellular reproduction process known as meiosis. The resulting gamete cell is a haploid cell.

B. The endosperm is a tissue produced inside the seeds of most of the flowering plants following fertilization, It surrounds the embryo and provides nutrition.
C. pollen grains are the granular microspores that occur in pollen and give rise to male gametophyte of a seed plant and they are haploid.
D. The synergids are part of the egg apparatus and are thought to help the pollen nucleus reach the egg cell for fertilization.
So, the correct answer is "ovum".

Multiple choice botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

Androphore is lightly differentiated in the flower of .................

  1. $Rafflesia$
  2. $Calycanthus$
  3. $Salvia$
  4. $Passiflora$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

When in a flower, the internode between the corolla and the androecium is lengthened so as to raise the androecium high up in the air then that internode is called Androphore. It is an extension of the receptacle carrying the androecium and the gynoecium, typical of the caper family. In Passiflora, androphore is lightly differentiated.

Multiple choice botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

When pollen tube enters through the base of a funiculus or the integument the phenomenon is known as

  1. Porogamy

  2. Chalazogamy

  3. Mesogamy

  4. Isogamy
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When pollen tube enters through the micropyle, the phenomenon is known as porogamy. When pollen tube enters to the embryo sac through the tissue of the chalaza, the phenomenon is known as chalazogamy. When pollen tube enters through the base of a funiculus or the integument, the phenomenon is known as mesogamy. Isogamy is a form of sexual reproduction that involves fusion of gametes of similar size and structure. 

Thus, the correct answer is option C.

Multiple choice botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

Ovule is comparable to ............

  1. Megasporangium

  2. Microsporangium

  3. Microsporophyll

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

Ovule means 'small egg'. In seed plants, the ovule is the surface that gives rise to and contains the female reproductive cells. It consists of three parts: the integuments form its outer layers, the nucellus and female gametophyte in its center. The female gametophyte specifically termed as megagametophyte is also called the embryo sac in angiosperms.

Multiple choice botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

Nurse tissue of ovule is .............

  1. Nucellus

  2. Chalaza

  3. Hilum

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

The mature ovule contains in its central part a region called the nucellus that in turn contains an embryo sac with eight nuclei, each with one set of chromosomes. The two nuclei near the centre are referred to as polar nuclei. In the pines, the female gametophyte develops within the tissues of the nucellus and acquires abundant food reserves. The proembryo forms after a period of free-nuclear division in the zygote, and the tier of cells above the basal four then elongates to form a suspensor which pushes the embryonic group deep into the gametophyte.

Multiple choice botany plants: structure and function structure of male and female reproductive structures structure of ovule gynoecium

The megasporangium of the angiosperms on fertilization gives rise to

  1. A fruit

  2. Seed

  3. An embryo

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

The nucellus is a part of the inner structure of the ovule, forming a layer of diploid (sporophytic) cells inside the integuments. It is structurally and functionally equivalent to the megasporangium. In some plants, the diploid tissue of the nucellus gives rise to a seed through a mechanism of asexual reproduction called nucellar embryony.

So, the correct answer is 'seed'

Multiple choice botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

The point at which funiculus touches the ovule is

  1. Chalaza

  2. Hilum

  3. Raphe

  4. Endothelium
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
•Chalaza is portion of the ovule which is opposite to the region of attachment of nucellus, integuments and funiculus.
•Hilum is a structure by which body of ovule is attached to the funiculus. 
•Raphe is a ridge showing the fusion of funiculus with the body of ovule.
•Endothelium is a specialized tissue present around the embryo sac which is formed by the specialization of integuments to perform the nutritive function of nucellus in the ovules in which nucellus degenerates at an early stage.
So, the correct answer is B.
Multiple choice botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

Out of linear tetrad which one is the functional megaspore

  1. Micropylar

  2. Any of the middle ones

  3. Chalazal

  4. Any of the four
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Megaspore mother cell undergoes meiosis to form four haploid megaspores which are arranged in a linear tetrad. Out of these four megaspores, only one remains functional that develops into embryo sac or the female gametophyte and the rest three degenerate. The megaspore that remains functional can either be micropylar or chalazal depending upon the species. For example, in Polygonum, chalazal megaspore is functional while in Oenothera, micropylar megaspore is functional. Since Polygonum type embryo sac is the most common type of embryo sac found in Angiosperms, the functional Megaspore is generally the chalazal one. 
So, the correct answer is C.
Multiple choice botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

Orthotropous ovules occur in

  1. Pisum sativum

  2. Solanum nigrum

  3. Polygonum

  4. Helianthus
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Orthotropous ovule is the simplest and primitive type of ovule. In this type of ovule, micropyle, chalaza and funiculus lie in one vertical plane. Example of plants with orthotropous ovules are, Polygonum, Piper nigrum, Piper betel and all gymnosperms.
So, the correct answer is C.

Multiple choice botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

A mass of parenchymatous tissue forming the bulk of ovule is

  1. Obturator

  2. Female gametophyte

  3. Nucellus

  4. Endosperm
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Obturator is a structure of ovule that is associated with directing the growth of pollen tube towards the micropyle. It may originate either from the placenta or funiculus or even both.
Female gametophyte is the embryo sac. It is a 7-celled structure consisting of egg apparatus (comprising of egg cell and two synergids), a large central cell and three antipodal cells.
Nucellus is the central part of ovule in which embryo sac is present. It is a mass of parenchymatous cells and forms the major part of the ovule. 
Endosperm is the nutritive structure formed from triple fusion that provides nutrition to the developing embryo.
Hence, from all the options given in the question, the mass of parenchymatous cells forming bulk of ovule is nucellus.
So, the correct answer is C.
Multiple choice botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

Secondary nucleus formed by the fusion of two polar nuclei is also called

  1. Vegetative nucleus

  2. Definitive nucleus

  3. Generative nucleus

  4. Primary endosperm nucleus
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
The secondary nucleus formed by the fusion of two polar nuclei is also called definitive nucleus. Vegetative nucleus and Generative nucleus are present in the young pollen grain when the Microspore divides mitotically to form a large vegetative cell and a small generative cell. Primary endosperm nucleus is formed by the fusion of male gamete with a diploid secondary nucleus.
So, the correct answer is B.