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 know the plant world closely diversity in plants types of nutrition in plants different modes of nutrition in plants

The pertinacious substance involved in saprophytic incompatibility and stored in the exile is derived from ____________.

  1. Tapetum

  2. Microspore

  3. Anther locule

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

In flowering plants, the tapetum is the innermost layer of the anther wall that provides nutrients to developing microspores and contributes substances to the pollen wall, including those involved in self-incompatibility.

Multiple choice botany know the plant world closely diversity in plants types of nutrition in plants different modes of nutrition in plants

Which one of the following does NOT apply to saprophytic self-incompatibility systems?

  1. $3$-celled pollen

  2. Dry stigma

  3. Rejection reaction in the style

  4. In vitro pollen germination is difficult
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Sporophytic self-incompatibility is typically associated with 2-celled pollen at the time of shedding. 3-celled pollen is characteristic of gametophytic self-incompatibility systems.

Multiple choice botany know the plant world closely diversity in plants types of nutrition in plants different modes of nutrition in plants

Consider the following statements.
a. In insectivorous plants, trachoma's secrete digestive enzymes onto the trapped insects.
b. Suberin gives the strength and waterproofing properties to sclerenchyma.
c. Roots do not form a bark.
Which of the statements given is/are correct?

  1. $1$ only
  2. $1$ and $2$
  3. $2$ and $3$
  4. $3$ only
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice plant diseases keeping diseases away biology

Consider the following events.
a. Germ tube formation
b. Aspersoria formation
c. Penetration
d. Haustoria's formation.
The correct sequence in which these events take place during plant infection is?

  1. $2, 1, 4, 3$
  2. $2, 3, 1, 4$
  3. $1, 2, 3, 4$
  4. $1, 2, 4, 3$
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice botany modes of reproduction introduction to flower pre fertilization - plants sexual reproduction in flowering plants the origin of cells and cell division

In Casuarina, fertilization occurs by 

  1. Chalazogamy

  2. Mesogamy

  3. Porogamy

  4. Apogamy
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Pollen tube eventually reaches the micropyle of an ovule to enter the embryo sac and for this purpose, it may follow one of the following three routes:
  • 1. Porogamy- when the pollen tube enters the ovule through the micropyle. It is common for most of the angiosperms.
  • 2. Mesogamy- when the pollen tube enters through the integuments (Cucumber) or through funiculus (Pistacia).
  • 3. Chalazogamy- when the pollen tube enters through the chalazal tissues. For example, Casuarina.
Hence In Casuarina, fertilization occurs by Chalazogamy.
  • So, the correct answer is 'Chalazogamy'.
Multiple choice botany modes of reproduction introduction to flower pre fertilization - plants sexual reproduction in flowering plants the origin of cells and cell division

The phenomenon of pollen tube entering the ovule laterally through integuments is called

  1. Mesogamy

  2. Aporogamy

  3. Chalazogamy

  4. Vegetative fertilization
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
•Mesogamy is the entry of pollen tube through the integuments.
•Aporogamy is the condition in which pollen tube enters the ovule through a path other than micropyle.
•Chalazogamy is the entry of pollen tube through chalaza.
•Vegetative fertilisation is a part of double fertilisation in Angiosperms, in which one of the two male gametes fuses with the diploid secondary nucleus and this results in the formation of a triploid primary endosperm mother cell. It is also known as triple fusion.
So, the correct answer is A.
Multiple choice botany modes of reproduction introduction to flower pre fertilization - plants sexual reproduction in flowering plants the origin of cells and cell division

In Casuarina, fertilization takes place through

  1. Mesogamy

  2. Porogamy

  3. Chalazogamy

  4. Apogamy
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
• Mesogamy is the entry of pollen tube in the ovule through the integuments (e.g. Cucurbita) or through funiculus (e.g. Pistacia).
• Porogamy is the entry of pollen tube in the ovule through the micropyle. It occurs in most of the angiosperms.
• Chalazogamy is the entry of pollen tube in the ovule through the chalazal tissues. Example, Casuarina.
• Apogamy is a type of reproduction in which sporophyte develops directly from the gametophyte without the fusion of gametes.
Hence, in Casuarina fertilization takes place through Chalaza, as pollen tube enters the ovule from Chalaza to release the male gametes which will fuse with the egg cell and central cell, resulting in fertilization.
So, the correct answer is C.
Multiple choice botany modes of reproduction introduction to flower pre fertilization - plants sexual reproduction in flowering plants the origin of cells and cell division

In Angiosperms pollen tube liberate their male gametes into the : -

  1. Central cell

  2. Antipodal cells

  3. Egg cell

  4. Synergids
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
The contents of the pollen tube are discharged in the synergid from where the first male gamete is transferred to the egg cell, while the other male gamete moves to the central cell through cytoplasmic current. On reaching of pollen tube inside the embryo sac, the 2 male gametes are discharged through a subterminal pore in the pollen tube. The contents of the pollen tube are discharged in the synergid and the pollen tube does not grow beyond it in the embryo sac. Further, the cytoplasm of the pollen tube is restricted to the chalazal end of this synergid cell.

So, the correct answer is 'Synergids'.
Multiple choice botany modes of reproduction introduction to flower pre fertilization - plants sexual reproduction in flowering plants the origin of cells and cell division

Which one of the following was observed for the first time by Treub?

  1. Entry of pollen tube into the ovule through the micropyle in Casuarina.

  2. Entry of pollen tube into the ovule through the chalaza in Casuarina.

  3. Entry of pollen tube into the ovule through the integuments in Hibiscus.

  4. Entry of pollen tube into the ovule through the chalaza in Hibiscus.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • Casuarina equisetifolia is a monoecious, wind-pollinated species that undergoes chalazogamy fertilization.
  • In this type of fertilization, the pollen tube penetrates the ovule through the tissue of the chalaza.
  • It was first observed by Treub in 1981 in Casuarina species.
Multiple choice botany modes of reproduction introduction to flower pre fertilization - plants sexual reproduction in flowering plants the origin of cells and cell division

Number of male gemetes present in pollen tube are 

  1. 1

  2. 2

  3. 3

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

The pollen tube consists of two male gametes. One male gamete fertilizes the egg cell placed in between the egg apparatus and forms the diploid oospore/zygote which forms embryo after maturation. While the other male gamete fuses with the two polar nuclei of the central cell and forms the triploid PEN (Primary Endosperm Nucleus) which results in the formation of endosperm after maturation.

So, the pollen tube consists of 2 male gametes for the process of double fertilization to take place in angiosperm plants.
So, the correct answer is '2'.

Multiple choice botany modes of reproduction introduction to flower pre fertilization - plants sexual reproduction in flowering plants the origin of cells and cell division

Growth of pollen tube towards embryo sac is

  1. Geotropism

  2. Chemotaxis

  3. Phototaxis

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

Chemotaxis is the movement of an organism or plant in response to a chemical stimulus. Somatic cells, bacteria and other single cell or multicellular organisms direct their movements according to certain chemicals in their environment. It is clearly seen in the case of growth of pollen tube towards the embryo sac. The pollen tube does not directly reach the ovary in a straight line. It travels near the skin of the style and curls to the bottom of the ovary, then near the receptacle, it breaks through the ovule through the micropyle and the pollen tube bursts into the embryo sac.

Multiple choice botany modes of reproduction introduction to flower pre fertilization - plants sexual reproduction in flowering plants the origin of cells and cell division

If the integuments are pierced by the pollen tube during fertilization. 

It is reffered as ..................

  1. Porogamy

  2. Mesogamy

  3. Chalazogamy

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

In mesogamy, pollen tube enters the ovule through the integuments or funiculus. After the pollen tube enters the embryo sac, its apex dissolves and the male gametes are liberated. One of the male gametes are liberated. One of the male gametes fuses with the egg and produces a diploid zygote which by further division develops into an embryo. The other male gamete fuses with the diploid secondary nucleus and produces a triploid primary endosperm nucleus. This is called double fertilization.

Multiple choice botany modes of reproduction introduction to flower pre fertilization - plants sexual reproduction in flowering plants the origin of cells and cell division

Pollen tube releases sperms in ...

  1. Egg cell

  2. Antipodals

  3. Centre cell

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

Synergid cells are two specialized cells that lie adjacent to the egg cell in the female gametophyte of angiosperms and play an essential role in  pollen tube guidance and function. The term synergid comes from the Greek word ' Synergos' which means 'working together' and was reportedly coined by Eduard Strasburger. The pollen tube grows towards and into one of the synergid cells, which begins to degenerate as the pollen tube enters it. The pollen tube then ceases growth, ruptures and releases its two sperm cells which migrate to the egg and central cell, fertilization of which gives rise to the embryo and endosperm, respectively. The synergid cells are necessary for pollen tube guidance in the ovule.

Multiple choice botany modes of reproduction introduction to flower pre fertilization - plants sexual reproduction in flowering plants the origin of cells and cell division

Movement of pollen tube is

  1. Chemotropism

  2. Hydrotropism

  3. Phototropism

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Paratonic growth movements are the induced movements of growth, caused by external stimuli, such as gravity, light, water or contact. The movements show a directional relation to the stimulus. The stimuli are effective in causing growth movements only when they are unidirectional. Such movements are generally known as tropic movements and the phenomenon is referred to as tropism. 

Based on the nature of stimulus, tropisms may be of various types-
(A) Geotropism
(B) Phototropism
(C) Hydrotropism
(D) Chemotropism
(E) Thigmotropism
In flowering plants growth of pollen tube towards embryo sac is an example of chemotropism and occurs in response to chemicals secreted by synergids in embryo sac.