Biology · Science General

Botany and Plant Science

4,989 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 male & female gametophytes: structure and development pollen grain androecium male gametophyte

Consider the following statements.
(i) Polyspermy may bring about fertilisation of egg by more than one male nucleus or the supernumerary sperms may fertilise other components of embryo sac such as synergids or antipodals.
(ii) In angiosperms, pollen tube is normally an unbranched structure which usually persists after fertilisation.
(iii) Intine is the inner, pectocellulosic layer of pollen grain wall which is destroyed during acetolysis.
(iv) Exine layer of pollen grain comprises of an outer non-sculptured layer sexine and an inner sculptured layer tectum.
Which of the following combinations of given statements is correct?

  1. (i) and (iv)

  2. (i) and (iii)

  3. (ii) and (iii)

  4. (ii) and (iv)
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Polyspermy refers to a situation where more than two sperms are released in an embryo sac. This may result because of the formation of more than two sperms in a pollen tube or due to the penetration of an embryo sac by more than one pollen tube. In angiosperms, the pollen tube is normally an unbranched structure which collapses soon after fertilization, the pollen tube may persist for as long as three weeks. Intine is the inner, more or less uniform, pectocellulosic layer of pollen grain wall, which is destroyed during acetolysis. Morphologically, the exine is divisible into two distinct layers: (i) an outer sculptured layer called sexine, and (ii) an inner non-sculptured layer, nexine. The sexine further comprises an internal layer of upright rod-like elements, the columellae(bacula) covered over by a roof-like layer, the tectum. The exine is, thus, typically33-layered consisting of tectum, columella, and nexine. The tectum may be smooth or have various types of processes.

So, the correct answer is '(i) and (iii)'.

Multiple choice botany male & female gametophytes: structure and development pollen grain androecium male gametophyte

Choose the correct answers from the alternatives given.
A pollen grain is best defined as a

  1. male gamete

  2. microspore mother cell

  3. partially developed male gametophyte

  4. partially developed embryo
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Each pollen grain is a minute body, of varying shape and structure, formed in the male structures of seed-bearing plants and transported by various means (wind, water, insects, etc.) to the female structures, where fertilization occurs. In angiosperms, pollen is produced by the anthers of the stamens in flowers.

So, the correct option is, 'partially develop male gametophyte'

Multiple choice botany male & female gametophytes: structure and development pollen grain androecium male gametophyte

Ubisch bodies found in tapetal cell helps in the formation of 

  1. Pollenkitt and pollinia

  2. Exine

  3. Intine and pollenkitt

  4. none of above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ubisch bodies found in tapetal cells help in pollen formation by participating in the external thickening of exine. They occur during spore wall formation and migrate to the cell cavity, where they are coated with sporopollenin and are released into the anther cavity. 

So, the correct option is 'Exine'.

Multiple choice botany male & female gametophytes: structure and development pollen grain androecium male gametophyte

A staminode does not contain ________.

  1. Anther

  2. Filament

  3. Male gametes

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

Staminode is the term used for the sterile stamen that does not make the pollen grain and appears like petals, as seen in Canna. 

A. Anther is the part of the stamen that contains the sporogenous tissue that produces pollen grains.
B. The filament is the part of the stamen that attaches the anther to the thalamus.
C. Male gametes are present within the pollen grain.
D. Pollen grains are the male gametophytes.
Hence, the correct answer is 'Pollen grains'.

Multiple choice botany male & female gametophytes: structure and development pollen grain androecium male gametophyte

Germ pore/ germinal furrow present on the surface of pollen grain represents

  1. Area where exine is thin or absent

  2. Specialised thickening of exine

  3. Specialised thickening of intine

  4. Area where tectum is absent
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Pollen wall consists of two layers: outer layer exine and inner layer intine.
Exine is made up of sporopollenin which is one of the most resistant known biological materials. Exine is thin in the beginning but it becomes very thick with maturity. However, exine is discontinuous or ruptured at some places. These are the called the germ pores (or germinal furrow) through which pollen tube comes out during germination on the stigma.
So, the correct answer is A.
Multiple choice botany male & female gametophytes: structure and development pollen grain androecium male gametophyte

The innermost layer of the anther wall is tapetum which

  1. helps in dehiscence

  2. provides mechanical support

  3. provides protection

  4. provides nutrition
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
The tapetum is a specialized layer of nutritive cells found within the anther, of flowering plants, where it is located between the sporogenous tissue and the anther wall. Tapetum is important for the nutrition and development of pollen grains, as well as a source of precursors for the pollen coat.
So, the correct option is, 'provides nutrition'.
Multiple choice biology reproduction in living organisms growth and development in plants sexual reproduction in plants post fertilization - plants

Mature ovary forms the

  1. Seed

  2. Stamen

  3. Pistil

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

Fruits are formed by the maturation of one or more ovary. Fruits contain seeds resulting from the maturation of fertilized ovules. However, maturation of seed and fruit can occur in the absence of fertilization. In fleshy fruits, the outer covering is called as pericarp. Pericarp is again made of three layers, the epicarp, which is the outermost layer; the mesocarp, which is the middle layer; and the endocarp, which is the inner layer surrounding the ovary or the seeds. 

So, the correct answer is option D.

Multiple choice biology reproduction in higher plants growth and development in plants sexual reproduction in plants post fertilization - plants

Which of the following is a post fertilisation event in flowering plants?

  1. Transfer of pollen grains

  2. Embryo development

  3. Formation of flower

  4. Formation of pollen grains
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Events in sexual reproduction after the fertilisation are called post-fertilisation events. After fertilisation, a diploid zygote is formed in all sexually reproducing organisms. The process of development of embryo from the zygote is called embryogenesis.
So, the correct answer is 'Embryo development'.
Multiple choice biology reproduction in higher plants growth and development in plants sexual reproduction in plants post fertilization - plants

In angiosperms, normally after fertilisation.

  1. The zygote divides earlier than the primary endosperm nucleus

  2. The primary endosperm nucleus divides earlier than the zygote

  3. Both the zygote and primary endosperm nuclei divide simultaneously

  4. Both the zygote and primary endosperm nuclei undergo a resting period
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Endosperm is the nutritive tissue for the developing embryo and the seedlings. In angiosperm, the endosperm develops from triploid primary endosperm nucleus which is formed as a result of vegetative fertilization, triple fusion or fusion of male gamete with the secondary nucleus of the central cell. Generally, endosperm divides before zygote because it will provide nourishment to the developing zygote.

So, the correct option is 'The primary endosperm nucleus divides earlier than the zygote'

Multiple choice biology reproduction in living organisms growth and development in plants sexual reproduction in plants post fertilization - plants

In angiosperms, triple fusion is required for formation of

  1. Embryo

  2. Endosperm

  3. Suspensor

  4. Fruit wall
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Angiosperms have a unique phenomenon of double fertilisation in which after the release of two male gametes inside the embryo sac by the pollen tube, one male gamete (first male gamete which is closest to the egg) fuses with egg nucleus and this phenomenon is known as fertilisation or syngamy and results in the formation of zygote.
The other male gamete i.e. the second male gamete migrates towards the secondary nucleus (formed from fusion of two polar nuclei) and fuses with it. This phenomenon is known as triple fusion and results in the formation of a triploid primary endosperm mother cell. Primary endosperm mother cell then undergoes further divisions to form endosperm. Hence, triple fusion is required for the formation of endosperm.
So, the correct answer is B.
Multiple choice biology reproduction in higher plants growth and development in plants sexual reproduction in plants post fertilization - plants

To form 100 angiosperm seeds, how many mitosis are required?

  1. 300

  2. 200

  3. 500

  4. Can't say
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

For the formation of male gametophyte, 1 meiosis and 2 mitoses are required.

and for the formation of female gametophyte 1 meiosis and 3 mitoses are required. 
One angiosperm seed contains 1 male gametophyte and 1 female gametophyte.
So, to produced 1 angiosperm seed 2+3=5 mitosis will be required.
Thus, to produce 100 angiosperm seeds, 100X5=500 mitosis will be required
S.o the correct option is '500'.

Multiple choice biology reproduction in higher plants growth and development in plants sexual reproduction in plants post fertilization - plants

Identify the wrong statements regarding post fertilization development.

  1. The ovary wall develops into pericarp.

  2. The outer integument of the ovule develops into tegmen.

  3. The fusion nucleus (triple nucleus) develops into endosperm.

  4. The ovule develops into seed.

  5. The ovary develops into fruit.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

After fertilization, the ovule matures into seeds and ovary into fruits. The process of fertilization is unique in angiosperms because it involves syngamy between male and female gametes and triple fusion between a male gamete and a secondary nucleus. Because two fertilization events are involved, it is called as double fertilization. The second fertilization is a fusion between three haploid nucleus (two forming a diploid secondary nucleus and one haploid male nucleus). Hence the secondary fertilization event is called as Triple fusion. It gives rise to a triploid primary endosperm nucleus (PEN). PEN later on gives rise to triploid endosperm. The seed coat forms from the two integuments or outer layers of cells of the ovule, which derive from tissue from the mother plant, the inner integument forms the tegmen and the outer forms the testa. The seed coats of some monocotyledon plants, such as the grasses, are not distinct structures, but are fused with the fruit wall to form a pericarp.

Multiple choice biology reproduction in higher plants growth and development in plants sexual reproduction in plants post fertilization - plants

The inner integument in majority of seeds is represented by 

  1. Hypocotyl

  2. Scutellum

  3. Tegmen

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

The outer thick layer is called as testa and inner thin one as tegmen. The seed develops from the tissue, that is the integument which originally surrounds the ovule. The seed coat forms from the two integuments or outer layers of cells of the ovule, which derive from tissue from the mother plant, the inner integument forms the tegmen and the outer forms the testa. The seed coats of some mononocotyledon plants, such as the grasses, are not distinct structures, but are fused with the fruit wall to form a pericarp.
Therefore, the correct answer is option C.