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 pollination and fertilization types of pollination cross pollination pollination and its types

Faster and better growth of pollen from other plants than the pollen from the same plant is?

  1. Self incompatibility

  2. Dichogamy

  3. Monocliny

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

Self-incompatibility is the widespread mechanism in flowering plants which prevents the inbreeding and promotes the outcrossing. Dichogamy is the mechanism when the stigma and anther mature at different times.  Monocliny i.e. Bisexuality is applicable for bisexual flowers. Pollen prepotency is the mechanism when the pollen of a different flower germinates faster than of the same flower thus preventing autogamy.

Thus, the correct option is D.

Multiple choice botany pollination and fertilization types of pollination cross pollination pollination and its types

Barrier to avoid self pollination between stamens and pistils is

  1. Heterostyly

  2. Herkogamy

  3. Dichogamy

  4. Dicliny
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Plants have adapted various ways to prevent self pollination, such as:
Heterostyly- It is the occurrence of 2-3 types of flowers within the same plant and such flowers have the difference in length of styles and stamens.
Herkogamy- It is the condition in which the flower structure is such that even being bisexual, the pollen grains fail to reach the stigma. In some flowers, a mechanical barrier exists between the compatible pollen and stigma so that self pollination is not possible. Sometimes, there is a hood like covering that covers the stigma.
Dichogamy- It is the condition when the anther and stigma mature at different times. Either anthers dehisce before the stigma becomes receptive (called protandry) or stigma becomes receptive before anthers dehisce (called protogyny).
Dicliny- It is the presence of only one kind of reproductive whorl in a flower. It is also called unisexuality.
Therefore, from all of the above measures, herkogamy is the one in which self pollination is prevented by floral barriers between stamens and pistils.
So, the correct answer is B.
Multiple choice botany pollination and fertilization types of pollination cross pollination pollination and its types

Nontransfer of pollen from anther to stigma of the same flower due to a mechanical barrier is

  1. Dichogamy

  2. Herkogamy

  3. Heterostyly

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

Dichogamy- It is the condition when the anther and stigma mature at different times. Either anthers dehisce before the stigma becomes receptive (called protandry) or stigma becomes receptive before anthers dehisce (called protogyny).

Herkogamy- It is the condition in which the flower structure is such that even being bisexual, the pollen grains fail to reach the stigma. In some flowers, a mechanical barrier exists between the compatible pollen and stigma so that self pollination is not possible. Sometimes, there is a hood like covering that covers the stigma.
Heterostyly- It is the occurrence of 2-3 types of flowers within the same plant and such flowers have the difference in length of styles and stamens.
Cleistogamy- It is a phenomenon, where flowers never open and in such flowers, only self-pollination occurs within the bud (unopened flower). In such flowers, anthers and stigma lie close to each other. When the anthers dehisce in the flower buds, pollen grains come in contact with the stigma and pollination occurs. 
Thus, from all the options given in question, mechanical barrier to prevent the transfer of pollen grains from the anther to the stigma is found in Herkogamy.
So, the correct answer is B.

Multiple choice botany pollination and fertilization types of pollination cross pollination pollination and its types

Which is not a correct explanation of cross pollination?

  1. Pollen grains of male flowers are transferred to stigma of female flowers

  2. Pollen grains are transferred from one flower to another flower of another plant of the same species

  3. Pollen grains are transferred from one flower to another flower situated on the same species

  4. Pollen grains of one flower are transferred to the stigma of the same flower
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Cross-pollination involves the transfer of pollen from one flower to another. Transferring pollen to the same flower is self-pollination, not cross-pollination.

Multiple choice botany pollination and fertilization types of pollination cross pollination pollination and its types
Gloriosa superba exhibits

  1. Heterostyly

  2. Self sterility

  3. Herkogamy

  4. Cleistogamy
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
In Gloriosa superba, flower structure is such that inspite of being bisexual the pollen grains are not able to reach the stigma. The anther dehisce outwardly at a distance from the stigma and therefore, pollen can't fall on the stigma and self-pollination is prevented. This adaptation by Gloriosa to prevent self-pollination by means of floral barriers is called Herkogamy.
So, the correct answer is C.
Multiple choice botany pollination and fertilization types of pollination cross pollination pollination and its types

The maturation of anthers and stigmas at times in the same flower is known as _____________.

  1. Herkogamy

  2. Cleistogamy

  3. Chasmogamy

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

Dichogamy is the maturation of anthers (male organs) and stigmas (female organs) at different times in the same flower to prevent self-pollination. Herkogamy involves spatial separation, and cleistogamy involves flowers that do not open.

Multiple choice botany pollination and fertilization types of pollination cross pollination pollination and its types

Maturation of stigma and anthers at different times in the same flower is

  1. Heterostyly

  2. Dichogamy

  3. Dicliny

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

Heterostyly- It is the occurrence of 2-3 types of flowers within the same plant and such flowers have the difference in length of styles and stamens.

Dichogamy- It is the condition when the anther and stigma mature at different times. Either anthers dehisce before the stigma becomes receptive (called protandry) or stigma becomes receptive before anthers dehisce (called protogyny).
Dicliny- It is the presence of only one kind of reproductive whorl in a flower. It is also called unisexuality.
Herkogamy- It is the condition in which the flower structure is such that even being bisexual, the pollen grains fail to reach the stigma. In some flowers, a mechanical barrier exists between the compatible pollen and stigma so that self pollination is not possible. Sometimes, there is a hood like covering that covers the stigma.
So, the correct answer is B.

Multiple choice botany pollination and fertilization types of pollination cross pollination pollination and its types

Dichogamy is

  1. Placement of anthers and stigmas at different levels

  2. Inability of the pollen to germinate on the stigma of the same flower

  3. Occurrence of barrier between anther and stigma of the same flower

  4. Maturation of anthers and stigmas at different times
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Dichogamy- It is the condition when the anther and stigma mature at different times. Either anthers dehisce before the stigma becomes receptive (called protandry) or stigma becomes receptive before anthers dehisce (called protogyny).

While placement of anthers and stigma at different levels is called Heterostyly, inability of pollen to germinate on the stigma of the flower is called self-incompatibility and the occurrence of a barrier between anther and stigma of the same flower is called Herkogamy.
So, the correct answer is D.

Multiple choice botany pollination and fertilization types of pollination cross pollination pollination and its types

The features where stamens and stigma mature at different times favouring cross pollination is known as?

  1. Dichogamy

  2. Herkogamy

  3. Autogamy

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

Herkogamy is shown by hermaphroditic angiosperms to reduce sexual interference between anthers and female stigma function. Autogamy, or self-fertilization, refers to the fusion of two gametes that come from one individual. cleistogamy is self-fertilization that occurs within a permanently closed flower. Dichogamy means when stamens and stigma mature at different times favouring cross-pollination. 


So, 'the correct option is 'Dichogamy'

Multiple choice botany pollination and fertilization types of pollination cross pollination pollination and its types

Cross-pollination is favoured by

  1. Self-sterility

  2. Dichogamy

  3. Herkogamy and heterostyly

  4. All of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Cross-pollination is when one plant pollinates a plant of another variety. The two plants' genetic material combines and the resulting seeds from that pollination will have characteristics of both varieties and is a new variety. Self-sterility in plants is enhanced to prevent self-fertilization and increase family diversification. Dichogamy is the ripening of the stamens and pistils of a flower at different times so that self-fertilization is prevented. Herkogamy is a common strategy employed by hermaphroditic angiosperms to reduce sexual interference between male (anthers) and female (stigma) function. Heterostyly is a unique form of polymorphism and herkogamy in flowers. In a heterostylous species, two or three morphological types of flowers, exist in the population. All these prevent self-pollination and favour cross-pollination.

So, the correct option is, 'all of these'.

Multiple choice botany pollination and fertilization types of pollination cross pollination pollination and its types

The phenomenon of maturation of anthers earlier than the stigma of the same flower is

  1. Dicliny

  2. Protandry

  3. Herkogamy

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

Heterostyly is the occurrence of 2-3 types of flowers within the same plant. Such flowers have a difference in length of styles and stamens.

Protandry is the condition when anthers mature before the stigma becomes receptive is called protandry. So, the condition in which the male reproductive organs of a flower mature before the female ones, and hence ensuring that self-fertilization does not occur.

Dicliny is the presence of only one kind of reproductive whorl in a flower.

Herkogamy is the condition in which the flower structure is such that even being bisexual. In some flowers, a mechanical barrier exists and thus self-pollination is not possible. Sometimes, there is a hood for covering the stigma.

So, the correct answer is B.

Multiple choice chemistry nitrogen and sulfur sulfur and its oxides acid deposition natural resources- air, water and land

The loss or reduction of chlorophyll in the leaves is termed as:

  1. necrosis

  2. chlorosis

  3. epinasty

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

Necrosis is the death of body tissue. It occurs when there is some infection or the supply to the part of the plant has stopped. This can also occur from injury, radiation or chemicals.
Chlorosis is yellowing of leaf tissue due to lack of chlorophyll. Possible causes of chlorosis include poor drainage, damaged roots, and compacted roots.
Epinasty is increased growth on the upper surface of an organ or part, causing it to bend downward.
Lichens are made up of two or more closely interacting organisms, a fungus and one or more partners called photobionts. 
Thus, the correct answer is option B. 

Multiple choice botany families of angiosperms family fabaceae eudicots family - fabaceae, sativum and solanaceae study of some important families

One of the following is the typical floral formula of Brassicaceae (Cruciferae).

  1. $K _{2+2}C _4A _{2+4}\underline{G} _{(2)}$
  2. $K _4C _{2+2}A _{3+3}\overline{G} _{(2)}$
  3. $K _{2+2}C _{2+2}A _6\underline{G} _{(1)}$
  4. $K _4C _4A _6\underline{G} _{(2)}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Brassicaceae family has flower with 4 sepals in two whorls with imbricate aestivation, 4 petals in valvate aestivation, 6 stamens in two whorls in tetradynamous condition (4 stamens longer than other two), bicarpellary ovary with false septation showing two locules. 

Thus, the correct answer is option A.

Multiple choice botany families of angiosperms family fabaceae eudicots family - fabaceae, sativum and solanaceae study of some important families

A diagnostic feature for identification of pea (Fabaceae) flower is

  1. Tetradynamous stamens

  2. Inferior ovary

  3. Cruciform corolla

  4. Vexillary aestivation in petals
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Fabaceae is a family that was earlier called Papilionoideae and a subfamily Leguminosae. In this type of flower five petals called polypetalous, aestivation descending imbricate or vexillary. In vexillary aestivation, there are five petals. The largest petal (called standard) overlaps the two lateral petals (called wings) which further overlap the two smallest anterior petals (called keel).
So, the correct answer is 'Vexillary aestivation in petals'.