Tag: botany

Questions Related to botany

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

  1. Dichogamy

  2. Herkogamy

  3. Autogamy

  4. Cleistogay


Correct Option: A
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'

Allogamy is best favoured by ...............

  1. Cleistogamy

  2. Dicliny

  3. Homogamy

  4. None above


Correct Option: B
Explanation:

In plants, allogamy is used specifically to mean the use of pollen from one plant to fertilize the flower of another plant and are usually synonymous with the term cross fertilization , though the latter can be used more specifically to mean pollen exchange between different plant strains or even different individuals. Allogamy is best favoured by Dicliny. Dicliny refers to unisexual flowers. This is of two types: monoecy and dioecy.

Outbreeding devices which is/are strcturally bisexual but functionally unisexual

  1. Dichogamy

  2. Herkogamy

  3. Dicliny

  4. Both A and B


Correct Option: A
Explanation:

Continous self-pollination or inbreeding leads to inbreeding depression, a condition where the decrease in genetic vigor and vitality results in reduced fitness in offsprings.
Dichogamy is the condition in some flowering plants where the pistils and stamens mature at different times, thus preventing self-pollination.
It is of two types: protandry and protogyny.

So, the correct answer is 'Dichogamy'.

Which of the following plants shows the self-sterility?

  1. Tobacco

  2. Potato

  3. Crucifers

  4. All of the above


Correct Option: D
Explanation:

Incapability of pollen grains of one flower to grow over the stigma of the same flower due to the presence of similar sterile genes is called self-sterility. Ex: Tobacco, Crucifers, Potato and Gramineae.

So the correct option is 'Tobacco, Potato and Crucifers'.

Self-sterility can be related to which of the following phenomena?

  1. Emasculation

  2. Sexual incompatibility

  3. Cross pollination

  4. All of the above


Correct Option: D
Explanation:

Incapability of pollen grains of one flower to grow over the stigma of the same flower due to the presence of similar sterile genes is called self-sterility. Which a leads to emasculation, sexual incompatibility, and cross-pollination.

So the correct option is 'Emasculation, Sexual incompatibility, and Cross-pollination'.

Cross-pollination is favoured by

  1. Self-sterility

  2. Dichogamy

  3. Herkogamy and heterostyly

  4. All of these


Correct Option: D
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'.

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

  1. Dicliny

  2. Protandry

  3. Herkogamy

  4. Heterostyly


Correct Option: B
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.

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. $K _4C _4A _6\underline{G} _{(2)}$


Correct Option: A
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.

Gram belongs to family

  1. Papilionaceae

  2. Asteraceae

  3. Liliaceae

  4. Solanaceae


Correct Option: A
Explanation:

Cicer arietinum, commonly known as chickpea, gram or Bengal gram is an annual legume belonging to family Fabaceae or Papilionaceae. The chickpea seeds are rich in protein. It is one of the earliest cultivated legumes and it is native to Middle East countries. It is used for human consumption and it is also used as animal fodder because it is rich in protein content. So, the correct answer is 'Papilionaceae'.

Plants which provide pulses belong to family

  1. Asteraceae

  2. Fabaceae

  3. Poaceae

  4. Solanaceae


Correct Option: B
Explanation:

Fabaceae or Leguminosae, commonly known as a legume, pea or bean family is a large and economically important family of flowering plants. It includes trees, annual or perennial herbaceous plants and shrubs. Fabaceae includes a number of agricultural and food plants such as cereals, pulses, fruits, roots etc. Hence, plants which provide pulses such as chickpea, Bengal gram etc. belong to family Fabaceae.

So, the correct answer is 'Fabaceae'.