Tag: plant growth

Questions Related to plant growth

 Column-1   Column-2
P) Opening of the leaf blade i) Epinasty
Q) Closing of leaves ii)hyponasty
R) zigzag movement in the apical bud iii) nutation
S) spiral and helical growth of tendrilar plants iv)circumnutation
T) pulsation in leaflets of Indian telegraph plant v) variation
development of plants plant growth growth and development plant growth and development biology

  1. (P-i) (Q-ii) (R-iii) (S-iv) (T-v)

  2. (P-v) (Q-iv) (R-iii) (S-ii) (T-i)

  3. (P-v) (Q-i) (R-iv) (S-iii) (T-ii)

  4. (P-v) (Q-i) (R-iv) (S-II) (T-iii)

Show answer
Correct Option: C
Explanation:
 Column 1  Column 2
 P) Opening of the leaf blade   variation
 Q) Closing of leaves  epinasty 
 R) Zigzag movement in the apical bud  circumnutation
 S) Spiral and helical growth of tender plants.  nutation
 T) Pulsation in leaflets of Indian telegraph plant  hyponasty

If a short day plant is given ten hours light and fourteen hour darkness but the dark period is interrupted in the middle by a flash of $730 nm$ wavelength of light, then

development of plants plant growth growth and development plant growth and development biology

  1. The floral axis becomes inactive

  2. The plant produces flowers

  3. Production of flowers is delayed, the process is suspended for that period of time

  4. The plant will produce parthenocarpic fruits

Show answer
Correct Option: C
Explanation:
If for a short day plant the period of long night is interrupted by a flash of  730nm, absorbed by $P _{fr}$ which gets converted to $P _r$ an inactive form of phytochrome, flowering does not occur
So, the correct answer is 'Production of flowers is delayed, the process is suspended for that period of time'

The pigment which mainly absorbs red and far-red radiation in plants, is known as

development of plants plant growth growth and development plant growth and development biology

  1. Cytochrome

  2. Xanthophyll

  3. Phytochrome

  4. Carotene

Show answer
Correct Option: C
Explanation:

Phytochrome is blue colored pigment present in the plants. It is a photoreceptor chromoprotein. It is mainly found in flowering plants. These are responsible for flowering. It mainly absorbs red and far-red radiation in plants and induces flowering process.

Thus, the correct answer is option C.

Phytochrome is associated with

development of plants plant growth growth and development plant growth and development biology

  1. ${P} _{r}$ and ${P} _{fr}$ reactions

  2. Absorption of red light of $660 nm$

  3. Absorption of far-red light of $740 nm$

  4. Absorption of blue-light by leaves

Show answer
Correct Option: A
Explanation:

Phytochromes are photoreceptor found in plants that detects light. The different phytochromes are involved in different biological responses to red light. P$ _r$ is inactive form whereas P$ _{fr}$ is active form of phytochrome. When exposed to red light,  P$ _r$ is converted to P$ _{fr}$. This active form then initiate many biological processes in plants.

Thus, the correct answer is 'Option A'.

State whether the following statements are true or false.
In addition to regulating flowering in some plants, phytochrome also promotes seed germination and can inhibit stem elongation.

development of plants plant growth growth and development plant growth and development biology

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Phytochromes are the hormones that are light dependent and are bluish green pigments that are involved in the developmental processes. They are light dependent and activates the inactivated form of phytochrome. They sometimes are useful in seed germination and cell elongation but stops the elongation of the stem when getting too exposed to far-red light and get inactivated.

So, the correct statement is 'True'.

Mature differentiated cells revert to meristematic activity to form callus by

development of plants plant growth growth and development plant growth and development biology

  1. Differentiation

  2. Cytodifferentiation

  3. Redifferentiation

  4. Dedifferentiation

Show answer
Correct Option: D
Explanation:

In callus culture, cell division in explant (differentiated mass of mature cells) forms and callus. Callus is an irregular unorganized and undifferentiated mass of actively dividing cells. The process is called dedifferentiation.

So the correct option is 'Dedifferentiation'.

The cells derived from meristems differentiate and regain the capacity to divide by a phenomenon called

development of plants plant growth growth and development plant growth and development biology

  1. Differentiation

  2. Dedifferentiation

  3. Redifferentiation

  4. Totipotency

  5. Regeneration

Show answer
Correct Option: B
Explanation:

In plants, apical meristems divide and differentiate to perform a specific function. This phenomenon is called as differentiation. Sometimes, the differentiated cells in plants regain the capacity to divide under certain conditions. This phenomenon is called as dedifferentiation. An interfascicular vascular cambium is an example of dedifferentiation. During dedifferentiation, certain cells lose the capacity to divide and becomes mature. This phenomenon is called as redifferentiation.

Thus, the correct answer is option B.

Which of the following is not a growth effecting factor for plants?

development of plants plant growth growth and development plant growth and development biology

  1. Water

  2. Optimum pressure

  3. Optimum light

  4. Optimum temperature

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Correct Option: B
Explanation:

Plants require four factors for its growth like:-

  • An adequate amount of water.
  • Some plants need cold condition, some moderate other hot so the temperature.
  • The adequate amount of light is needed for photosynthesis. 
  • Good amount of nutrients.

So the correct option is 'Optimum pressure'.

Which of the following is not an extrinsic factor affecting plant growth?

development of plants plant growth growth and development plant growth and development biology

  1. Light

  2. Temperature

  3. Water

  4. Phyto hormones

Show answer
Correct Option: D
Explanation:

  1. Extrinsic factors are those factors like light, water, temperature, availability of gases is the abiotic or environmental factors that control the growth of a plant. These are not controlled by the plant.
  2. Intrinsic factors like growth regulators are released by the plant and are in direct control under the plant. They regulate process like cell differentiation, cell division etc.
So, the correct option is 'Phytohormones'.

The ability of the components of cells of callus to form a whole plant is known as

development of plants plant growth growth and development plant growth and development biology

  1. Redifferentiation

  2. Dedifferentiation

  3. Both A and B

  4. None of the above

Show answer
Correct Option: B
Explanation:

The phonomenon of generation of whole plant by single cell is totipotency.It is the characteristic of plants mostly. When a plant of defferentiated tissue is cultured in a nutrient medium. Cells that are not dividing or are at resting stage undergo some changes and attain dividibility and become meristematic again. The process of reversion or regaining of meristematic activity to form callus is known as dedifferentiation while redefferentiation is the process in which the cell gains its specialization again.

So the correct option is "Dedifferentiation",