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 biology movement and locomotion in living organisms movements in plants coordination in plants tropic and nastic movements in plants

Geotropic response is perceived by

  1. Mature roots

  2. Elongating cells

  3. Root cap

  4. Root hairs
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Geotropic stimulus is perceived by root cap in case of root and by stem apex in case of stem. Geotropic stimulus is perceived by root cap because it is the adjacent part in touch with soil. In the case of aquatic plants, the plant has root pocket instead of root cap in terrestrial plants
So, the correct answer is 'Root cap'
Multiple choice biology movement and locomotion in living organisms movements in plants coordination in plants tropic and nastic movements in plants

The site which receives the phototropic stimulus is

  1. Shoot apex (tip)

  2. Root apex (tip)

  3. Meristematic regions

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

The area of the plant which receives a stimulus is called as perceptive region. Tip or apex of the shoot is the perceptive region for the light. It is the site which receives the phototropic stimulus and shows corresponding response. 

Thus, the correct answer is option A.

Multiple choice biology movement and locomotion in living organisms movements in plants coordination in plants tropic and nastic movements in plants

The area of photoperception is

  1. Region of elongation

  2. Tip

  3. Young leaves

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

The area of the plant which perceives a stimulus is called as perceptive region. Tip of the stem is the perceptive region for the light. The area of the plant which shows the response is called as responsive region. 

So, the correct answer is 'Tip'

Multiple choice biology movement and locomotion in living organisms movements in plants coordination in plants tropic and nastic movements in plants

The style in Arachis before fertilization is

  1. Positive phototropic

  2. Negative phototropic

  3. Positive geotropic

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

The movement of plants in response to light is referred to as phototropism and to gravity is called geotropism. Arachis hypogea or peanut or groundnut belonging to the family Fabaceae or Leguminoseae, this is a herbaceous plant with yellowish organ flowers borne on auxillary clusters with ovary positioned at the base of the floral cup. The stigma is supported on a long style and before fertilization this shows positive phototropism.

Multiple choice biology movement and locomotion in living organisms movements in plants coordination in plants tropic and nastic movements in plants

Plant shoots grow upwards and show--------

  1. Positive phototropic

  2. Negative phototropic

  3. Positive geotropic

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

A tropism can be positive or negative.
Positive: the growth response is in the direction of the stimulus.
Negative: the growth response is away from the stimulus.
Light intensity, day length, gravity and temperature are major factors that influence plant growth. Phototropism is the growth response of a plant in response to light direction. Positive phototropism and negative geotropism of stems. The stems will grow towards the light and up away from gravity.

Therefore, the correct answer is option A.

Multiple choice biology movement and locomotion in living organisms movements in plants coordination in plants tropic and nastic movements in plants

Thigmotropism is best exhibited by

  1. Tendrils

  2. Stem apex

  3. Root apex

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

Thigmotropism' also known as 'Haptotropism' term arises from; Thigm+ tropism. 'Thigm' means a touch. 'Tropism' means an orienting response of an organism to the stimulus. 'Thigmotropism' is the directional growth movement which occurs as a mechanosensory response to a touch stimulus. The response exhibited by the organism to the stimulus is mostly involuntary, which means it can go either away or towards from the stimulus of the source as in taxis. The directional response is generally caused by the induction of some pattern of differential growth. The best example is climbing tendrils of the sweet pea when feel the solid object like tree trunk, causes the tendrils to actually attain curvature with that object. Thigmotropism can be positive or negative

So, the correct answer is 'Tendrils'

Multiple choice biology movement and locomotion in living organisms movements in plants coordination in plants tropic and nastic movements in plants

Thigmotropism is best exhibited by  

  1. Tendrils

  2. Stem apex

  3. Root apex

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

Thigmotropism is the directed tropical growth movement of plant in response to touch. Tendrils are the modified leaves that grow straight until it touch the support. Contact with any support stimulates the cell to grow at different rates at opposite sides of tendrils and causes their curling around the support. Thus, option A is correct. 

Multiple choice biology movement and locomotion in living organisms movements in plants coordination in plants tropic and nastic movements in plants

Thigmotropism is best seen in the 

  1. Root apex growth

  2. Stem apex growth

  3. Tendrils coiling

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

Thigmotropism is response of plants to touch or contact with a solid object. Tendrils feel the solid object resulting in the coiling response. This type of movement helps weak stem of vines and climbers to grow. Thus the correct answer is option C.

Multiple choice biology movement and locomotion in living organisms movements in plants coordination in plants tropic and nastic movements in plants

Which among the following is an example of chemotropism?

i. Formation of tendrils
ii. Fertilization of flowers by pollen
iii. Growth of plant roots
iv. Falling of leaves

  1. (ii) and (iii)

  2. (i) and (iv)

  3. (i) and (ii)

  4. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

  • An example of chemotropic movement can be seen during the growth of the pollen tube, where growth is towards the ovules.
  •  Fertilization of flowers by pollen is achieved because the ovary releases chemicals that produce a positive chemotropic response from the developing pollen tube. 
  • An example of positive and negative chemotropism is shown by plant roots. 
  • The roots grow towards useful minerals displaying positive chemotropism and grow away from harmful acids displaying negative chemotropism. 


Therefore, the correct answer is option C.

Multiple choice biology movement and locomotion in living organisms movements in plants coordination in plants tropic and nastic movements in plants

Negative phototropism occurs in

  1. Root

  2. Stem

  3. Leaf

  4. Flower
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Phototropism is the movement or bending of plants towards light. While roots grow in a direction opposite to that of light and is thus called as negatively phototropic. At the same time, roots grow positively geotropic
So, the correct answer is 'Root'
Multiple choice biology movement and locomotion in living organisms movements in plants coordination in plants tropic and nastic movements in plants

Thigmotropism is best seen in

  1. Root apex

  2. Stem apex

  3. Leaf apex

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

Thigmotropism is the directional response of a plant part to touch with a solid object. It is best seen in tendrils. Upon contact with the stimulus, it shows curving up towards the stimulus. Tendrils grow toward the touch stimulus, and wrap around the object.

Thus, the correct answer is option D. 

Multiple choice biology movement and locomotion in living organisms movements in plants coordination in plants tropic and nastic movements in plants

Pollen tubes exhibit

  1. Haptotropism

  2. Chemotropism

  3. Anemotropism

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

The movement of parts of a plant in response to a touch stimulus is called as haptotropism. The movement of parts of a plant in response to external chemical stimulus is called as chemotropism. An example is growth of the pollen tube towards the ovules. The movement of parts of a plant in response to air current is called as anemotropism. The movement of parts of a plant in response to sunlight is called as heliotropism. 

Thus, the correct answer is option B.

Multiple choice biology movement and locomotion in living organisms movements in plants coordination in plants tropic and nastic movements in plants

Entwining of Grape Vine tendril around a support is

  1. Thigmotropism

  2. Nutation

  3. Gravitropism

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

Thigmotropism is a directional growth movement in response to a touch stimulus. It is found in twining plants and tendrils. Grape vine tendril entwines around a support due to thigmotropic movement. Nutation is the bending movement shown by plant during its development. Growth movement in response to gravity is called as gravitropism. Nastic movement in response to external stimulus is called as chemonasty. 

Thus, the correct answer is option A.

Multiple choice biology movement and locomotion in living organisms movements in plants coordination in plants tropic and nastic movements in plants

Secondary roots are generally

  1. Diageotropic

  2. Positively geotropic

  3. Ageotropic

  4. Plagio-geotropic
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Diageotropic is the part of plant that grows at a right angle to the direction of gravity. Example of diageotropic include rhizome, runner. Plagiogeotropic is the part of plant that grows at intermediate angle between $0^o$ and $90^o$ to the direction of gravity. Secondary roots are examples of plagiogeotropic. Positively geotropic is part of plant that grows in the direction of gravity. Roots are examples of positively geotropic organ.
So, the correct answer is 'Plagio-geotropic'
Multiple choice biology movement and locomotion in living organisms movements in plants coordination in plants tropic and nastic movements in plants

Thigmotropism is best exhibited by

  1. Lamina

  2. Tendrils

  3. Root apex

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

Thigmotropism is a directional growth movement in response to a touch stimulus. It is found in twining plants and tendrils. Grape vine tendril entwines around a support due to thigmotropic movement. 

Thus, the correct answer is option B.