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 movement in plants living world of plants - plant physiology biology

Opening of flower bud is

  1. Curvature movement

  2. Epinasty

  3. Hyponasty

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

Plants do not move and have been evolved for stationary mode of life. However plants show several types of movements. For example, opening of a flower bud is an example of increased growth of the upper surface of a plant part (such as a leaf- vegetative or reproductive/ floral), resulting in a downward bending of the part. This type of movement is called epinasty.

Multiple choice movement in plants living world of plants - plant physiology biology

Greater growth on the lower surface of a bifacial leaf is

  1. Nyctinasty

  2. Photonasty

  3. Hyponasty

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

Plants do not move and have been evolved for stationary mode of life. However, plants show several types of movements. 

For example-the upward bending of a leaf or other plant part, resulting from greater growth of the lower side than of the upper side is called as hyponasty. It generally results in upward bending of a leaf or plant part. 
Opening of a flower bud is another example. Here increased growth of the upper surface of a plant part (such as a leaf- vegetative or reproductive/ floral), results in a downward bending of the part. This type of movement is called as epinasty.

Multiple choice movement in plants living world of plants - plant physiology biology

Opening of flower is an example of 

  1. Spontaneous movement

  2. Hyponastic movement

  3. Epinastic movement

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

Nastic movements are generally observed in leaves, flowers, petals and bud scales. In these structures at some stage of development, growth in one surface is more than the growth on the other surface. There may be two types of such movements: epinasty and hyponasty. If the upper or inner surface has more growth, the movement is called as epinasty. An example for epinasty is the opening up of a flower and the drooping of a bud. In hyponasty, there will be more growth on the lower surface.

Thus, the correct answer is option C.

Multiple choice movement in plants living world of plants - plant physiology biology

Bending of growing shoot towards sunlight is called as

  1. Heliotropism

  2. Hydrotropism

  3. Photonasty

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

Heliotropism, a form of tropism, is the diurnal motion or seasonal motion of plant parts (flowers or leaves) in response to the direction of the sun. The habit of some plants to move in the direction of the sun was already known by the Ancient Greeks.

Hydrotropism  is a plant's growth response in which the direction of growth is determined by a stimulus or gradient in water concentration.
Photonasty -  A nastic response of a plant organ to the stimulus of light. 
Thigmotropism is a movement in which a plant moves or grows in response to touch or contact stimuli. 
Therefore, the correct answer is option A.

Multiple choice movement in plants living world of plants - plant physiology biology

Tertiary roots are

  1. Positively geotropic

  2. Negatively geotropic

  3. Plagiogeotropic

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

The branches of the secondary roots are called tertiary roots. Some of the lateral organs possess little or no geotropic sensitivty. It is thus termed as ageotropic. Example of such a plant: corolloid root of cycas.

Multiple choice movement in plants living world of plants - plant physiology biology

Jerky lateral leaflet movements of Desmodium gyrans are

  1. Negative geotropic movements

  2. Positive geotropic movements

  3. Hydrotropic movements

  4. None of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Desmodium gyrans is well known as the 'telegraph plant' and famous for its movement. The small lateral leaflets will rotate on their axis, moving in jerky motions under the slightest influence of touch, sunshine, warmth or small vibrations. At night they droop downwards
So, the correct answer is 'None of the above'
Multiple choice movement in plants living world of plants - plant physiology biology

Grasses fold their leaves due to 

  1. Bulliform cells

  2. Stomata

  3. Hydathodes

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

Bulliform cells are large, bubble-shaped epidermal cells present in the leaves of many grasses that lose water and cause the leaves to fold or roll during drought.

Multiple choice movement in plants living world of plants - plant physiology biology

Which type of trophism is shown by tulip and sunflower respectively?

  1. Thigmonasty and photonasty

  2. Hydronasty and thermonasty

  3. Thermonasty and photonasty

  4. Hydronasty and photonasty
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The flowers of sunflower open in the morning which is an example of photonasty (regulated by light). Tulip flowers open at high temperature, example of thermonasty (regulated by temperature).

Multiple choice movement in plants living world of plants - plant physiology biology

Opening of flowers involves

  1. Epinasty

  2. Hyponasty

  3. Nutation

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

Nastic movements are responses of plant parts to stimuli. Epinasty is the downward bending of a leaf resulting from greater growth of the upper side than of the lower side. Due to more growth on the upper side, the flower will open due to epinasty. The hyponasty is an upward bending of leaves resulting from greater growth of the lower side. Nutation is the bending movements shown by some plant parts due to the unequal rate of growth of different parts of plants. Movement of plant in response to light is called as phototaxis.

Thus, the correct answer is option A.

Multiple choice movement in plants living world of plants - plant physiology biology

What is the type of movement that occurs during opening and closing of flowers?

  1. Nastic movement

  2. Tactic movement

  3. Tropic movement

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

Nastic movements are responses of plant parts to stimuli. Epinasty is the downward bending of a leaf resulting from greater growth of the upper side than of the lower side. Due to more growth on the upper side, the flower will open. The hyponasty is an upward bending or uncoiling of leaves resulting from greater growth of the lower side. Due to more growth on the lower side, the flower will close. Tactic movements are response of plant parts to external stimuli like light, chemicals. Tropic movements are response of plant parts to external stimuli like gravity, light, touch. Nutation is the bending movements shown by some plant parts due to the unequal rate of growth of different parts of plants. 

Thus, the correct answer is option A.

Multiple choice movement in plants living world of plants - plant physiology biology

Circinate ptyxis present in fern leaves is due to

  1. Epinasty

  2. Hyponasty

  3. Nutation

  4. Movement of variation
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Nastic movements are responses of plant parts to stimuli. Epinasty is the downward bending of a leaf resulting from greater growth of the upper side than of the lower side. Due to more growth on the upper side, the flower will open as a result of epinasty. The hyponasty is an upward bending or uncoiling of leaves resulting from greater growth of the lower side. Circinate ptyxis is found only in fern leaves due to hypoasty. Nutation is the bending movements shown by some plant parts due to the unequal rate of growth of different parts of plants. 

Thus, the correct answer is option B.

Multiple choice movement in plants living world of plants - plant physiology biology

Opening of flower and drooping of a bud are 

  1. Hyponasty

  2. Epinasty

  3. Curvature movement

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

Nastic movements are responses of plant parts to stimuli. Epinasty is the downward bending or drooping of a bud resulting from greater growth of the upper side than of the lower side. Due to more growth on the upper side, the flower will open as a result of epinasty. The hyponasty is an upward bending or uncoiling of leaves resulting from greater growth of the lower side. 

Thus, the correct answer is option B.

Multiple choice movement in plants living world of plants - plant physiology biology

In hyponasty, the bud will remain

  1. Open

  2. Closed

  3. Semi-open

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

Nastic movements are responses to plant parts to stimuli. Epinasty is the downward bending or drooping of a bud resulting from the greater growth of the upper side than of the lower side. Due to more growth on the upper side, the flower will open as a result of epinasty. The hyponasty is an upward bending or uncoiling of leaves resulting from the greater growth of the lower side. Due to more growth on the lower side, the flower will remain closed as a result of hyponasty.

Thus, the correct answer is option B.

Multiple choice movement in plants living world of plants - plant physiology biology

Which type of movement is shown by Tulip and Sunflower respectively?

  1. Thermonasty and photonasty

  2. Hydronasty and photonasty

  3. Thigmonasty and photonasty

  4. Hydronasty and thermonasty
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Nastic movements are responses to plant parts to stimuli. Thermonasty is nastic movement shown by the plant in response to high temperature. Photonasty is nastic movement shown by the plant in response to light. Hydronasty is nastic movement shown by the plant in response to water current. Thigmonasty is nastic movement shown by the plant in response to touch or vibration. Opening and closing of tulip flower is thermonastic movement. Sunflower shows photonastic movement. Thus, the correct answer is option A.

Multiple choice movement in plants living world of plants - plant physiology biology

Which flower shows nyctinastic movement?

  1. Albizzia lebbek

  2. Pentapetes

  3. Mimosa pudica

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

Nyctinastic movement is the rhythmic nastic movement of plant in response to the onset of darkness. It is also called as sleep movement. Drooping of legume leaves in dark is due to nyctinasty. Mimosa pudica shows nyctinastic movement. 

Thus, the correct answer is option C.