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

The polar transport of auxin in stem segments in Volvos the movement of auxin from the.

  1. Morphological apex towards the base

  2. Base towards the morphological apex

  3. Morphological apex towards the lateral

  4. Base towards the lateral branches
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Auxin exhibits polar transport in plants - moving from morphological apex toward base. This is a unique, directional transport mediated by PIN proteins and auxin influx carriers. The phrase 'in Volvos' appears to be a typo (should be 'i.e.' or 'in vivo'). Option A correctly describes the basipetal (apex to base) polar auxin transport pattern in stems.

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

Desmodium gyrans shows

  1. Autonomic movements of variation

  2. Autonomic movements of growth

  3. Paratonic movements of variation

  4. Paratonic movements of growth
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Autonomic movement is the spontaneous movement of the protoplasm due to internal stimulus. Autonomic movement of variation takes place due to changes in the turgidity of cells. The leaves of Desmodium gyrans shows jerky lateral movement due to turgor change which results in the alteration of osmotic content. A movement shown by a plant part in response to an external factor is called as paratonic movement. 

Thus, the correct answer is option A.

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

Some flowers (e.g., Oxalis) open in the morning and close during evening because of

  1. Photonasty

  2. Phototropism

  3. Phototaxis

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

Nastic movements are responses of plant parts to stimuli. Photonastic movement is the nastic response of plant in response to light. Oxalis flowers open in the morning and close during evening because of photonasty. Phototropism is the growth of a plant part in response to light. Phototaxis is the movement of a plant part in response to light. Nyctinasty is the rhythmic nastic movement of plant in response to the onset of darkness. 

Thus, the correct answer is 'Photonasty'

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

Which of the following pair is proper for plant movement?

  1. Thermotaxis - Chlamydomonas

  2. Thigmotaxis - Zoospore in Oedogonium

  3. Rotation movement - Cytoplasm in Tradeschantia anther

  4. Chemotaxis - Zoospore of Volvox
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Movement of plant in response to heat is called as thermotaxis. Movement of plant in response to a touch stimulus is called as thigmotaxis. Example include zoospore in Oedogonium. Movement of plant in response to external chemical is called as chemotaxis. Movement of plant in response to light is called as phototaxis. Chlamydomonas shows phototactic movement. 

Thus, the correct answer is 'Thigmotaxis - Zoospore in Oedogonium.'

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

Opening of floral buds is

  1. Autonomic movement of variation

  2. Paratonic movement of growth

  3. Autonomic movement of growth

  4. Autonomic movement of locomotion
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Opening of floral buds into flower is a type autonomic movement of growth. It is a nastic movement. Nastic movement is a non-directional movement shown by plant part in response to external stimuli. Greater growth on one side results in the bending on the opposite side. 
Thus, the correct answer is option C.
Multiple choice zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

During rainy seasons, the ground becomes slippery due to dense growth of

  1. Lichens

  2. Bacteria

  3. Green algae

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

Blue green algae or cyanobacteria synthesize a gelatinous mass around themselves, enclosing multiple filaments. This causes the surface area on which they thrive to be slippery

So, the correct answer is 'cyanobacteria'

Multiple choice botany pollination, fertilization and development of endosperm and embryo agents of pollination environmental conservation and biodiversity pollination and fertilization

Which of the following is a characteristics for ornithophily?

  1. Scented flowers

  2. Bright red coloured flowers and inflorescence

  3. White coloured funnel shaped large corolla

  4. Yellow flower with nectaries at the base of the corolla tube
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Ornithophily is pollination by birds, characteristic is presence of colored flowers ( mostly red) with nectaries. The orientation of the stigma and anthers is to facilitate pollen transfer for cross pollination. 
So, the correct answer is 'Yellow flower with nectaries at the base of the corolla tube'
Multiple choice biology pollination and fertilization agents of pollination environmental conservation and biodiversity pollination, fertilization and development of endosperm and embryo

Pollen grains have spiny exine to aid in

  1. Entomophily

  2. Anemophily

  3. Ornithophily

  4. Cheiropterophily
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
• Entomophily is the pollination of flowers by means of insects.
• Anemophily is the pollination of flowers by means of wind.
• Ornithophily is the pollination of flowers by means of birds.
• Chiropterophily is the pollination of flowers by means of bats.
The pollen grains which have spiny exine are related to Entomophily i.e. pollination by insects. Spines help in the attachment of the pollen to the body of pollinators. This, pollen grains have spiny exine to aid in Entomophily.
So, the correct answer is A.
Multiple choice biology pollination and fertilization agents of pollination environmental conservation and biodiversity pollination, fertilization and development of endosperm and embryo
Hydrophily occurs in

  1. Nymphaea

  2. Nelumbo

  3. Eichhornia crassipes

  4. Vallisneria/ Zostera
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Hydrophily is pollination of flowers by means of water. Example Zostera. 
When pollination occurs by water in the plants floating on the surface of the water, it is called Ephydrophily. Example Vallisneria.
In Zostera, long needle-shaped pollens are produced which float in the water. The female flower produces long structure from the stylar stigmatic region which extends to the water surface and coils around the pollen grain and pulls it underwater and thus, pollination occurs.
In Vallisneria, the male flowers detach on maturity and float on the surface of the water while the female flowers grow under water and they come up to the surface with the help of their thin long stalk. As the stalk grows further, the flowers which were vertical become horizontal and thus, a cup-like depression is formed around the female flower. The male flowers which are floating on the surface of the water, fall into the cup and due to jerk, the anthers dehisce and pollens are transferred to the stigma and thus, pollination occurs on the surface of the water. 
Hence, hydrophily occurs in Vallisneria and Zostera.
So, the correct answer is D.
Multiple choice biology pollination and fertilization agents of pollination environmental conservation and biodiversity pollination, fertilization and development of endosperm and embryo

Spiny or sticky pollen grains and large, attractively coloured flowers are associated with

  1. Hydrophily

  2. Entomophily

  3. Ornithophily

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

Entomophily type of pollination takes place through the agency of insects. The entomophilous flowers are brightly colored and fragrance to attract the insects. Their pollen grains are sticky or spiny to easily get attached with the body of pollinators. When the insects visit the flowers, their body gets dusted with pollen grains, and when they fly and visit other flowers, they brush against the stigma which being sticky, at once receives the pollen grains from their body. Thus, cross-pollination is achieved. 

So, the correct answer is 'Entomophily'.

Multiple choice biology pollination and fertilization agents of pollination environmental conservation and biodiversity pollination, fertilization and development of endosperm and embryo
Thread-like pollen without exine are found in

  1. Hydrophily

  2. Entomophily

  3. Anemophily

  4. Chiropterophily
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Thread like pollen are found in Hydrophily where pollination occurs by means of water. Such pollen grains sometimes lack exine and form thread-like structures called the viscin threads. These structures aid the pollen to swim in water and thus, pollination can occur when they come in contact with a female flower.
So, the correct answer is A.
Multiple choice biology pollination and fertilization agents of pollination environmental conservation and biodiversity pollination, fertilization and development of endosperm and embryo

The hydrophilous flowers, pollinated completely under water, are known 

as ...............

  1. Epihydrogamous

  2. Hypohydrogamous

  3. Both (A) and (B)

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

Hypohydrogamy includes the plants which are pollinated inside the water, e.g., Ceratophyllum, Naja, etc. Epihydrogamous - includes the plants which are pollinated on the surface of water.

Multiple choice biology pollination and fertilization agents of pollination environmental conservation and biodiversity pollination, fertilization and development of endosperm and embryo

Hydrophily is best demonstrated by

  1. Nelumbium

  2. Vallisneria

  3. Nymphaea

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

  • Hydrophily is the pollination by means of water. In Vallisneria, the male flower is detached from the plant and float on the surface of the water and is bought in the contact of the stigma of the female flower. 

So, option B is correct.

Multiple choice biology pollination and fertilization agents of pollination environmental conservation and biodiversity pollination, fertilization and development of endosperm and embryo

Lever mechanism for pollination is characteristic feature of

  1. Ficus

  2. Salvia

  3. Ocimum

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

Pollination mechanism in Salvia is a unique lever type. The flowers in this genus are arranged in thyrsus inflorescence and they are attractive and well adapted for cross-pollination through the agency of insects. In this lever mechanism of pollination, the Corolla has a spreading upper lip, which acts as a landing place for the insect. When the insects land on the lower lip of the corolla and in its endeavour to obtain nectar that is secreted by the hypogynous disc, pushes the sterile lobes of the stamen inwards. Due to this the upper half of the connective with the fertile lobes act as a lever. Then the anther lobe comes down and shed the pollen on the back of the insect.

Multiple choice biology pollination and fertilization agents of pollination environmental conservation and biodiversity pollination, fertilization and development of endosperm and embryo

Lever mechanism for pollination is characteristic feature of 

  1. Ficus

  2. Salvia

  3. Ocimum

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

Lever mechanism for pollination is characteristic feature of Salvia. The flowers in this genus are arranged in thysrus inflorescence and they are attractive and well adapted for cross pollination through the agency of insects. In this mechanism of pollination, the corolla has a spreading upper lip, which acts as a landing place for the insect. When the insects land on the lower lip of the corolla and in its endeavour to obtain nectar that is secreted by the hypogynous disc, pushes the sterile lobes of the stamen inwards. Due to this the upper half of the connective with the fertile lobes act as a lever. Then the anther lobe comes down and shed the pollen on the back of the insect.

So, the correct answer is option B.