Botany and Plant Science

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.

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.

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. 

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.

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. 

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. 

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. 

The apogeotropic or positively geotropic roots appear in Cycas sporophyte are called Corolloid roots or Corollorhiza. These roots looks like anthozoans or coelenterates. They contain Blue green algae or cyanobacteria like Nostoc and Anabaena, and perform symbiotic nitrogen fixation. They show mutual association with plant body.

So, the correct option is ‘Cyanobacteria’.

Roots of the tobacco plants are infected by Meloidogyne incognita. RNA I method is used to develop resistance in these plants against infection.

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.