Tag: root

Rema observed trichomes which are considered to be the outgrowth from the epidermis of the plant and are unicellular and mostly glandular. It helps in the absorption of water and minerals.

A)The root is covered at the apex by a thimble-like structure called the root cap that protects it from damage.

Quiscent centre is a zone of mitotically inactive zone in the meristematic region of the root apical meristem. The cells of this region either do not divide or divide very slowly. They have thin cytoplasm, low concentration of the RNA and proteins, fewer endoplasmic reticulum and dictyosomes. This zone acts as reservoir of meristematic cells. The cells ar ecapable of gaining the active dision activity at the time of growth.

Chloroplast are absent in root hairs because root hairs do not produce food. These are meant for absorption of water and minerals from soil. Chloroplast is the store house of chlorophyll which is the green pigment essential in photosynthesis.Moreover root and root hair are underground structures away from light, hence they do not contain chloroplasts, as chlorophyll pigments present within the chloroplasts are functional only in presence of light.

Screwpine or Pandanus also known as screw palm has stilt roots. Often called as Pandanus palms, these plants are not closely related to palm trees. The species vary in size from small shrubs less than 1 m. Species growing on exposed coastal headlands and along beaches have thick stilt roots- as anchors in the loose sand. Those prop roots emerge from the stem, usually close to but above the ground, which helps to keep the plants upright and secure them to the ground.
Thus, the correct answer is option C.

Asafoetida or hing is the dried latex (gum oleoresin) exuded from the rhizome or tap root of several species of Ferula, a perennial herb that grows 1 to 1.5 m tall. The species is native to the deserts of Iran, mountains of Afghanistan and is mainly cultivated in nearby India. Thus, option A is correct. 

Velamen is a spongy, multiple epidermis that covers the roots of some epiphytic or semi-epiphytic plants, such as orchid and Clivia species. The velamen of an orchid is the white or gray covering of aerial roots when dry, and usually more green when wet as a result of the appearance of underlying photosynthetic structures. It is many cell layers thick and capable of absorbing atmospheric moisture and nutrients. Often, the roots of orchids are associated with symbiotic fungi or bacteria, the latter may fix nutrients from the air. This functionality allows the orchid to exist in locations that provide a reproductive or vegetative advantage such as improved exposure or reduced competition from other plant species. The velamen also serves a mechanical function, protecting the vascular tissues in the root cortex, shielding the root from transpirational water loss and in many cases, adhering the plant to the substrate. So, velamen tissues are associated with absorption of moisture and not with nutrition, assimilation and haustorial function.
Thus, the correct answer is option C.

In some plants, the roots are chlorophyllous and perform photosynthesis. For example, Tinospora, Taeniophyllm, Trapa, Podostemum.