Question

Xylem and phloem are parts of

Group of answer choices

the vascular system in plants

names for the hairs of a dandelion flower

the photosynthetic system in plants

involved directly in protein synthesis

Answer 1

xylem and phloem are the parts of vascular system in plants.

explanation --

Vascular system, in plants, is assemblage of conducting tissues and associated supportive fibres. These conducting tissues are xylem and phloem.

xylem is a complex structure of plants responsible for transport of water and other nutrient from roots to stem and leaves. It is unidirectional (stem to leaves) . These are tubular shaped with no cross wall. They occupies the centre of vascular bundle.

Phloem transport food from photosynthesising parts like leaves to non photosynthesising parts of plants like root or stem. It is bi-directional (leaves to stem or root). These are elongated, tubular with thin walled seive. They lie outside vascular bundles.

They are the vascular tissues of the plant and together form vascular bundles.

Vascular bundles run longitudinally along the stem. Vascular rays extend radially across the stem, assisting in conduction from the vascular bundles to tissues alongside them.

* For plants to perform photosynthesis they require light energy from the sun, water and carbon dioxide. Water is absorbed from the soil into the cells of roots. The water passes from the root system to the xylem vessels in the stem until it reaches the leaves. Carbon dioxide is absorbed from the atmosphere through pores in the leaves called stomata. So the photosynthesis system in plant is made up by stomata .Xylem vessels only help in water transpiration and does not form the photosynthesis systems.

* proteins are sunthesised from amino acids and these amino acids are transported to sinks via phloem in plants.in cases where amino acids are formed in root, they are transported via xylem through transpiration stream upto the leaves. This way they help in protein synthesis.