What do the following transport?
(i)Xylem (ii) phloem (iii) pulmonary artery (iv) pulmonary vein
Answers
1)XYLEM:
The xylem is responsible for keeping a plant hydrated. Xylem sap travels upwards and has to overcome serious gravitational forces to deliver water to a plant’s upper extremities, especially in tall trees.
Two different types of cells are known to form the xylem in different plant groups: tracheids and vessel elements. Tracheids are found in most gymnosperms, ferns, and lycophytes whereas vessel elements form the xylem of almost all angiosperms.
Xylem cells are dead, elongated and hollow. They have secondary cell walls and ‘pits’ (areas where the secondary cell wall is missing).
2)PHLOEM:
The phloem carries important sugars, organic compounds, and minerals around a plant. Sap within the phloem simply travels by diffusion between cells and works its way from leaves down to the roots with help from gravity. The phloem is made from cells called ‘sieve-tube members’ and ‘companion cells’.
3) pulmonary artery:
pulmonary artery carries deoxygenated blood from the right ventricle to the lungs. the blood hair passes through capillaries adjacent to alveoliand becomes oxygenated as part of the process of respiration.
4) pulmonary vein:
pulmonary veins are responsible for carrying oxygenated blood from the lungs back to the left atrium of the heart. this differentiates the pulmonary vein from other veins in body. which which are used to carry e oxygenated blood from the rest of the body back to the heart. these carry blood from the right lung.