(a) Draw a labelled diagram of (z) a xylem vessel, and (ii) a sieve tube (or phloem).
(b) What are the differences between the transport of materials in xylem and phloem ?
The Structure of xylem vessels
The Structure of phloem (made of sieve tubes)
(i) Xylem Transports water and minerals
Phloem transports food material which the plants make
(ii) It transports material in upward direction only
It transports material in all the directions
Match the terms in column I with their uses in column II
(a) Pipes for transport in humans
(ii) Arteries and Veins
(b) Clotting of blood
(iii) Xylem vessels
(c) pumping organ
(d) Water transport in plants
(e) Carrier of Oxygen
Define excretion. Name the excretory unit of a kidney.
The process of removal of toxic waste from the body of an organism is called excretion. The excretory unit of a kidney is called nephron.
(a) What job is done by the kidneys ?
(b) What do kidneys excrete ?
(c) What is the name of the tubes which connect the kidneys to bladder ?
(d) What does the bladder in our body do ?
(a) The kidneys remove the poisonous substance urea, other waste salts and excess water from the blood in the form of yellowish liquid called urine.(b) Urea.(c) Ureters.(d) Urinary bladder is a bag which stores the urine temporarily till it is excreted out.
Why do some people need to use a dialysis machine ? What does the machine do ?
When there is a kidney failure then dialysis machine is used. Dialysis cleans the blood of a person by separating the waste substance (urea) from the blood.
What is the liquid part of the blood called ? What is the function of platelets in the blood ?
The liquid part of the blood is called plasma. Platelets help in the coagulation of blood in a cut or wound.