Biology - Study Mode

[#711] Which cell division of phase of cell division maintains the chromosomes number constant from generation to generation?
Correct Answer

(B) Meiosis

Explanation

Solution: In summary, meiosis is a form of cell division that results in half the normal number of chromosomes in sex cells, or gametes, thus maintaining the chromosome number of a species from generation to generation.

[#712] Mitosis cannot take place bacteria because they lack ________
Correct Answer

(B) Nucleus

Explanation

Solution: There are many differences between prokaryotic and eukaryotic cell division. Bacteria have a single, circular DNA chromosome and no nucleus. Therefore, mitosis is not necessary in bacterial cell division.

[#713] Red colour of blood is due to presence of
Correct Answer

(B) Hemoglobin

Explanation

Solution: Red colour of blood is due to presence of Hemoglobin.

[#714] Average life span of human R.B.C is
Correct Answer

(C) 120 days

Explanation

Solution: Average life span of human R.B.C is 120 days.

[#715] With which of the following body organ is 'pace-maker' associated?
Correct Answer

(C) Heart

Explanation

Solution: Pacemaker is associated with heart. Pacemaker are implanted on the body of the patient to give artificial heart beat when the normal body heart beat fails to function in the body of the patient. They are implanted temporarily to treat a slow heartbeat after a heart attack, surgery or overdose of medication.