Ozone depletion occurs commonly due to_______________?
A. Carbon dioxide
B. Chlorofluorocarbons
C. UV rays
D. Deforestation
Biology Mcqs
Deoxygenated blood first enters in _________ part in fishes?
Deoxygenated blood first enters in _________ part in fishes?
A. Sinus venosus
B. Right atrium
C. Left atrium
D. Conus arteriosus
According to cohesion-tension theory, tension is created by__________________?
According to cohesion-tension theory, tension is created by__________________?
A. Hydrogen bonding
B. Transpiration
C. Adhesion
D. Root prerssure
Cuticular transpiration is _____________ of total transpiration?
Cuticular transpiration is _____________ of total transpiration?
A. 1-2%
B. 3-4%
C. 5-7%
D. 90%
An infectious disorder of respiratory system is_________________?
An infectious disorder of respiratory system is_________________?
A. Cancer
B. Asthma
C. Tuberculosis
D. Emphysema
_________________ cells of phloem are directly involved in transport of organic solutes?
_________________ cells of phloem are directly involved in transport of organic solutes?
A. Parenchyma
B. Companion cell
C. Tracheid
D. Sieve element
95% of the cytoplasm of RBCs is____________?
95% of the cytoplasm of RBCs is____________?
A. Hemoglobin
B. Enzymes
C. Salts
D. Other proteins
An antibody is made of _________ polypeptide chains?
An antibody is made of _________ polypeptide chains?
A. 1
B. 2
C. 3
D. 4
______________ of earth surface is covered with water?
______________ of earth surface is covered with water?
A. 10%
B. 30%
C. 75%
D. 90%
Gaseous exchange in birds occurs at level of_______________?
Gaseous exchange in birds occurs at level of_______________?
A. Alveoli
B. Air sacs
C. Bronchi
D. Parabronchi