521. Each turn of DNA contain ____________ nitrogenous base pairs?
A. 5
B. 10
C. 20
D. 25

522. Membranes of the grane are sites where?
A. Oxygen is stored
B. Food is stored
C. Sunlight is trapped
D. CO2 is stored.

523. Antibodies play important role against microorganisms and other pathogens to which type of proteins do they belong________?
A. Globular proteins
B. Fibrous Proteins
C. Both a and b
D. None of these

524. The simplest of oxygen producting photosynthetic organisms are____________?
A. Algae
B. Bacteria
C. Cyanobacteria
D. Chlamydomonas

525. Amphoixus is a__________?
A. Chordate
B. Protochordate
C. Lower chordate
D. All of these

526. Which structural organization is most common in globular proteins____________?
A. Primary
B. Secondary
C. Tertiary
D. Quaternary

527. Which of the following does not show quaternary structure____________?
A. Haemoglobin
B. Pepsin
C. Fibrin
D. Insulin

528. Which of the following occurs in anaerobic respiration but not in aerobic respiration?
A. Release of CO2
B. Reduction of NAD
C. Formation of ATP
D. Production of ethanol from acetaldehyde

529. helical structure is kept by the formation of _________ bonds among amino acids molecules?
A. H bonds
B. Disulphide Bond
C. Ionic bond
D. Hydrophobic bonds

530. Which of the following are triploblastic and acoelomate?
A. Sponges
B. Annelida
C. Platyhelminthes
D. Aves