481. The following points about microfilamentsare true except(
A. They form cytoskeleton with microtubules
B. They provide support and shape
C. They form intracellular conducting channels
D. They are involved in muscle cell contraction

482. The following substances are cellinclusions except
A. Melanin
B. Glycogen
C. Lipids
D.Centrosome

483. Fatty acids can be transported into andout of cell membrane by
A. Active transport
B. Facilitated transport
C. Diffusion
D. Osmosis

484. Enzymes catalyzing electron transportare present mainly in the
A. Ribosomes
B. Endoplasmic reticulum
C. Lysosomes 

 D. Inner mitochondrial membrane

485. Mature erythrocytes do not contain
A. Glycolytic enzymes
B. HMP shunt enzymes
C. Pyridine nucleotide
D. ATP

486. In mammalian cells rRNA is producedmainly in the
A. Endoplasmic reticulum
B. Ribosome
C. Nucleolus
D. Nucleus

487. Genetic information of nuclear DNA istransmitted to the site of protein synthesisby(
A.rRNA
B. mRNA
C. tRNA
D.Polysomes

488. The power house of the cell is
A. Nucleus
B. Cell membrane
C. Mitochondria
D. Lysosomes

489. The digestive enzymes of cellularcompounds are confined to
A. Lysosomes
B. Ribosomes
C. Peroxisomes
D.Polysomes

490. Which of the following organic groups are found in naturally occuring amino acids?
A. Guanidinium ion
B. Indole
C. Imidazole
D. All of these