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Std XI Cell

1. Bone digestors or osteoclasts are rich in  a) lysosomes b) vacuole c) Golgi complex d) E.R. 2. The smallest living cells with the cell wall are  a) viriods b) protista c) mycoplasma d) bacteria 3. Microtubules are the constituents of a) cilia,flagella and peroxisomes b) spindle fibres,centrioles and cilia c) centrioles, spindle fibres and chromatin d) centrosome,nucleosome and centrioles 4. Mitochondria and chloroplast are i) semi-autonomous organelles ii) formed by division of pre existing organelles and they contain DNA but lack protein synthesising machinery. a) both are correct b) i is true but ii is false c) ii is true but i is false d) both are false 5. The spherical head of the oxysome is  a) dictyosome b) F1 subunit c) F0 subunit d) granum

Reproduction in humans

1.In human males, the testes lie in the scrotum, because it helps in the (a) process of mating (b) formation of sperms (c) easy transfer of gametes (d) secretion of estrogen 2. Which among the following diseases is not sexually transmitted? (a) Syphyllis (b) Hepatitis (c) HIV-AIDS (d) Gonorrhea 3. Which of the following method of contraception protects from acquiring sexually transmitted diseases? (a) Surgery (b) Condoms (c) Copper-T (d) Oral-pills 4. The embryo in humans gets nutrition from the mother’s blood with the help of a special tissue called (a) Placenta (b) Villi (c) Uterus (d) Womb 5. Along the path of the vas-deferens the secretions of which gland provide nutrition to the sperms? (a) Prostate glands (b) Seminal vesicles (c) Scrotum (d) Urinary bladder 6. In human beings, the fertilization occurs in the (a) uterus (b) ovaries (c) fallopian tubes (d) vagina 7. The period during adolescence when the reproductive tissues begin to mature is called (a) ovyfetion (b) puberty (c) ...

Cell IX

1.Write four differences between prokaryotic and eukaryotic cells. 2. What will happen if cell is arrested at meiosis during gamete formation? 3. Write two similarities and two dissimilarities between mitochondria and plastids. 4. Why is salt added to raw fruits and vegetables before making pickles? 5. Write four functions of endoplasmic reticulum.