Question

LUROVE 19. In Persistent infections, the cell harbors the virus which is not immediately lysed. This condition can be lor weeks or the host's lifetimes several viruses are known to periodically reactivate and multiply. penulient infections includes & Marsles vins which may remain hidden in brain cells for many years & Herpes simplex virus which are cold sores and genital herpes c Herpes zoster virus which causes chickenpox and shingles a all the above & none of the above 20. Not all bacteriophages complete the lytic gyde. Some DNA phages (called temperate phages) undergo adsorption and penetration but don't replicate. Instead, the viral genome inerts itself into bacterial genome (DNA) and becomes an inactive prophage -- the cell is not lysed The Prophage is retained and copied during normal cell division resulting in the transfer of temperate phage genome to all host all progeny. This process is + specificity & adsorption c alerriate pathway a lysogeny c ransformation 21. The cause of transmissible spongiform encephalopathies (they are fatal neurodegenerative diseas). Fumples are; Scrapie in shop and goats; Bovine spongiform encephalopathies (mad cow disewe), and Creutfeldt Jakob Syndrome and they contain RNA they contain viroids c all the above a none of the above 22. Nudlenses are enzymes that deuve (break) chemical bands in DNA & RNA. Nuclease do not damage; & animal viruses C viroids d bacteriophage influenza virus CHAPTER 7 23. Micronutrients are involved in enzyme function. Tor F 24. Inorganic nutrients contain aarbon and hydrogen atoms. Tor F 25. Autotrophs obtain carbon in an organic form. Tor F 26. Heterotrophs are organism that uses arbon dioxide. Tor F 27. Chemoheterotrophs derive both carbon and energy from organic compound Tor F 28. Regarding Transport (the movement of chemicals across the cell membrane), passive transport does not require energy, substances exist in a gradient and move from areas of higher concentration toward areas of lower concentration. Tor F 29. Regarding Transport (the movement of chemicals across the cell membrane), active transport requires energy and carrier proteins, and is gradient independent. Tor F 30. Active Transport is included in the process of phagocytosis Tor F prions

Answer 1

Answer 19 : “d” all the above

In the above infections the virus can remain latent in specific cells without causing any active infection for a long period of time.

Answer 20: “d” lysogeny

The bacterial viruses or the bacteriophages can undergo either of the two life cycles one is lytic and another one is lysogeny.

In lytic cycle the phage penetrates the host, takes over host’s machinery, synthesizes virus particles and lyse the cells, come out and infect other cells.

In lysogeny the phage penetrates the host cell but remain as a prophage in the bacterial chromosome,gets replicated along with the bacterial chromosome and pass on to the other bacterial cells, when the cell divides.

Answer 21: “d” None of the above

The cause of spongiform encephalopathics is believed to be ‘prions’ which are the protein molecules. Unlike the other infectious diseases the prions do not contain any nucleic acids like DNA or RNA.

Note: viroids are particles smaller than viruses, without the protein coat and only the nucleic acid(single stranded RNA). They are the plant pathogens.

Answer 22: “a” prions

Nucleases are the group of enzymes capable of cleaving nucleic acids like DNA/RNA.

Prions can not be destroyed by ordinary physical/chemical agents. Extremely high temperature for long period can destroy them. They are resistant to proteases(which can denature normal body proteins)

Answer 23: True Micronutrients are vitamins and minerals which are required as coenzymes or cofactors for enzyme action.

Answer 24: False Inorganic nutrients are micronutrients required for metabolic activities. They are the minerals like zinc, copper, iron etc. They do not contain carbon and hydrogen.

Answer 25: False Autotrophs obtain carbon in inorganic form. As the name suggests they are self feeding means they generate the organic form of carbon (glucose) with the help of sunlight,photosynthetic pigments and inorganic carbon source like carbon dioxide.

Answer 26: False Heterotrophs are the organisms which are dependent on the autotrophs for their source of organic nutrients, they can not use carbon dioxide.

Answer 27: True chemoheterotrophs means animals like us which can derive their energy from the organic nutrients, they consume.

Answer 28: True In passive transport the molecules move from their higher concentration to area of lower concentration without the expenditure of energy.

Answer 29: True   Sometimes the cell has to maintain the concentration of certain molecules inside it and hence these substances are taken from the outside environment even though their concentration is less outside. Since it is against the concentration gradient,cell has to spend energy to take the chemicals inside the cell. This is known as active transport.

Answer: 30 True In the process of phagocytosis, the cell has to take inside other cells ,large molecules or remains of the cells and digest them, hence this process requires ATP and hence it is an active transport.