371: Metals used in voltaic cell are:
(a) Zinc and lead
(b) Carbon and zinc
(c) Zinc and copper
(d) Carbon and nickel
372: With regard to the transmission of the Human Immuno deficiency Virus, which one of the following statements is not correct ?
(a) The chance of transmission from female to male are twice as likely as from male to female
(b) The chances of transmission are more if a person suffers from other sexually transmitted infections
(c) An infected mother can transmit the infection, at childbirth and by breast feeding
(d) The risk of contraction infection from transfusion of infected blood is much higher than an exposure to contaminated needle
Explanation:
According to European Study Group on Heterosexual Transmission of HIV, overall 19 (12%) male partners and 82 (20%) female partners were infected with HIV, suggesting that to female transmission is 1.9 (95% confidence interval 1.1 to 3.3) times more effective than female to male transmission.
Having a sexually transmitted disease (STD) can increase a person's risk of becoming infected with HIIV.
The main routes of HIV transmission are through :
- Unportected sexual contact with an infected person
- By sharing needles with an infected person and
- From an infected mother to child during pregnancy, during birth or shortly after birth while breastfeeding.
(Blood for blood transfusions is checked for the virus, and is not a major risk for transmission anymore).
HIV infection through blood transfusion has higher probability that by infected needled. 'For the virus to be transmitted, it has to freshly taken in the syringe and the anti-coagulants had to be maxed.
The virus stays fresh till the blood is moist and it has to injected immediately on a person. But in the hot climates the virus cannot survive outside for long'.
373: Metastasis is the process by which
(a) cells divide rapidly under the influence of drugs
(b) cancer cells spread through the blood or lymphatic system to other sites or organs
(c) the chromosomes in cell nuclei are attached to the spindle before moving to the anaphase poles
(d) cancer cells are successfully inhibited to divide any further
Explanation:
The spread of cancer cells through blood or lymphatic system after breaking off from the original tumour to other parts of the body is called 'Metastasis'. The tumours that are formed from the spreaded cells are called 'Secondary tumours'.
374: Which one of the following techniques can be used to establish the paternity of a child ?
(a) Protein analysis
(b) Chromosome counting
(c) Quantitative analysis of DNA
(d) DNA finger-printing
Explanation:
DNA finger printing technique is used to establish the paternity of a child, criminal identification in murder and rape cases etc. DNA finger printing is a genetic diagnostic testing also known as 'DNA typing' in which specific repeatable sequences of DNA bases (mini satellites) are identified, analysed and imaged using synthetically prepared artificial radioactive probes.
375: Vitamins do not act as a/an:
(a) Source of energy
(b) Stimulant in the growth of the body
(c) Agent in regulating the chemical processes in the body metabolism
(d) All of the above