Class 12 Biology - Chapter Microbes in Human Welfare NCERT Solutions | Bacteria cannot be seen with the naked e
Bacteria cannot be seen with the naked eyes, but these can be seen with the help of a microscope. If you have to carry a sample from your home to your biology laboratory to demonstrate the presence of microbes under a microscope, which sample would you carry and why?
Curd can be used as a sample for the study of microbes. Curd contains numerous lactic acid bacteria (LAB) or Lactobacillus. These bacteria produce acids that coagulate and digest milk proteins. A small drop of curd contains millions of bacteria, which can be easily observed under a microscope.
More Questions From Class 12 Biology - Chapter Microbes in Human Welfare
- Q:- Microbes can be used to decrease the use of chemical fertilisers and pesticides. Explain how this can be accomplished.
- Q:- Give examples to prove that microbes release gases during metabolism.
- Q:- Find out the role of microbes in the following and discuss it with your teacher.
(a) Single cell protein (SCP)
(b) Soil - Q:- Name any two species of fungus, which are used in the production of the antibiotics.
- Q:- How do biofertilisers enrich the fertility of the soil?
- Q:- What is sewage? In which way can sewage be harmful to us?
- Q:- Three water samples namely river water, untreated sewage water and secondary effluent discharged from a sewage treatment plant were subjected to BOD test. The samples were labelled A, B and C; but the laboratory attendant did not note which was which. The BOD values of the three samples A, B and C were recorded as 20mg/L, 8mg/L and 400mg/L, respectively. Which sample of the water is most polluted? Can you assign the correct label to each assuming the river water is relatively clean?
- Q:- In which food would you find lactic acid bacteria? Mention some of their useful applications.
- Q:- Name some traditional Indian foods made of wheat, rice and Bengal gram (or their products) which involve use of microbes.
- Q:- Arrange the following in the decreasing order (most important first) of their importance, for the welfare of human society. Give reasons for your answer.
Biogas, Citric acid, Penicillin and Curd
Popular Questions of Class 12 Biology
- Q:- Why is reproduction essential for organisms? Answer
- Q:- Name the parts of an angiosperm flower in which development of male and female gametophyte take place.
- Q:-
Fill in the blanks:
(a) Humans reproduce __________. (asexually/sexually)
(b) Humans are__________. (oviparous/viviparous/ovoviviparous)
(c) Fertilization is __________ in humans. (external/internal)
(d) Male and female gametes are __________. (diploid/haploid)
(e) Zygote is __________. (diploid/haploid)
(f) The process of release of the ovum from a mature follicle is called__________.
(g) Ovulation is induced by a hormone called the __________.
(h) The fusion of male and female gametes is called _____________.
(i) Fertilisation takes place in _____________.
(j) Zygote divides to form _____________which is implanted in uterus.
(k) The structure which provides vascular connection between fetus and uterus is called ____________. - Q:- What do you think is the significance of reproductive health in a society?
- Q:- Mention the advantages of selecting pea plant for experiment by Mendel.
- Q:- Group the following as nitrogenous bases and nucleosides:
Adenine, Cytidine, Thymine, Guanosine, Uracil and Cytosine. - Q:- Explain antibiotic resistance observed in bacteria in light of Darwinian selection theory.
- Q:- What are the various public health measures, which you would suggest as safeguard against infectious diseases?
- Q:- Explain in brief the role of animal husbandry in human welfare.
- Q:- Can you list 10 recombinant proteins which are used in medical practice? Find out where they are used as therapeutics (use the internet).
Recently Viewed Questions of Class 12 Biology
- Q:- Why is reproduction essential for organisms? Answer
- Q:- If a double stranded DNA has 20 per cent of cytosine, calculate the per cent of adenine in the DNA.
- Q:-
Mention two strategies evolved to prevent self-pollination in flowers.
- Q:- Explain antibiotic resistance observed in bacteria in light of Darwinian selection theory.
- Q:- A child has blood group O. If the father has blood group A and mother blood group B, work out the genotypes of the parents and the possible genotypes of the other offsprings.
- Q:- How is sex determined in human beings?
- Q:- Diagrammatically represent the experimental steps in cloning and expressing an human gene (say the gene for growth hormone) into a bacterium like E. coli ?
- Q:- State True/False with explanation
(a) Abortions could happen spontaneously too. (True/False)
(b) Infertility is defined as the inability to produce a viable offspring and is always due to abnormalities/defects in the female partner. (True/False)
(c) Complete lactation could help as a natural method of contraception. (True/False)
(d) Creating awareness about sex related aspects is an effective method to improve reproductive health of the people. (True/False) - Q:- Define phenotypic adaptation. Give one example.
- Q:- Name the primary and secondary lymphoid organs.
- All Chapters Of Class 12 Biology
- All Subjects Of Class 12