Download App

Microbes in Human Welfare — BIOLOGY STD 12 Science — Question

Rajasthan BoardEnglish MediumSTD 12 ScienceBIOLOGYMicrobes in Human Welfare4 Marks
Question
Microbes are useful in household products. Explain this with suitable examples
✓

Answer

We use microbes. Our products are derived from them everyday.
(1) Curd: LABs are lactic acid bacteria.
→ They grow in milk and convert it to curd.
→ During growth, the LAB produce acids that coagulate and partially digest the milk proteins.
→ A small amount of a curd added to the fresh milk as inoculum or starter contain millions of LAB, which at suitable temperatures multiply, thus converting milk to curd.
→ LAB improves milk quality by increasing vitamin B12.
→ In our stomach too, the LAB play very beneficial role in checking diseases causing microbes.
2. Cheese:
→ Cheese is an edible substance. Microbes are used at different stages of cheese. making.
→ Different varieties of cheese are known by their characteristic texture, flavour and taste which is given by specific microbes used in the cheese production.
→ The large holes in "swiss cheese" are due to production of a large amount of carbon dioxide by a bacterium named Propionibacterium sharmanii.
→ The "Roquefort cheese" are ripened by growing a specific fungi on them, which gives them a particular flavour.
3. Batter:
→ The batter of dosa and idli is fermented by using bacteria. This batter looks puffed because of the production of carbon dioxide.
→ The dough, which is used for making bread, is fermented using saccharomyses cerevisiae- baker's yeast.
4. Toddy:
→ Some traditional drink and food is also produced by the help of microbes through fermentation.
→ In South India, traditional drink toddy is made by fermenting sap from palms.
5. Other food items:
→ To produce different food items fish, soyabean, bamboo etc. are passed through fermentation.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "Case study (4 Marks)" from Microbes in Human Welfare→Microbes in Human Welfare — all question types→BIOLOGY STD 12 Science question papers→Rajasthan Board STD 12 Science question papers→Rajasthan Board question paper generator→

Similar questions

Read the following and answer any four questions from (i) to (v) given below:

A woman unable to conceive after many years of regular unprotected coitus went to specialised infertility clinic. On complete examination, woman was found to be normal, while male partner was diagnosed with infertility. Male partner is unable to copulate the female. Couple was advised to opt for assisted reproductive technology (ART).

  1. Which ART could have been useful for this couple?
  1. ZIFT
  2. IUT
  3. AI
  4. GIFT
  1. In which of the following infertility issues could this technique be used?
  1. Anovulation.
  2. Oligospermia.
  3. Low fructose content in seminal fluid.
  4. All of these.
  1. Which among the following techniques is useful to conceive when there is very low sperm count?
  1. GIFT
  2. Test-tube baby
  3. IUT
  4. JCSI
  1. Assertion: Artificial insemination (AI) is intra-uterine insemination.

Reason: In Al, sperms collected from donor are introduced into the uterus.

  1. Both assertion and reason are true, and reason is the correct explanation of assertion.
  2. Both assertion and reason are true, but reason is not the correct explanation of assertion.
  3.  Assertion is true, but reason is false.
  4. Both assertion and reason are false
  1. Success rate of artificial insemination technique is:
  1. 20-40%
  2. 60-70%
  3. 40-50%
  4. 5-7%
→
  1. What are the three options that can be thought of, to increase food production?
  2. Mention the reasons for the success of Green Revolution in increasing food production.
  3. Why do we still search for other alternatives to increase food production?
→
Explain structure and working of biogas plant with diagram.
→
Explain the amplification of gene of interest using PCR (Diagram is must)
→
Read the following and answer any four questions from (i) to (v) given below:

In a study to test a new vaccine against a viral disease, mouse model testing is done. In this process, mice are vaccinated and their blood samples were tested. Mice developed mild disease symptom. After few days those mice were again infected with the virus. This time they do not show any disease symptoms. Their blood samples were tested. Two graphs show antibody concentration for the first and second infection in mice blood.

Based on the above information, answer the following questions.

  1. P and Qin the given graphs indicate.
  1. IgM and IgG respectively.
  2. IgG and IgM respectively
  3. IgG and IgM respectively
  4. IgM and IgA respectively.
  1. Which form of pathogen is used in vaccination?
  1. Activated and strong pathogenic antigen.
  2. Inactivated and weakened pathogenic antigen.
  3. Hyperactive and strong pathogen.
  4. Preformed antibodies.
  1. Which of the following is incorrect for P?
  1. It is the most abundant class of lg.
  2. It is found in blood, lymph, and intestine.
  3. It is unable to cross the placental barrier.
  4. It is a monomer.
  1. How does vaccination work?
  1. The immune system produces antibodies which stay in the blood.
  2. Memory lymphocytes remain in the body to fight off any future infection with the same pathogen.
  3. The dead pathogen stays in the body and constantly stimulates the immune system.
  4. All of these.
  1. Assertion: Mice do not show any disease symptoms during second exposure to the pathogenic virus.

Reason: The antibody production is accelerated and more intense during secondary immune response.

  1. Both assertion and reason are true, and reason is the correct explanation of assertion.
  2. Both assertion and reason are true, but reason is not the correct explanation of assertion.
  3. Assertion is true, but reason is false.
  4. Both assertion and reason are false.
→
Describe tissue culture.
→
Read the following and answer any four questions from (i) to (v) given below:

Priya was 4 years old when she contracted chicken pox. It took her around 15 days to recover completely. Now Priya is 5 years old, so her mother got her vaccinated few days back for DPT (5th dose) as per immunisation program. Recently she was playing with her friend in the park when her friend accidently fell on iron pipe and badly bruised her knee. She was taken to the hospital where doctor gave her ATS injection and painkillers. Based on the above information, answer the following questions.

  1. Select the correct statement.
  1. Priya has developed natural active immunity against chicken pox.
  2. Priya has developed artificial active immunity against DPT.
  3. Priya's friend has developed artificial passive immunity against tetanus.
  4. All of these
  1. Which of the following do you think is an example of natural passive immunity?
  1. Administration of AGS (anti gas gangrene serum) in a person.
  2. Transfer of IgA antibodies from mother to baby through mother's milk.
  3.  A person recovered from viral infection.
  4. A child vaccinated for polio.
  1. Which of the following is true for active immunity?
  1. It provides immediate relief.
  2. It is temporary, not long lasting
  3. It has no side effects.
  4. None of these
  1. Select the incorrect match.
  1. Passive immunity-IgG antibodies crossing placental barrier to reach fetus.
  2. Active immunity-Vaccination against corona virus.
  3. Active immunity-Administration of antidiphtheria serum in patient.
  4. Passive immunity-Fetus having mother's milk.
  1. Assertion: A person recovered from measles develops an active immunity against this infection.

Reason: In active immunity, person's own cells develop antibodies in response to infection.

  1. Both assertion and reason are true and reason is the correct explanation of assertion.
  2. Both assertion and reason are true, but reason is not the correct explanation of assertion.
  3. Assertion is true, but reason is false.
  4. Both assertion and reason are false.
→
Read the following and answer any four questions from (i) to (v) given below:

Within a region, species richness increases with increasing explored area, but only upto a limit. TI1e given graph explains this relationship.

  1. What does the given figure show?
  1. Rivet-popper hypothesis.
  2. Species-area relationship.
  3. Proportionate number of species of major taxa.
  4. $\alpha-\text{ecological diversity }$
  1. Equation for relationship (A) between species richness and area is:

  1. $\log\text{ S}=\log\text{ C}+\text{Z }\log\text{ A}$

  2. $\log\text{ C}=\log\text{ S}+\text{Z }\log\text{ A}$

  3. $\text{Z }\log\text{ A}=\log\text{ S}+\log\text{ C}$

  4. $\log\text{ S}=\log\text{ C}+\log\text{ A}$

  1. What is the value of slope of line or regression coefficient Z for frugivorous birds?
  1. 0.1 - 0.2
  2. 1.15
  3. 0.01 - 0.1
  4. 0.6 - 1.2
  1. The shape of curve for relationship between species richness and areas for wide variety of taxa is:
  1. Straight line.
  2. Parabola.
  3. Rectangular hyperbola.
  4. Bell shaped.
  1. Who gave this concept of increase in species richness with increasing offered area?
  1. Humboldt.
  2. Odum.
  3. Edward Wilson.
  4. Paul Ehrlich.
→
Explain pBR322 with its cloning sites, enzymes with well labeled diagram.###Explain: cloning sites. (Diagram is not necessary)
→
Define decomposition and describe the processes and products of decomposition.###Describe factor affecting decomposition.
→