Ch 2 Microorganism Assignment 1 PDF

DELHI PUBLIC SCHOOL- BOPAL, AHMEDABAD CLASS: VIII ASSIGNMENT-1 MICROORGANISMS: FRIENDS AND FOE Multiple Choice Questions: 1 The gas released during the preparation of bread is: (a) Oxygen (b) Carb...

DELHI PUBLIC SCHOOL- BOPAL, AHMEDABAD CLASS: VIII ASSIGNMENT-1 MICROORGANISMS: FRIENDS AND FOE Multiple Choice Questions: 1 The gas released during the preparation of bread is: (a) Oxygen (b) Carbon dioxide (c) Nitrogen (d) Sulphur dioxide 2 Which of the following helps in making curd from milk? (a) Lactobacillus (b) Plasmodium (c) Yeast (d) Salmonella 3 A disease in human beings caused by virus is _______. (a) Typhoid (b) Influenza (c) Dysentry (d) Cholera 4 Select the correct answer to these questions from the options as given below: (a) Both A and R are true and R is the correct explanation of the assertion. (b) Both A and R are true but R is not the correct explanation of the assertion. (c) A is true but R is false. (d) A is false but R is true Assertion (A): Bacteria are harmful for curd. Reason (R): Milk is converted into curd by Lactobacillus. 5 Assertion: The replenishment of soil with nutrients is done by some microorganisms. Reason: Fungi and bacteria are common decomposer. 6 Assertion: Malaria, Dengue can be prevented by using mosquito net and mosquito repellent. Reason: The causative organism spread through contaminated food and water. 7. Match the diseases with their respective pathogens: List-1 (Pathogen) List-2 (Disease) (A) Fungus (i) Cholera (B) Protozoan (ii) Ringworm (C) Bacteria (iii) AIDS (D) Virus (iv) Malaria 8 Fill in the blanks: (a) The female Aedes mosquito is a carrier of the ________disease. (b) _______, ______ are chemicals that inhibit microbial growth. (c) ________ is a unicellular fungus. (d) ________ made the first vaccine. 9 Municipal Corporation has deputed to check for mosquito breeding in your school. (a) Name two diseases which are spread by mosquitoes. (b) Mention two ways to control the growth of mosquitoes and their larvae. 10 What is food poisoning and how we can prevent it? 11 Discuss two important ways in which bacteria are useful to us and two ways in which they are harmful. 12 Why do you think: (a) Curd sets faster in summer than in winter? (b) Curd turns sour faster in summer than in winter? (c) The sealed packets in which food items such as chips are sold are usually filled with nitrogen. 13 We should not use the towel, utensils of a person suffering from tuberculosis. (a) What does this statement mean? (b) What are the various indirect methods of transmission of communicable disease? (c) Give the names of some carriers that transmit communicable disease 14 Identify the given organisms: 15 Microorganisms decompose the organic matter and help to clean the environment. a) How does a microbe help in cleaning the environment? b) What would happen if microorganisms do not perform this function? 16 Give one example of the following: c) A protozoan showing photosynthesis d) A filamentous alga e) A single celled fungus 17 Describe the principal on which the following method of food preservation are based. f) Boiling g) Canning h) Freezing i) Dehydration 18 Identify a, b, c, d. 19. Examine the data and answer the questions that follow: The temperature and of the organism's body may have an effect on the growth patterns of many species of viruses. A study of viral reproduction was under taken by a local university. It measured the temperature of the organism and the change viral number over a 2 day period. The results of the study are found in the data table below. (a) At what temperature did virus A develop the best? (b) Based on the above data, what temperature(s) seem to be the best for viral development? (c) What term is used if the temperature in a human goes above 98.6 degrees F? (d) Virus cannot replicate alone. Viruses must infect cells and use components of the host cell to make copies of themselves. Often, they kill the host cell in the process, and cause damage to the host organism. At what temperature(s) would the most cell destruction take place for Virus A? Why? (e) Can viruses be killed by antibiotics?