Selina solutions concise biology class 9 icse Solutions for Chapter 9 economic importance of bacteria and fungi

Exercises in Chapter 9 economic importance of bacteria and fungi Grade 9

Exercise

Questions in Exercise

Name the three common shapes of bacteria

Give the technical terms for the following patterns of occurrence of bacteria (i) In pairs ________ (ii)In long chains ____________ (iii)In clusters ____________

List the kinds of nutrition in bacteria

What is the common method of reproduction in bacteria?

Why do bacteria produce spores?

Bacteria are no more classified as plants primarily because: (a) These are unicellular (b) These are microscopic (c) Many of them are parasitic (d) They have no chlorophyll

A particular species of which one of the following, is the source bacterium of the antibiotic, discovered next to penicillin, for the treatment of tuberculosis? (a) Escherichia (b) Streptomyces (c) Rhizobium (d) Nitrobacter

Which bacteria is rod shaped?

(a) Coccus

(b) Spirillum

(d) Vibrio

Which bacteria fixes nitrogen in the soil?

(a) Nitrobacter

(b) Nitrosomonas

(d) Clostridium

Name the three common types of bacteria

Match the items in Column A with those in Column B.

Column A Column B

(i) Penicillium (a) Bacteria occurring in chains.

(ii) Diplococci (b) Antibiotic

(iii) Streptococci (c) Bacteria occurring in pairs

Would you consider the bacteria and yeast as plants? Give reason.

In what form bacteria may be present in the air?

Why is spore formation in bacteria not considered a form of reproduction?

In what respect do you consider bacteria as simple organisms?

State the differences between (a) Decay and putrefaction. (b) Pasteurization and sterilization of food/objects/equipments

Why is it generally advised that every living room in the house should get direct sunlight at least for a short time?

Would there be any bacteria in an aquarium?

Both bacteria and yeast reproduce by asexual method, but how does this method differ in them?

Describe the role of micro-organisms in industrial production

How do bacteria obtain their nourishment?

Describe any two uses of bacteria in industry

What are antibiotics? Name any two examples.

Is tinned and sealed food always safe to eat? Give reasons in support of your answer.

Study the diagram given below and then answer the questions that follow:

(a) Briefly describe how nitrogen of the atmosphere is converted to nitrates by leguminous plants.

(b) Name the bacteria that converts

(i) Ammonium compounds to nitrites

(ii) Nitrites to nitrates

(d) Role of plants and animals in the formation of ammonium compounds.

Which is the most common variety of cultivated mushroom? ___________

What is meant by “mushroom seed”? ___________

What is done in the step called “casing”? ___________

Production of ethanol (C2H5OH) occurs in one of the life processes of:

(a) Bread mould

(b) Yeast

(d) Penicillin

Which one of the following characteristics is found in all fungi but not in all bacteria?

(a) Aerobic respiration

(b) Cell wall

(d) A long circular DNA lying loose in the cytoplasm.

Bacteria are referred to as prokaryotes because:

(a) They have no chlorophyll

(b) They are unicellular

(d) They do not have a true nucleus

Yeast is used in the production of:

(a) Ethyl alcohol

(b) Acetic acid

(d) curd

Tick mark the correct statement/statements (a) All mushrooms are poisonous And Fungi (b) All toadstools are poisonous (c) Some toadstools are poisonous (d) Some mushrooms are edible

Where can the mould Rhizopus be most easily found?

Why is it generally advised that every living room in the house should get direct sunlight at least for a short time?

Describe the role of certain fungi in industrial production

Mention two useful and two harmful effects of wine.

Differentiate between: (a) Saprophyte and Parasite (b) Aerobic and anaerobic respiration with regard to products (c) Decay and putrefaction.

What are antibiotics? Name any two examples.

Is tinned and sealed food always safe to eat? Give reasons in support of your answer.

Would there be any bacteria in an aquarium?

If you leave a piece of moist bread covered under a small bell jar at a warm place, mould grows on it in a few days. Answer the following with reference to this observation:

(a) How did the mould get inside the bell-jar?

(b) What would happen if the bread was not covered by the bell-jar?

(d) What appears first on the bread – the mycelia or the spores?

(e) How does bread mould obtain nourishment? What type of nourishment is it –

epiphytic, autotrophic, parasitic symbiotic, or saprophytic?

Write in proper sequence the five major steps in the cultivation of the common edible mushroom.

Comment on the following: (a) Denitrifying bacteria are a blessing as well as a curse to farmers. (b) Yeast is used in bakeries and breweries