Question

Q1) Name the bacterium that is useful in making curd from milk.

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Q2) How bacteria convert milk into curd?

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Q3) Name the micro-organism which is used to prepare bread, cake, etc.

1

Q4) Why dough rises?

2

Q5) Define fermentation.

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A) Seeds need water (in the form of moisture) to germinate. Plants need water to draw nutrients from the soil,

for their growth and for making food by photosynthesis. To maintain the moisture of the soil for healthy

crop growth, the fields should be watered at proper intervals. The watering of plants at different interval is

called irrigation. The timer and frequency of irrigation vary from crop to crop, soil to soil and season to

season.

The frequency of irrigation in summer is higher due to increased rate of evaporation of water from the soil

as well as from the leaves. Sandy soil needs more water than the clayey soil. Wheat, gram and cotton need

irrigation at regular intervals, but not the standing water. Paddy (rice) is transplanted in standing water and

need continuous irrigation. Water for irrigation can be obtained from wells, tube wells, ponds, lakes, river,

dams etc.

Q1) Define irrigation.

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Q2) Why plants need water?

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Q3) In which season irrigation should be done more frequently?

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Q4) Name two plants which do not need standing water.

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Q5) Name two source of irrigation.

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Q5) Draw diagram and answer the following questions:

[2×3=6]

A) Draw diagram of candle flame and label A, B, C

1. Name the hottest zone of candle flame.

2.Which is the zone of no combustion

B) Draw flowchart for classification of microorganisms and answer the following questions

1. Simplest microorganisms.

2. Unicellular organisms which are heterotrophs

3. Organisms which are neither living nor nonliving.

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Answer 1

Explanation:

Curd contains several microorganisms. Of these, the bacterium,

Lactobacillus promotes the formation

of curd. It multiplies in milk and

converts it into curd. Bacteria are also

involved in the making of cheese,

pickles and many other food items. An

important ingredient of rava (sooji )

idlis and bhaturas is curd. Can you

guess why? Bacteria and yeast are also

helpful for fermentat

Answer 2

Answer:

Milk converts to curd due to the production of lactic acid. This process of conversion of milk to curd occurs due to the action of bacteria Lactobacillus that form lactic acids from sugars present in the milk.