Question

Q-5 Answer the following in one sentence (5×1=5)

1. Mention any one function of lysosome.

2. Write any two conditions necessary for combustion to take

place.

3. Why is white phosphorous stored in water ?

4. Define food preservation.

5. What is known as altitude?

Q-6

A. Complete the given paragraph (4×0.5=2)

In _____ , Robert Hooke discovered the cell. He observed

slice of cork under a _______. He draw what he could see

and published the pictures in a book called ________ . He

gave the term _____ to each box.

B. State true or false . Rewrite the false statements correctly

(3×1=3)

1. Crop rotation reduces soil fertility.

2. A good fuel has high calorific value.

3. Cell membrane is a thin porous membrane that separates

the nucleus from cytoplasm.​

Answer 1

Answer:

1.A lysosome has three main functions: the breakdown/digestion of macromolecules (carbohydrates, lipids, proteins, and nucleic acids), cell membrane repairs, and responses against foreign substances such as bacteria, viruses and other antigens. ... The lysosome's hydrolytic enzymes then destroy the pathogen.

2.Three things are required in proper combination before ignition and combustion can take place---Heat, Oxygen and Fuel. There must be Fuel to burn. There must be Air to supply oxygen. There must be Heat (ignition temperature) to start and continue the combustion process.

3.White phosphorus is highly reactive, and spontaneously ignites at about 30°C in moist air. It is usually stored under water, to prevent exposure to the air. It is also extremely toxic, even in very small quantities.

4.Food preservation prevents the growth of microorganisms, or other microorganisms, and slowing the oxidation of fats that cause rancidity. Food preservation may also include processes that inhibit visual deterioration, such as the enzymatic browning reaction in apples after they are cut during food preparation.

5.As a general definition, altitude is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. ... Although the term altitude is commonly used to mean the height above sea level of a location, in geography the term elevation is often preferred for this usage.

6. A. 1655

microscope

micrographia

B. False

true

False

Answer 2

Answer:

1. Lysosomes contain hydrolytic enzymes of acidic pH which helps to destroy foreign particles or worn out cells.
2. Presence of Oxygen and and presence of fuel with optimum ignition temperature is necessary.
3. White Phosphorus is very reactive and ignites instantaneously at around 30°C. So to prevent direct contact with air (O2) it is stored in water.
4. Food preservation refers to the technique of preventing food spoilage by checking unwanted microbial growth in food. Rancidity can be prevented by storing food in airtight containers.
5. (I couldn't understand your question). Altitude refers to the height of a place above sea level.
6. A. 1665 , microscope, Micrographia, "cellula"(Latin).

B. 1. False

2.True

3.False