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Practice Questions (Short Answer)

Short Answer Questions  Question 1. Name the following (a) The process in plants that links light energy with chemical energy (b) Organisms that can prepare their own food (c) The cell organelle where photosynthesis occurs (d) Cells that surround a stomatal pore (e) Organisms that cannot prepare their own food (f) An enzyme secreted from g . . .

Practice Questions (Long Answer)

Long Answer Questions  Question 1. Explain the process of nutrition in Amoeba. Answer 1. Amoeba takes in food using temporary finger-like extensions of the cell surface which fuse over the food particle forming a food-vacuole (Fig. 6.5). Inside the foodvacuole, complex substances are broken down into simpler ones which then diffuse into . . .

Practice Questions (MCQ)

Multiple Choice Questions 1. Which of the following statements about the autotrophs is incorrect? (a) They synthesise carbohydrates from carbon dioxide and water in the presence of sunlight and chlorophyll (b) They store carbohydrates in the form of starch (c) They convert carbon dioxide and water into carbohydrates in the absence of sunlight (d) . . .

NCERT SOLUTIONS

Page - 95 Question 1: Why is diffusion insufficient to meet the oxygen requirements of multicellular organisms like humans? Answer 1: In multi-cellular organisms, all the cells may not be in direct contact with the surrounding environment. Thus, simple diffusion will not meet the requirements of all the cells. Question 2: What criteria . . .

Respiration

Respiration Respiration involves (i) Gaseous exchange : Intake of oxygen from the atmosphere and release of CO2 —? Breathing (ii) Breakdown of simple food in order to release energy inside the cell —?Cellular Respiration Breakdown of Glucose by various pathways Human Respiratory System Passage of air through the respirat . . .

Transportation in plants & animals

Transportation Human beings like other multicellular organism need regular supply of food, oxygen etc. This function is performed by circulatory system. Double circulation Blood travels twice through the heart in one complete cycle of the body. Pulmonary Circulation : Blood moves from the heart to the lungs and back to the heart. . . .

Excretion in plants & animals

EXCRETORY SYSTEM IN MAN Excretory/urinary system consists of : (1) The kidneys                          : The excretory organ (2) The ureters                           : The ducts which drain out urine from the kidneys (3 . . .

Chapter Synopsis

All living things perform certain life processes like growth, excretion, respiration, circulation etc. All the processes like respiration, digestion, which together keep the living organisms alive and perform the job of body maintenance are called life processes. . . .

Nutrition

Nutrition The whole process by which an organism obtain its food.  Some organisms use simple food material obtained from inorganic sources in the form of carbon dioxide and water. These organisms, the autotrophs, include green plants and some bacteria. Other organisms utilise complex substances. These complex substances have to be broken . . .

Blood Corpuscles (White Blood Cells)

White Blood Cells (Leukocytes) Structure Count 4000 – 8000 per mm3 Have nucleus, amoeboid in shape. Increase in the number of WBCs at the cost of RBCs is called Leukemia. Abnormal decrease in the number of WBCs is called Leukopenia. Production & death Produced in red bone marrow, lymph nodes & some time in li . . .

Air Pressure

Our earth is surrounded by a blanket of air called the atmosphere.The atmosphere extends up to nearly 300 km above the earth's surface. This air exerts pressure on everything on the earth. This pressure is called air pressure. Air pressure decreases with increasing altidute, that is, air pressure is more near the surface of the earth and decrease . . .

Thunderstorms

In hot and humid tropic areas like India, thunderstorms or lightning storms are known to occur. Thunderstorms are storm accompained by heavy rains , lightning, thunder and sometimes even snow and hail. when the air near the earth's surface heats up due to the heat of the sun , it rises upward. As the warm air moves up, it cools and condenses to form . . .

Advantages of using mercury in a thermometer

Advantages of mercury are: 1. It is opaque and shining. Hence , it is easily visible through the glass. 2. It does not wet the glass. 3. It has a low freezing point  and a high boiling point. It can be used over a wide range of temperatures. 4. It is a good conductor of hest, so it quickly absorbs heat to attain the temperature of the o . . .

Image formation in the eye

The human eye has an inbuilt convex lens. When the rays of light fall on the eye lens, it focuses a real and inverted image on the retina, which acts as a screen. The retina is connected to the optic nerves that carry the information to the brain. The brain then interprets the information and form s a real and erect image of the object with the correct . . .

Regular and irregular reflection

Regular Reflection Reflection that takes place through a regular and smooth surface is known as regular reflection. Irregular Reflection Reflection that takes place through a rough and dull surface is known as irregular or diffused reflection. . . .

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