Test: Class 7 General Science NCERT Based - 1


15 Questions MCQ Test Science & Technology for UPSC CSE | Test: Class 7 General Science NCERT Based - 1


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This mock test of Test: Class 7 General Science NCERT Based - 1 for UPSC helps you for every UPSC entrance exam. This contains 15 Multiple Choice Questions for UPSC Test: Class 7 General Science NCERT Based - 1 (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: Class 7 General Science NCERT Based - 1 quiz give you a good mix of easy questions and tough questions. UPSC students definitely take this Test: Class 7 General Science NCERT Based - 1 exercise for a better result in the exam. You can find other Test: Class 7 General Science NCERT Based - 1 extra questions, long questions & short questions for UPSC on EduRev as well by searching above.
QUESTION: 1

Match the List-I with List-II and select the correct answer using the code given below :

 

Solution:
  • The inner lining of the stomach secretes mucus, hydrochloric acid and digestive juices. Mucus protects the lining of the stomach. The hydrochloric acid kills many bacteria that enter along with the food and makes the medium in the stomach acidic and helps the digestive juices to act.

  • Digestive juices break down the proteins into simpler substances The digested food can now pass into the blood vessels through the wall of the small intestine. This process is called absorption.

  • The large intestine absorbs water and some salts from the undigested food material. The liver is the largest gland in the body. It secretes bile juice that is stored in a sac called the gallbladder. Bile plays an important role in the digestion of fats.

QUESTION: 2

Regarding amoeba, consider the following assertions:

1. It is a microscopic single-celled organism found in pond water.

2. Amoeba constantly changes its shape and position.

3. Amoeba has a cell membrane, a rounded, dense nucleus and many small bubble-like vacuoles in its cytoplasm.

Which of the above assertions is/are correct?

Solution:
  • It is the microscopic unicellular organism found in pond water which keeps changing its shape and position constantly. It has a cell membrane, a rounded, dense nucleus and many small bubble-like vacuoles in its cytoplasm.

  • The amoeba is a tiny, one-celled organism. You need a microscope to see most amoebas – the largest are only about 1 mm across. Amoebas live in freshwater (like puddles and ponds), in salt water, in wet soil, and in animals (including people). There are many different types of amoebas.

  • The name amoeba comes from the Greek word amoibe, which means change. (Amoeba is sometimes spelled ameba.)

    1. Cell membrane – the thin layer of protein and fat that surrounds the amoeba; it allows some substances to pass into the cell, and blocks other substances.

    2. Contractile vacuole – a cavity within the amoeba that excretes excess water and waste; the waste is brought to the cell membrane and is then eliminated from the amoeba.

    3. Cytoplasm (ectoplasm and endoplasm) – a jelly-like material that fills most of the cell; the organelles (like the nucleus) are surrounded by cytoplasm.

    4. Food vacuole – a cavity within the amoeba in which food is digested (broken down in order to be absorbed by the amoeba).

    5. Nucleus – the major organelle of the amoeba, located centrally; it controls reproduction (it contains the chromosomes) and many other important functions (including eating and growth).

    6. Pseudopods – temporary “feet'' that the amoeba uses to move around and to engulf food. An amoeba consists of a single blobby cell surrounded by a porous cell membrane.

    The amoeba “breathes” using this membrane – oxygen gas from the water passes into the amoeba through the cell membrane and carbon dioxide gas leaves through it. A complex, jelly-like series of folded membranes called cytoplasm fills most of the cell. A large, disk-shaped nucleus within the amoeba controls the growth and reproduction of the amoeba.

QUESTION: 3

Which of the following assertions is/are correct?

1. The liver is the largest gland in the body.

2. The liver does not secrete bile juice.

3. Bile juice plays an important role in the digestion of fat.

Use the code given below to select the correct answer-

Solution:
  • The liver is an abdominal glandular organ in the digestive system. It is located in the right upper quadrant of the abdomen, under the diaphragm and on top of the stomach. The liver is a vital organ that supports nearly every other organ to some capacity.

  • The liver is the body's second-largest organ (skin is the largest organ. Function: "The liver has a complex role in the function of the body," said Jordan Knowlton, an advanced registered nurse practitioner at the University of Florida Health Shands Hospital.

  • "Detoxification, metabolism (including regulation of glycogen storage), hormone regulation, protein synthesis, digestion, and decomposition of red blood cells, to name a few."

    • Production of bile, which helps carry away waste and break down fats in the small intestine during digestion.

    • Production of certain proteins for blood plasma.

    • Production of cholesterol and special proteins to help carry fats through the body

    • Conversion of excess glucose into glycogen for storage (glycogen can later be converted back to glucose for energy) and to balance and make glucose as needed

    • Regulation of blood levels of amino acids, which form the building blocks of proteins

    • Processing of hemoglobin for use of its iron content (the liver stores iron)

    • Conversion of poisonous ammonia to urea (urea is an end product of protein metabolism and is excreted in the urine)

    • Clearing the blood of drugs and other poisonous substances

    • Regulating blood clotting

    • Resisting infections by making immune factors and removing bacteria from the bloodstream

    • Clearance of bilirubin, also from red blood cells. If there is an accumulation of bilirubin, the skin and eyes turn yellow.

QUESTION: 4

Regarding the digestive system, consider the following assertions:

1. Digestive juices convert simple substances of food into complex ones, which is helpful in digestion.

2. The inner walls of the stomach, the small intestine, and the various glands associated with the alimentary canal secrete digestive juices.

Which of the above assertions is/are wrong?

Solution: Digestive juices convert complex substances of food into simpler ones. The digestive tract and the associated glands together constitute the digestive system. The inner walls of the stomach and the small intestine, and the various glands associated with the alimentary canal such as salivary glands, the liver and the pancreas secrete digestive juices.

QUESTION: 5

Which of the following are examples of a symbiotic relationship?

1. Algae and fungus

2. Algae and bacteria

3. Fungus and bacteria

4. Plants and bacteria

Use the code given below to select the correct answer —

Solution:
  • There is a symbiotic relationship between algae and fungus. For example, in organisms called lichens, a chlorophyll-containing partner, which is an alga, and a fungus live together.

  • The fungus provides shelter, water and minerals to the alga and, in return, the alga prepares and provides food to the fungus. The bacterium called Rhizobium can take atmospheric nitrogen and convert it into a usable form.

  • But Rhizobium cannot make its own food. So, it often lives in the roots of gram, peas, moong, beans and other legumes and provides them with nitrogen. In return, the plants provide food and shelter to the bacteria. They, thus, have a symbiotic relationship. (i.e., between plants and bacteria).

QUESTION: 6

Consider the following statements :

1. Some organisms live together and share both shelter and nutrients. This relationship is called symbiosis.

2. Nutrition in which organisms take in nutrients from dead and decaying matter is called saprotrophic nutrition.

Which of the above statements/are true?

Solution:
  • Some organisms live together and share both shelter and nutrients. This relationship is called symbiosis. For example, certain fungi live inside the roots of plants.

  • The plants provide nutrients to the fungus and, in return, the fungus provides water and certain nutrients.

  • For example: lichens. The mode of nutrition in which organisms take in nutrients from dead and decaying matter is called saprotrophic nutrition. Such organisms with saprotrophic mode of nutrition are called saprotrophs.

  • For example fungi, that grow on pickles, leather, clothes and other articles that had been left out in hot and humid weather for a long time, is a saprotroph. Note that during the rainy season such fungal growth may spoil a lot of household things.

QUESTION: 7

Regarding plants, consider the following sentences:

1. All plants synthesize their food themselves.

2. Plants obtain nitrogen through roots present in the soil.

Which of the above assertions is/are correct?

Solution:
  • There are some plants which do not have chlorophyll. They cannot synthesise food. Like humans and animals such plants depend on the food produced by other plants. They use the heterotrophic mode of nutrition.

  • For example: Cuscuta (Amarbel). Plants cannot absorb nitrogen in gaseous form. Soil has certain bacteria that convert gaseous nitrogen into a usable form and release it into the soil. This is absorbed by the plants along with water.

QUESTION: 8

Consider the following assertions in relation to photosynthesis:

1. Only oxygen is formed from the process of photosynthesis.

2. In addition to the leaves, the other green parts of plants also carry out photosynthesis.

Which of the above assertions is/are correct?

Solution:
  • Both carbohydrate and oxygen are formed in the process of photosynthesis.Besides leaves, photosynthesis also takes place in other green parts of the plant - in green stems and green branches.

  • Desert plants have scales or spine-like leaves to reduce loss of water by transpiration. These plants have green stems which carry out photosynthesis.

QUESTION: 9

Which of the following is/are necessary for photosynthesis?

1. Chlorophyll

2. Sunlight

3. Carbon dioxide

4. Water

Use the code given below to select the correct answer —

Solution:
  • Leaves have a green pigment called chlorophyll. It helps leaves to capture the energy of sunlight. This energy is used to synthesise (prepare) food from carbon dioxide and water.

  • Since the synthesis of food occurs in the presence of sunlight, it is called photosynthesis (Photo: light; synthesis: to prepare). So, chlorophyll, sunlight, carbon dioxide and water are necessary to carry out the process of photosynthesis. What is photosynthesis?\

  • Photosynthesis is the process in which light energy is converted to chemical energy in the form of sugars. In a process driven by light energy, glucose molecules (or other sugars) are constructed from water and carbon dioxide, and oxygen is released as a byproduct. The glucose molecules provide organisms with two crucial resources: energy and fixed—organic—carbon.

QUESTION: 10

Which of the following is/are called 'Food Factories of Plants'?

1. Leaf

2. Stem

3. Root

4. Branch

Use the code given below to select the correct answer :

Solution:
  • Leaves are the food factories of plants. Water and minerals present in the soil are absorbed by the roots and transported to the leaves.

  • Therefore, all the raw materials must reach the leaf. A plant needs sunlight, carbon dioxide, minerals and water to make food by photosynthesis. A green substance in plants called chlorophyll traps the energy from the sun needed to make food. Chlorophyll is mostly found in leaves, inside plastids.

  • Which are inside the leaf cells. The leaf can be thought of as a food factory. Leaves of plants vary in shape and size, but they are always the plant organ best suited to capture solar energy. Once the food is made in the leaf, it is transported to the other parts of the plant such as stems and roots.

QUESTION: 11

Consider the following assertions

1. Fibers obtained from animals are known as fleece.

2. Silk fibers come from cocoons of the silk moth.

3. Sheep, goat and yak are wool-yielding animals.

Which of the above assertions is/are correct?

Solution: Wool is obtained from the fleece (hair) of sheep or yak. Silk fibres come from cocoons of the silk moth. Wool-yielding animals; for example (sheep, goat and yak) bear hair on their body.

QUESTION: 12

Which of the following assertions is/are incorrect?

1. Angora wool is obtained from Angora goats.

2. Angora goats are found in the hilly regions of Jammu and Kashmir.

3. Pashmina shawls are made from the soft under fur of Angora goats.

Use the code given below to select the correct answer —

Solution:
  • Angora wool or Angora fiber refers to the downy coat produced by the Angora rabbit. While their names are similar, Angora fiber is distinct from mohair, which comes from the Angora goat. Angora is known for its softness, low micron count (i.e. thin fibers), and what knitters refer to as a halo (fluffiness).

  • The name Pashmina has been derived from a Persian word “Pashm” meaning a weavable fiber precisely wool. The wool used for making Pashmina comes from a special breed of Kashmiri goat found in the high altitude regions of the Himalayas.

  • The 15th century ruler of Kashmir, Zaynul-Abidin, is said to be the founder of the wool industry in Kashmir. However, the history of these shawls can be traced back to the 3rd century BC.

  • Pashmina has been an integral part of traditional wear for centuries. In the earlier times, it was only worn by kings and queens and thus denoted royalty. The art of weaving Pashmina has been passed on as a legacy from generations to generations in the state of Kashmir. A good Pashmina shawl requires an expert hand for spinning, weaving and creating embroidery.

QUESTION: 13

Consider the following assertions in terms of silk

1. The rearing of silkworms for obtaining silk is called sericulture.

2. Silk fibers are made of proteins.

Which of the above assertions is/are correct?

Solution:
  • The rearing of silkworms for obtaining silk is called sericulture. The female silk moth lays hundreds of eggs, from which hatch larvae which are called caterpillars or silkworms.

  • They grow in size and when the caterpillar is ready to enter the next stage of its life history called pupa, it first weaves a net to hold itself.

  • Then it swings its head from side to side in the form of the figure of eight (8). During these movements of the head, the caterpillar secretes fibre made of a protein which hardens on exposure to air and becomes silk fibre.

QUESTION: 14

In relation to silk, which of the following assertions is/are correct?

1. The silk fibre is as strong as steel wire.

2. Tussar silk, muga silk and kosa silk are different varieties of silk.

Use the code given below to select the correct answer —

Solution:
  • The silk fibre is as strong as steel wire.There is a variety of silk moths which look very different from one another and the silk yarn they yield is different in texture (coarse, smooth, shiny, etc.).

  • Thus, tussar silk, muga silk, kosa silk, etc., are obtained from cocoons spun by different types of moths. The most common silk moth is the mulberry silk moth.

QUESTION: 15

Which of the following is not a measurement of temperature?

Solution: Pascal is the SI unit of Pressure whereas Celsius, Fahrenheit and Kelvin are the scales used in thermometers(a device used to measure temperature). The SI unit of temperature is Kelvin.