Class 7 Science Chapter 1 MCQ for 2020-21
Class: | 7 |
Subject: | Science |
Contents: | Multiple Choice Questions – MCQ Tests |
Class 7 Science Chapter 1 MCQ for Exams
Class 7 Science Chapter 1 MCQs are given below with answers and explanation of each answer. There are over 10 set of papers each containing 10 questions for practice. All the questions are prepared from NCERT textbook and exemplar books only. All the questions are confined to CBSE Syllabus 2020-21.
Q1
“Leaves are the food factories of plant”. But, how does cactus (desert plants) carry out photosynthesis?
[A]. Roots
[B]. Spines
[C]. Stems
[D]. Green leaves
Answer: Option C
Explanation:Photosynthesis also takes place in other green parts of the plant — in green stems and green branches. The desert plants have scale- or spine-like leaves to reduce loss of water by transpiration. These plants have green stems which carry out photosynthesis.
Q2
The cell is enclosed by a thin outer boundary, called
[A]. Cell membrane
[B]. Chromatin
[C]. Cytoplasm
[D]. Nucleus membrane
Answer: Option A
Explanation:The bodies of living organisms are made of tiny units called “cells”. Cells can be seen only under the microscope. Some organisms are made of only one cell. The cell is enclosed by a thin outer boundary, called the “cell membrane”.
Q3
The term that is used for the mode of nutrition in yeast, mushrooms and bread mould is: autotrophic insectivorous saprophytic parasitic
[A]. Autotrophic
[B]. Insectivorous
[C]. Saprophytic
[D]. Parasitic
Answer: Option C
Explanation:Saprophytic nutrition is scene in yeast, mushroom and bread mould. In this mode of nutrition, organisms obtain their food from dead and decaying organic matter. Such organisms are known as saprophytes.
Q4
The term that is used for the mode of nutrition in yeast, mushrooms and bread-mould is
[A]. Autotrophic
[B]. Insectivorous
[C]. Saprophytic
[D]. Parasitic
Answer: Option C
Explanation:These organisms (yeast, mushrooms and bread-mould) are called “fungi”. They have a different mode of nutrition. They secrete digestive juices on the dead and decaying matter and convert it into a solution. Then they absorb the nutrients from it. This mode of nutrition in which organisms take in nutrients in solution form from dead and decaying matter is called “saprotrophic nutrition”. Plants which use saprotrophic mode of nutrition are called “saprotrophs”.
Q5
About “photosynthesis”, which of the statements is or are incorrect?
[A]. The Solar Energy is captured by the leaves and stored in the form of food.
[B]. Later on carbohydrate ultimate get converted into chlorophyll.
[C]. The synthesis prepare of food occurs in the presence of only sunlight.
[D]. In this process solar energy is converted into chemical energy.
Answer: Option B
Explanation:Chlorophyll, sunlight, carbon dioxide and water are necessary to carry out the process of photosynthesis. During the process oxygen is released. The carbohydrates ultimately get converted into starch. The presence of starch in leaves indicates the occurrence of photosynthesis. The starch is also a carbohydrate.
Q6
Which of the following statement is or are correct?
[A]. All green plants can prepare their own food and oxygen is liberated during photosynthesis.
[B]. Most animals are autotrophs.
[C]. Most animals are autotrophs and carbon dioxide is not required for photosynthesis
[D]. All green plants can prepare their own food and most animal are autotrophs.
Answer: Option A
Explanation:Statement [A] is correct. All green plants are autotrophs. They can make their own food from simple substances like CO2 and H2O by the process of photosynthesis. Oxygen gas produced during this process is liberated into the air. The other statements in correct form are: Most animals are heterotrophs and CO2 is essential for photosynthesis.
Q7
Farmers do not apply nitrogenous fertilizers in the cultivation of pulses plant. Why?
[A]. Pulses plant already have stored much nitrogenous compound.
[B]. Pulses plant do not need the compound of nitrogen because they are autotrophs.
[C]. Pulses plant fulfill their needs by saprotrophic nutrition.
[D]. Pulses plant derive nutrition from the symbiotic association.
Answer: Option D
Explanation:Generally, leguminous plant such as gram, pulses. These plants have root nodules in them which have a symbiotic association with rhizobium bacteria. It converts nitrogen gases as compounds. In return, the plants provide food and shelter to the bacteria. Hence, farmers do not need to apply nitrogenous fertilizers in the field during cultivation.
Q8
Which of the following equations is correct about “photosynthesis”?
[A]. Carbon dioxide + Water + (Sunlight and Chlorophyll) → Carbohydrates + Ozone
[B]. Carbon dioxide + Hydrogen + (Sunlight and Chlorophyll) → Carbohydrates + Oxygen
[C]. Nitrogen dioxide + Water + (Sunlight and Chlorophyll) → Carbohydrates + Ozone
[D]. Carbon dioxide + Water + (Sunlight and Chlorophyll) → Carbohydrates + Oxygen
Answer: Option D
Explanation:Plants synthesise their food with the help of chlorophyll. It helps to capture the energy of Sunlight. Plants get raw materials form surroundings. So, we find that sunlight, chlorophyll, carbon dioxide and water are necessary components to carry out the process of photosynthesis. And carbohydrates produced and ultimately converted into starch. During this process oxygen is released which is very essential for the survival all living organisms.
Q9
What would happen, if a goat eats away all the leaves of a small plant
[A]. Plant will no more.
[B]. Remaining leaves and branches will help to sustain the plant.
[C]. The small plant survived on the food stored in the stem and roots.
[D]. Soil nutrients will help to survive the plant once again.
Answer: Option C
Explanation:When a goat eats all the leaves of a small plant. Still new leaves could be seen sprouting in the plant again. This is just because the small plant survived on the food stored in the stem and roots. It might have undergone gaseous exchange through lenticels on stem.
Q10
Algae and fungi are
[A]. Autotroph and Parasite
[B]. Heterotroph and Saprotroph
[C]. Heterotroph and Parasite
[D]. Autotroph and Saprotroph
Answer: Option D
Explanation:We see slimy, green patches in ponds or in other stagnant water bodies. These are generally formed by the growth of organisms called “algae”. They contain chlorophyll. Algae can also prepare their own food by photosynthesis, so they are known as “Autotrophs”. We have also seen fluffy patches of white, green, brown color growing on rotting wood during the rainy season. These organisms are called “fungi”. They take in nutrients in solution form from dead and decaying matter, called “Saprotrophs”.
Why do all living being need food?
All living organisms require food for cellular activities like growth, development and physical activities.
Who are Autotrophs?
Organisms which make their own food are called Autotrophs like plants.
What do you mean by Photosynthesis?
Photosynthesis is the process by which plants make their own food.
How do green plants prepare their food?
Green plants use water, carbon dioxide and sunlight to prepare their food by the process of photosynthesis.
Chlorophyll and Photosynthesis
When we see around us, we find that most of the plant leaves are green in colour. It is because leaf cells contain green pigments called Chlorophyll. The photosynthesis happens at this site of leaf’s cell. Chlorophyll helps in trapping of sun light energy. Water is absorbed by the root hairs from the soil and carbon dioxide coming from atmosphere is taken in through the stomata of leaf. Water and carbon dioxide combine in presence of sunlight trapped by chlorophyll and produces glucose and releases oxygen into the atmosphere. This complete process is called Photosynthesis.
Currently in Class test of standard 7 or school exams, MCQs are compulsory in each subject. These MCQs will help the students to understand the concepts given in Chapter 1 of Class 7 Science. Definitions, keywords and all extra questions are included in the form of multiple choice questions to provide a better practice for grade 7 student.