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
Which of the following statement is or are incorrect about the growing crops inside green-houses?
[A]. A Greenhouse is built of any material through which sunlight can’t pass.
[B]. The air continues to heat up because it gets confined within the greenhouse.
[C]. To provide warmer temperature for growing fruit and vegetable plants.
[D]. Green-house also protect it from high blowing wind and rodents.
Answer: Option A
Explanation:A greenhouse is built of any material through which light can pass, such as glass or plastic. Farmers get many advantages like the crops grow well.
Q3
Which of the following statements is or are correct?
[A]. Insectivorous plants do not perform photosynthesis at all and they obtain nutrients from insects.
[B]. Parasitic nutrition is a type of “Heterotrophic Nutrition”.
[C]. The association of pulses plant with rhizobium bacteria is example of saprotrophic relationship.
[D]. None of the above.
Answer: Option B
Explanation:The mode of nutrition is which organisms depend on other for their food is called heterotrophic nutrition. An organism that takes their food or nutrient from others, without giving anything in return, called “parasitic nutrition”. And the body in which he lives is called a “host” and they take nutrients from the body of host and gradually parasite harms them and possible causing death.
Q4
In the absence of which of the following will photosynthesis not occur in leaves?
[A]. Guard cells
[B]. Chlorophyll
[C]. Vacuole
[D]. Space between cells
Answer: Option B
Explanation:Chlorophyll makes plants green. Chlorophyll is located in a plant’s chloroplasts, which are tiny structures in a plant’s cells. It is basically a group of green pigments used by organisms that convert sunlight into energy via photosynthesis. Without this energy, plants would be unable to initiate the process of photosynthesis, which converts water and carbon dioxide into starches that plants can use for food.
Q5
Pitcher plant traps insects because it
[A]. Is a heterotroph
[B]. Grows in soils which lack in nitrogen
[C]. Does not have chlorophyll
[D]. Has a digestive system like human beings
Answer: Option B
Explanation:Pitcher plant is an insectivorous plant that grow only in soils which do not contain sufficient nitrogen. These plants trap insects by various methods, kill them and digest then to obtain nitrogen compounds for their growth.
Q6
Paheli wants to know that some plants have deep red, violet or brown colored leaves but can these leaves perform the process of photosynthesis?
[A]. Yes, because they have different coloured as they trapped more solar energy.
[B]. No, because green pigment is not present in different coloured pigment.
[C]. Yes, because chlorophyll is hiding with leaf colour.
[D]. No, because they get nutrients from the soil and different colour attracts many organisms.
Answer: Option C
Explanation:Yes, because the chlorophyll needed for photosynthesis is hiding within the leaf colour. Plant leaves contain chlorophyll as “Carotenoids” and “Anthocyanins”. These assist chlorophyll in the process of 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
Photosynthesis requires chlorophyll and a few other raw materials as
[A]. H2O
[B]. Solar energy
[C]. CO2
[D]. All the above
Answer: Option D
Explanation:Photosynthesis is a process by which green plants make their own food from CO2 and H2O by using solar energy in the presence of chlorophyll. During the process oxygen is released.
Q9
Why insectivorous plants trap insects?
[A]. They can’t get sufficient nutrients, as nitrogen, from soil.
[B]. They want to take sometimes different nutrition as juices of insects.
[C]. They are autotrophs and some autotrophs are not able to make food.
[D]. Once in a week, they used their digestive system.
Answer: Option A
Explanation:Insectivorous plant are green and can-do photosynthesis. So, they are called autotrophs. But they can’t get sufficient nutrients from soil so, they trap insects and digest them. Due to this, they are called “partial heterotrophs”.
Q10
Choose the incorrect statements, what happened when wheat dough left in the open, after a few days
[A]. It starts to emit a foul smell.
[B]. It starts growth of saprophytic fungi and yeast.
[C]. Carbohydrate in wheat breakdown into carbon dioxide.
[D]. It is the place where rhizobium bacteria grow.
Answer: Option D
Explanation:Carbohydrate in wheat to encourage the growth of yeast and other saprophytic fungi. They breakdown carbohydrates into simpler compounds like carbon dioxide and alcohol that leads to a foul smell.
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.
