Class 9 Science Chapter 5 MCQ Online Tests for 2021-2022
| Class: 9 | Science |
| Chapter: 5 | The Fundamental Unit of Life |
| Contents: | MCQ Online Tests with Answers |
Class 9 Science Chapter 5 MCQ with Answers for 2021-22
Class 9 Science Chapter 5 MCQ Online Test contains about 75 questions in all with answers and explanation. New questions will be added time to time to increase the question bank. All the questions are taken from NCERT Books for 9th Standard Science issued for academic session 2021-2022.
Q1
1 μ m is:
[A]. 10^–6 m
[B]. 10^–9 m
[C]. 10^–10 m
[D]. 10^–3 m
Answer: Option A
Explanation:The micrometer commonly known as micron in SI derived unit of length equaling to 10^-6 of a metre.
Q2
Organelle without a cell membrane is
[A]. Ribosome
[B]. Golgi apparatus
[C]. Chloroplast
[D]. Nucleus
Answer: Option A
Explanation:Nucleus is surrounded by two nuclear membranes was both forming a nuclear envelope. Golgi apparatus is a set of membrane bounded, fluid-filled visicles, vacuoles and flattened cisternae. Plastids are also membrane bound organelles but ribosomes moves freely in the matrix or remain attached to the endoplasmic reticulum.
Q3
In the last year board examination, Rahul were asked a question where he had to choose the statement which was/were correct? Will you be able to answer this question?
[A]. The chromatin material is a thin, thread like intertwined mass of chromosome material and composed of the genetic substance DNA and proteins.
[B]. DNA store all the information necessary for the cell to functions to grow and to reproduce further cells of the next generation.
[C]. Chromosomes are thread like structures usually present in the nucleus that become visible only during cell division.
[D]. All the above.
Answer: Option D
Explanation:Here, are all the statements are correct. Hence, your answer will be option [D].
Q4
In a quiz competition, you are asked a question where you have to choose the statement which is/ are incorrect?
[A]. Nuclear envelope encloses a space between two nuclear membranes and is connected to a system of membranes called the endoplasmic reticulum.
[B] Nucleus is rich in protein and RNA molecules and act as the site for ribosome formation.
[C] When a living plant cell loses water through osmosis, there is a shrinkage or contraction of the protoplasm away from the cell wall, called plasmolysis.
[D] None of the above.
Answer: Option D
Explanation:Here, are all the statements are correct. Hence, your answer will be option [D].
Q5
Cell wall of which one of these is not made up of cellulose?
[A]. Bacteria
[B]. Hydrilla
[C]. Mango tree
[D]. Cactus
Answer: Option A
Explanation: Plant cells, in addition to the plasma membrane, have another rigid rotor covering called the cell wall. The cell wall lies outside the plasma membrane. The plant cell wall is mainly composed of cellulose. Cellulose is a complex substance and provides structural strength to plants. Bacteria is not a plant therefore its cell wall is made up of “Peptidoglycan”.
Q6
Which out of the following is not a function of vacuole?
[A]. Storage
[B]. Providing turgidity and rigidity to the cell
[C]. Waste excretion
[D]. Locomotion
Answer: Option B
Explanation:Vacuoles may be small or large. These are filled with liquid or sap and are membrane-bound organelles. In animal cells, vacuoles are smaller in size and lesser in number than in plant cells. In some plant cells, only one large vacuole is present. The major portion of a plant cell is occupied by vacuoles.
The (approx. 90% in some cases) either may be contractile (can contract) or non-contractile. When the pressure of the contents of a contractile vacuole increases, it contracts and releases its contents. In unicellular organisms like Amoeba, food particles are present inside food vacuoles. But are not associated with locomotion.
The main functions of vacuoles are
1.In animals, vacuoles are often associated with the maintenance of water balance.
2.They work in osmoregulation, i.e., the maintenance of internal pressure.
3.They store various substances including waste products.
Q7
Pooja is completed her science chapter where she wrote some statements. She wants to know whether the statements are correct or not? She wants to take help from you:
[A]. Human heart has a special type of muscle cell called cardiac muscles.
[B]. Stomach has a special cell such as mucous cells.
[C]. Skeletal muscles are voluntary muscles i.e. their contraction depends on our will or control.
[D]. All the above.
Answer: Option D
Explanation: Here, are all the statements are correct. Hence, your answer will be option [D].
Q8
Abdul appeared in class test but he confused to know the incorrect statement. Would you help him to know that?
[A]. In human body, each cell has got certain specific components within it known as cell organelles.
[B]. Fixed shape of cell occurs in most plants and animals including Euglena and Paramecium.
[C]. In unicellular organisms the cell shape is maintained by tough plasma membrane and exoskeleton.
[D]. In nucleoid, its DNA content is equal to two or several DNA molecules.
Answer: Option D
Explanation: In nucleoid, its DNA content is equal to a single DNA molecule. Generally, in nucleus, its DNA content is equal to two or several DNA molecules.
Q9
Which of these is not related to endoplasmic reticulum?
[A]. It behaves as transport channel for proteins between nucleus and cytoplasm
[B]. It transports materials between various regions in cytoplasm
[C]. It can be the site of energy generation
[D]. It can be the site for some biochemical activities of the cell
Answer: Option C
Explanation:Endoplasmic reticulum exists as a membranous network, which is connected to the outer membrane of nucleus from one side and plasma membrane to the other.
It occurs in three forms
(i)Cisternae-closed fluid filled sac
(ii)Vesicles
(iii)Tubules
It is of two types, smooth endoplasmic reticulum i.e., without ribosomes on its surface and rough endoplasmic reticulum with ribosomes on its surface.
Q10
Which of these options are not a function of Ribosomes?
[A]. It helps in manufacture of protein molecules, and It helps in manufacture of enzymes.
[B]. It helps in manufacture of enzymes, and It helps in manufacture of hormones.
[C]. It helps in manufacture of hormones, and It helps in manufacture of starch molecules.
[D]. It helps in manufacture of starch molecules, and It helps in manufacture of protein molecules.
Answer: Option C
Explanation:Ribosomes are dense, spherical and granular particles which remains freely in the matrix or remain attached to endoplasmic reticulum. They are not bound by membrane and are present in both prokaryotic and eukaryotic cells. They play important role in synthesis of proteins. All enzymes are proteins but all hormones are not proteins.
What do understand by Hypertonic solution?
If the medium has a lower concentration of water than the cell, meaning that it is a very concentrated solution, the cell will lose water by osmosis. Such a solution is known as a hypertonic solution.
What is Plasmolysis?
When a living plant cell loses water through osmosis there is shrinkage or contraction of the contents of the cell away from the cell wall. This phenomenon is known as plasmolysis.
Why are Lysosomes known as suicide bags?
During the disturbance in cellular metabolism, for example, when the cell gets damaged, lysosomes may burst and the enzymes digest their own cell. Therefore, lysosomes are also known as the ‘suicide bags’ of a cell.
How does Mitochondria make their own protein?
Mitochondria have their own DNA and ribosomes. Therefore, mitochondria are able to make some of their own proteins.
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