Class 9 Science Chapter 5 MCQ Online Tests for 2020-2021
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 2020-21
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 2020-2021.
Q1
Which of the following statement is or are correct?
[A]. The vacuolar membrane is typically a single unit member and is often associated with the maintenance of water balance or ingestion of nutrient material.
[B]. In plant cells, the vacuoles are large, distinct and permanent.
[C]. Peroxisomes are specialized for carrying out some oxidative reactions, such as detoxification or removal of toxic substances from the cell.
[D]. All the above.
Answer: Option D
Explanation:Here, are all the statements are correct. Hence, your answer will be option [D].
Q2
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.
Q3
The only cell organelle seen in prokaryotic cell is
[A]. Mitochondria
[B]. Ribosomes
[C]. Plastids
[D]. Lysosomes
Answer: Option B
Explanation:Unlike eukaryotic cell, a prokaryotic cell lacks membrane bound organelles like plastids, mitochondria and endoplasmic reticulum but smaller and randomly scattered ribosomes are seen.
Q4
Cell arises from pre-existing cell was stated by
[A]. Haeckel
[B]. Virchow
[C]. Hooke
[D]. Schleiden
Answer: Option B
Explanation:In 1938 Schleiden proposed the idea that plants consist of cells. Later in the year 1839, Schwann independently asserted that all animals and plants are made up of cells. This joint finding forms the basis of cell theory.
The cell theory was refined further in 1855, when R. Virchow presented the idea that all cells arise from pre-existing cell. His amorphism was (Omnis Cellula-e-Cellula).
Q5
Silver nitrate solution is used to study
[A]. Endoplasmic reticulum
[B]. Golgi apparatus
[C]. Nucleus
[D]. Mitochondria
Answer: Option D
Explanation:Camillo Golgi, discovered the revolutionary method of staining individual cell structures. This method is referred to as “Black reaction”. It uses weak solution of silver nitrate and is valuable in tracing the processes and most delicate ramifications of cells.
Q6
Read the following sentences carefully, and choose the correct one(s):
[A]. Plasma membrane permits the entry and exit of some material in the cells.
[B]. Some substances such as carbon dioxide, oxygen, water etc. can move across the plasma membrane through a process called diffusion.
[C]. Diffusion is the spontaneous movement of molecules from a region of high concentration to one of lower concentration, until uniform concentration is finally achieved.
[D]. All the above.
Answer: Option D
Explanation:Here, are all the statements are correct. Hence, your answer will be option [D].
Q7
Rahul is doing his homework which is given by his teacher. Would you help him to choose the incorrect sentences?
[A]. The prokaryotic cells usually range between 1 to 10 micrometers (μm).
[B]. The largest size of an elephant is due to the larger cells present in its body.
[C]. Amoeba proteus is biggest among the unicellular organisms.
[D]. The smallest cells are those of mycoplasma gallisepticum, an organism intermediate between virus and bacteria.
Answer: Option B
Explanation:The volume of a cell is fairly constant for a particular cell type and is dependent to the size of an organism.
For example, kidney or liver cells are approximately the same size in a bull, horse and mouse. The difference in the total mass of the organ or organisms dependent on the number, not on the volume of the cells.
The cells of an elephant are not necessarily larger than those of other tiny animals or plants. The large size of an element is due to the larger number of cells present in its body.
Q8
Find out the correct sentence
[A]. Enzymes packed in Lysosomes are made through RER (rough endoplasmic reticulum)
[B]. Rough endoplasmic reticulum and smooth endoplasmic reticulum produce lipid and protein respectively
[C]. Endoplasmic reticulum is related with the destruction of plasma membrane
[D]. Nucleoid is present inside the nucleoplasm of eukaryotic nucleus
Answer: Option A
Explanation:The undefined nuclear region is the cytoplasm of prokaryotic cells is called nucleoid. The prokaryotic cells consist of a single chromosome, which is direct content of the cytoplasm i.e., there is no nuclear membrane in a eukaryotic cell, the nuclear envelope separates the nucleus from the cytoplasm.
The nuclear envelope contains many pores (the nuclear pores) and encloses the liquid ground substance, the nucleoplasm. Within nucleoplasm two types of nuclear structures are embedded-the nucleolus and chromatin material.
The nucleolus may be one or more in number and is not bounded by any membrane. It is rich in protein and RNA (Ribonucleic Acid) molecules and acts as the site for ribosome formation, hence are also known as factory of ribosomes.
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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