Cell MCQ Quiz - Objective Question with Answer for Cell - Download Free PDF

The correct answer is Humans.

Key Points

• Cell walls are present in most prokaryotes (except mollicute bacteria), in algae, fungi, and eukaryotes including plants but are absent in animals.

Additional Information

Plant cells have a cell wall, chloroplasts and other specialized plastids, and a large central vacuole, whereas animal cells do not.

• All cells have a cell membrane, but not all cells have a cell wall.
• Cell walls are very rigid, which makes the cell harder to move.
• They can be made up of a variety of substances, so cell walls in plant cells are different from those found in bacterial cells.
• A cell wall is a fairly rigid layer surrounding a cell located outside of the plasma membrane that provides additional support and protection.

The correct answer is Cellulose.

• Plant cell walls are primarily made of cellulose.

Key Points

• Cellulose is the most abundant macromolecule on Earth.
  • Cellulose fibers are long, linear polymers of hundreds of glucose molecules.
  • These fibres aggregate into bundles of about 40, which are called microfibrils.

Additional Information

• Carbohydrates are the sugars, starches, and fibres found in fruits, grains, vegetables, and milk products.
  • A carbohydrate is a biomolecule consisting of carbon (C), hydrogen (H), and oxygen (O) atoms.
• Lipids are molecules that contain hydrocarbons and make up the building blocks of the structure and function of living cells.
  • A lipid is a biomolecule that is soluble in nonpolar solvents.
• A lipoprotein is a biochemical assembly whose primary function is to transport hydrophobic lipid also known as fat molecules in water, as in blood plasma or other extracellular fluids.
  • It consists of a Triglyceride and Cholesterol centre, surrounded by a phospholipid outer shell, with the hydrophilic portions oriented outward towards the surrounding water and lipophilic portions oriented inward toward the lipid centre.

Explanation: 

The smallest living organism with a cell wall belongs to Bacteria.

• The size of the cell ranges from 0.5 micrometres to 100 micrometres. 
• Mycoplasma gallicepticum, a parasitic bacterium is thought to be the smallest known organism with a size from 0.2 to 0.3 micrometre, capable of independent growth and reproduction.

In the human body, the nerve cell is the longest cell.

• Nerve cells are also called neurons that are found in the nervous system.
• They can be up to 3 feet long.

Additional Information

• Mycoplasma is known as the smallest living cell but it does not have a cell wall.
• These are the unicellular organisms that can survive without oxygen.

Explanation: 

The smallest living organism with a cell wall belongs to Bacteria.

• The size of the cell ranges from 0.5 micrometres to 100 micrometres. 
• Mycoplasma gallicepticum, a parasitic bacterium is thought to be the smallest known organism with a size from 0.2 to 0.3 micrometre, capable of independent growth and reproduction.

In the human body, the nerve cell is the longest cell.

• Nerve cells are also called neurons that are found in the nervous system.
• They can be up to 3 feet long.

Additional Information

• Mycoplasma is known as the smallest living cell but it does not have a cell wall.
• These are the unicellular organisms that can survive without oxygen.

The correct answer is Cells of a tissue have similar Structure.

Explanation:

Cells: The cell is the basic structural, functional, and biological unit of all known organisms.

• There are different shapes of the cells.
• The size and shape of the cells might be different in different organism.
• Some cells have a nucleus (Eukaryotic cells) while the other does not have a defined nucleus (prokaryotic cells).

Tissues:  A tissue is a group of similar cells performing a specific function. These tissues further made organs and later organ system

⇒ The correct option in the above statements are - cells of tissue have a similar Structure.

The correct answer is Protein synthesis.

Key Points

• Ribosomes are membranous granular structures present in the cytoplasm.
• They were first observed under an electron microscope as dense particles by George Palade in the year 1953.
• Ribosomes are the site for ''protein synthesis'' so they are also called the ''protein factory'' of the cell.
• There are two types of ribosomes

1. Eukaryotic ribosomes - 80s - occurs in the cytoplasm of eukaryotic cell
2. Prokaryotic ribosomes - 70s - occur in the cytoplasm as well as are associated with the cell membrane of prokaryotic cell.

• The subunits of the ribosomes are:
  • 80s ribosomes - are made of 60s and 40s subunits.
  • 70s ribosomes - are made of 50s and 30s subunits.

Important Points

• Composition of the structure of ribosome:
• They are composed of ribonucleic acid (RNA) and proteins

Additional Information

• Photosynthesis: It is the process by which green plants and some other organisms use sunlight to synthesize nutrients from carbon dioxide and water. In this process, plant the chlorophyll, carbon dioxide, water, sunlight, and release oxygen.
• Synthesis of Fatty acids occurs in the cytoplasm.

The correct answer is Both chloroplast and mitochondria

Concept:

Theory of endosymbiosis:-

• Symbiotic relationship, where one organism lives inside the other, is known as endosymbiosis. 
• The theory proposed that mitochondria and chloroplasts evolved from engulfed prokaryotes.
• A large anaerobic bacteria engulfed an aerobic prokaryote, which then formed an endosymbiotic relationship with the host, gradually developing into a mitochondrion.
• It is believed that chloroplasts originated from a cyanobacterial endosymbiont.

Explanation:

Similarities between Prokaryotic cells, Mitochondria, and Chloroplast:

• Mitochondria and chloroplast are of the same size as prokaryotic cells.
• Mitochondria and prokaryotic cells both have their own circular DNA.
• The ribosome of bacteria, mitochondria, and chloroplasts have a 70S type of ribosome.
• Divides by binary fission.

The correct answer is Cellulose.

• Plant cell walls are primarily made of cellulose.

Key Points

• Cellulose is the most abundant macromolecule on Earth.
  • Cellulose fibers are long, linear polymers of hundreds of glucose molecules.
  • These fibres aggregate into bundles of about 40, which are called microfibrils.

Additional Information

• Carbohydrates are the sugars, starches, and fibres found in fruits, grains, vegetables, and milk products.
  • A carbohydrate is a biomolecule consisting of carbon (C), hydrogen (H), and oxygen (O) atoms.
• Lipids are molecules that contain hydrocarbons and make up the building blocks of the structure and function of living cells.
  • A lipid is a biomolecule that is soluble in nonpolar solvents.
• A lipoprotein is a biochemical assembly whose primary function is to transport hydrophobic lipid also known as fat molecules in water, as in blood plasma or other extracellular fluids.
  • It consists of a Triglyceride and Cholesterol centre, surrounded by a phospholipid outer shell, with the hydrophilic portions oriented outward towards the surrounding water and lipophilic portions oriented inward toward the lipid centre.

Concept:

• The cell is the basic unit of life. Life arises from pre-existing cells. Cells grow and multiply to form a diversity of life forms, this process of growth and multiplication of cells is called Cell Division.
• Cell division is of three types:

1. Mitosis - Equational division, occurs in somatic (non-sex) cells
2. Meiosis - Reducttional division, occurs in sex cells
3. Amitosis - Direct type of division, occurs in prokaryotes

• Meiosis can be further divided into two stages - Meiosis I and Meiosis II

Explanation:

• Prophase I of Meiosis I has 5 sub-stages
• Leptotene, Zygotene, Pachytene, Diplotene, Diakinesis.
• The Zygotene stage is characterized by the pairing of homologous chromosomes called the ''Synapsis''
• The pairs of homologous chromosomes are called Bivalents.
• There develops a structure between the homologous chromosomes called the synaptonemal complex. It is a tripartite structure i.e. it is made up of 3 thick lines of DNA and protein.

Additional Information 

• Leptotene: During leptotene, the chromatin condenses to form the chromosomes. Chromosomes are the longest and thinnest in this stage.
• Pachytene: This stage is characterized by the occurrence of crossing over. Non-sister chromatids of the homologous chromosomes exchange their genetic parts. 
• Metaphase I: The first metaphase of meiosis characterized by the alignment of paired chromosomes along the center (metaphase plate) of a cell, which ensures that two complete copies of chromosomes are present in the resulting two daughter cells of meiosis I. 

The correct answer is Lysosome.

Key Points

• ​Lysosome:
  • Lysosomes are an important cell organelle found within eukaryotic animal cells.
  • Due to their peculiar function, they are also known as the “suicide bags” of the cell.
  • Lysosomes work as the waste-discarding structures of the cell by processing undesirable materials and degrading them, both from the exterior of the cell and waste constituents inside the cell.
  • But sometimes, the digestive enzymes may end up damaging the lysosomes themselves, and this can cause the cell to die.
  • This is termed autolysis, where “auto” means “self” and “lysis” means “the disintegration of the cell by the destruction of its cell membrane“

Additional Information

• Peroxisomes:
  • It is a microbody.
  • In-plant it helps in photorespiration.
  • In animals concerned with peroxide metabolism.
• Glyoxysomes: These are the special type of peroxisomes found in plants & some fungi.
• Polysome: Many ribosomes may associate with a single mRNA to form multiple copies of a polypeptide simultaneously.
  • Such strings of ribosomes are termed as Polysome.

The correct answer is Metaphase.

 Key Points

• Cell Division is the process by which a mature cell divides and forms 2 nearly equal daughter cells that resemble the parental cell in a number of characteristics.
• 2 processes take place during cell reproduction.
• Cell growth: which is the period of synthesis and duplication of various components of the cell.
• Cell division: It is the process when a mature cell divides into two cells.
• The Cell cycle completes in 2 steps: 

1. Interphase
2. M-phase/Dividing phase

 Additional Information

• The M-phase or Mitosis is further divided into 4 sub-stages:

1. Prophase 
2. Metaphase
3. Anaphase
4. Telophase

• Metaphase is characterized by:
• The complete disintegration of the nuclear envelope, hence the chromosomes are spread throughout the cytoplasm
• Completion of the condensation of chromosomes, so the chromosomes are clearly visible and their morphology is best studied.
• Spindle fibres formed and get attached to the chromosomes at the kinetochore disc.
• The chromosomes align themselves at the equator.

 Additional Information

The correct answer is Cellulose.

• The epidermis is the protective outer layer of clonally related cells covering all plant organs.
• It is made up of cellulose, hemicelluloses, and pectin.

Important Points

• Functions of the cell wall in the plant:
  • Regulates and controls the direction of cell growth.
  • Providing strength, structural support, and maintaining the shape of the cell.
  • It supports the entry of smaller molecules moving freely.

Additional Information

• Cell Membrane is present in all organisms including plants.
  • It is also known as the plasma membrane.
  • It is a semi-permeable membrane composed of lipids and proteins.

The correct answer is ,

Key Points

• Both mitochondria and chloroplasts possess their own genetic material thus, they are called semi-autonomous organelles.
• The mitochondrial DNA and plastid DNA possess genes that produce the proteins necessary for the functioning of mitochondria and chloroplasts respectively.

Important Points

• Mitochondria (sing.: mitochondrion), unless specifically stained, are not easily visible under the microscope.
• The number of mitochondria per cell is variable depending on the physiological activity of the cells.
• In terms of shape and size also, a considerable degree of variability is observed.
• Typically it is sausage-shaped or cylindrical having a diameter of 0.2-1.0µm (average 0.5µm) and length 1.0-4.1µm.
• Each mitochondrion is a double membrane-bound structure with the outer membrane and the inner membrane dividing its lumen distinctly into two aqueous compartments, i.e. the outer compartment and the inner compartment.

Concept:

• Cell Division is the process by which a mature cell divides and forms 2 nearly equal daughter cells which resemble the parental cell in a number of characteristics.
• 2 processes take place during cell reproduction.
• Cell growth: this is the period of synthesis and duplication of various components of the cell.
• Cell division: It is the process which a mature cell divides into two cells.
• The Cell cycle completes in 2 steps: 

1. Interphase
2. M-phase/Dividing phase

Explanation:

• Interphase is the period between the end of one cell division to the beginning of the next cell division.
• The interphase takes almost 95% of the total time of the cell cycle.
• During interphase, the cell prepares itself for the next division, and it grows in size. So the cell is the most active metabolically in Interphase.
• Interphase is divided into 3 phases:

1. G1 phase/Post mitotic/Pre-DNA synthetic phase/Ist gap phase
2. S-phase/Synthetic phase
3. G2-phase/Pre mitotic/Post synthetic phase/IInd gap phase.

Important Points

• Earlier Interphase was considered as the resting phase in the cell cycle, but recent studies have revealed that the cell is the most active in this phase as it prepares for the next division, so it cannot be called resting instead it is called the preparing phase.

Additional Information

•  M-phase/Dividing phase has four sub-phases: Prophase, Metaphase, Anaphase, Telophase

Key Points

Explanation:

• Ribosomes are known as protein factories because they are the main site of protein synthesis. The molecule of RNA which is a component of the ribosome organelle is called ribosomal RNA.
• Ribosomes are composed of ribonucleic acids and proteins.
• It is made up of two subunits-
  • Large subunits- join amino acids to form a polypeptide chain.
  • Small subunits- reads RNA.

So, each subunit is made up of one or more of ribosomal RNA and ribosomal proteins.