Cell: The Unit of Life

Correct Answer: B

1. The cell is the basic unit of life.
2. All living organisms are composed of cells.
3. Some organisms are unicellular.
4. Others are multicellular.
5. Multicellular organisms have many cells.
6. These cells form tissues and organs.
7. Cells perform all life functions.
8. This is part of cell theory.
9. It applies to all living beings.
10. Thus, organisms are made of cells or aggregates of cells.

Correct Answer: B

1. Cells are the basic units of life.
2. Different cells perform different functions.
3. Their shape varies depending on function.
4. Their size also differs.
5. Some cells are large, others are small.
6. Activities/functions also vary.
7. Example: nerve cells and muscle cells.
8. This variation helps specialization.
9. It supports efficient functioning.
10. Thus, cells vary in shape, size and functions.

Correct Answer: C

1. Cells are classified based on nucleus presence.
2. Some cells have membrane bound nucleus.
3. These are called eukaryotic cells.
4. Some cells lack membrane bound nucleus.
5. These are called prokaryotic cells.
6. Organelles also differ between them.
7. This classification is fundamental.
8. It helps understand cell structure.
9. Applies to all organisms.
10. Thus, cells are eukaryotic or prokaryotic.

Correct Answer: B

1. Eukaryotic cells are complex cells.
2. They have a membrane bound nucleus.
3. The outer boundary is the cell membrane.
4. Inside is the cytoplasm.
5. The nucleus controls cell activities.
6. Cytoplasm contains organelles.
7. These three are main parts.
8. They are present in all eukaryotic cells.
9. This is the basic structure.
10. Thus, a eukaryotic cell has cell membrane, nucleus and cytoplasm.

Correct Answer: B

1. Plant cells have an extra outer layer.
2. This layer is present outside the cell membrane.
3. It is called the cell wall.
4. It provides strength and support.
5. It protects the cell.
6. It is mainly made of cellulose.
7. Animal cells do not have this structure.
8. It helps maintain shape.
9. It prevents bursting.
10. Thus, plant cells have a cell wall.

Correct Answer: C

1. The plasma membrane surrounds the cell.
2. It controls movement of substances.
3. Not all molecules can pass through it.
4. Only specific molecules are allowed.
5. This property is called selective permeability.
6. It helps maintain internal balance.
7. It allows transport of needed substances.
8. It prevents entry of harmful materials.
9. It is essential for cell survival.
10. Thus, plasma membrane is selectively permeable.

Correct Answer: B

1. The endomembrane system is a group of organelles.
2. These organelles work together.
3. It includes endoplasmic reticulum (ER).
4. It also includes Golgi complex.
5. Lysosomes are part of this system.
6. Vacuoles are also included.
7. They help in synthesis and transport.
8. They also help in storage and digestion.
9. These organelles are membrane bound.
10. Thus, ER, Golgi complex, lysosomes and vacuoles form the endomembrane system.

Correct Answer: B

1. Cells contain many organelles.
2. Each organelle has a unique role.
3. They do not perform the same function.
4. Example: mitochondria produce energy.
5. Ribosomes synthesize proteins.
6. Golgi apparatus modifies materials.
7. Lysosomes help in digestion.
8. This specialization increases efficiency.
9. All work together for cell survival.
10. Thus, organelles perform different but specific functions.

Correct Answer: B

1. Centrosome contains centrioles.
2. Centrioles are important structures.
3. They help in formation of cilia and flagella.
4. These structures help in movement.
5. The base of cilia and flagella is formed by centrioles.
6. This base is called basal body.
7. It anchors these structures.
8. It helps in locomotion.
9. Present mainly in animal cells.
10. Thus, centrioles form basal body.

Correct Answer: B

1. Centrioles are present in animal cells.
2. They play a role in cell division.
3. During division, they organize microtubules.
4. These microtubules form spindle fibres.
5. Together they make the spindle apparatus.
6. This helps in chromosome movement.
7. It ensures proper separation.
8. Essential for mitosis and meiosis.
9. Without it, division fails.
10. Thus, centrioles form spindle apparatus.

Correct Answer: B

1. The nucleus is an important cell organelle.
2. It controls cell activities.
3. Inside the nucleus is nucleoplasm.
4. It contains nucleoli.
5. Nucleoli help in ribosome formation.
6. It also contains chromatin network.
7. Chromatin has DNA and proteins.
8. It forms chromosomes during division.
9. These components are essential.
10. Thus, nucleus contains nucleoli and chromatin network.

Correct Answer: B

1. The nucleus is the control center of the cell.
2. It regulates activities of organelles.
3. It contains genetic material.
4. This material is DNA.
5. DNA carries hereditary information.
6. This information is passed to offspring.
7. Thus, nucleus controls activities and heredity.
8. It is essential for cell function.
9. It ensures continuity of life.
10. Thus, it controls organelle activities and heredity.

Correct Answer: B

1. Endoplasmic reticulum (ER) is a network.
2. It is present in the cytoplasm.
3. It forms a complex system.
4. It consists of tubules.
5. It also has flattened sacs called cisternae.
6. These structures help in transport.
7. ER is of two types: rough and smooth.
8. Rough ER has ribosomes.
9. Smooth ER lacks ribosomes.
10. Thus, ER contains tubules or cisternae.

Correct Answer: B

1. Endoplasmic reticulum is a cell organelle.
2. It is present in the cytoplasm.
3. It has a network structure.
4. It exists in two forms.
5. One type has ribosomes on its surface.
6. This is called rough ER.
7. The other type lacks ribosomes.
8. This is called smooth ER.
9. Both have different functions.
10. Thus, ER are of two types: rough and smooth.

Correct Answer: B

1. Endoplasmic reticulum is a network of membranes.
2. It helps in transport of substances.
3. Materials move within the cell through ER.
4. Rough ER helps in protein synthesis.
5. Smooth ER helps in lipid synthesis.
6. It also helps in lipoprotein formation.
7. Glycogen synthesis is also supported.
8. It plays multiple roles in the cell.
9. It connects different parts of the cell.
10. Thus, ER helps in transport and synthesis functions.

Correct Answer: B

1. Golgi body is a cell organelle.
2. It is membrane bound.
3. It consists of stacked structures.
4. These structures are flattened.
5. They are called sacs or cisternae.
6. It helps in modification of proteins.
7. It also helps in packaging.
8. Materials are transported from here.
9. It is important for secretion.
10. Thus, Golgi body has flattened sacs.

Correct Answer: B

1. Golgi body is a membranous organelle.
2. It modifies cell products.
3. It packages proteins and other materials.
4. These are called secretions.
5. Secretions are packed into vesicles.
6. These vesicles move to the cell membrane.
7. Materials are then transported outside the cell.
8. This process is called secretion.
9. Golgi plays a key role in this.
10. Thus, secretions are packed and transported by Golgi body.

Correct Answer: B

1. Lysosomes are cell organelles.
2. They are surrounded by a single membrane.
3. They contain digestive enzymes.
4. These enzymes break down macromolecules.
5. Macromolecules include proteins, lipids and carbohydrates.
6. Lysosomes help in intracellular digestion.
7. They remove waste materials.
8. They are called suicidal bags.
9. Important for cell maintenance.
10. Thus, lysosomes are single membrane structures with enzymes.

Correct Answer: B

1. Ribosomes are small organelles.
2. They are present in cytoplasm.
3. They may be free or attached to ER.
4. They help in making proteins.
5. They read mRNA information.
6. Amino acids are joined together.
7. This forms proteins.
8. Proteins are essential for cells.
9. Ribosomes are called protein factories.
10. Thus, ribosomes are involved in protein synthesis.

Correct Answer: B

1. Ribosomes are small organelles.
2. They are present in cells.
3. Some ribosomes are free in cytoplasm.
4. These synthesize proteins for internal use.
5. Some are attached to endoplasmic reticulum.
6. This forms rough ER.
7. These synthesize secretory proteins.
8. Both types are important.
9. They help in protein production.
10. Thus, ribosomes occur freely or on ER.

Correct Answer: B

1. Mitochondria are known as powerhouse of the cell.
2. They are involved in energy production.
3. They perform oxidative phosphorylation.
4. This process generates ATP.
5. ATP stands for adenosine triphosphate.
6. It is the energy currency of the cell.
7. This energy is used for various activities.
8. Mitochondria are essential for respiration.
9. They are found in eukaryotic cells.
10. Thus, mitochondria produce ATP through oxidative phosphorylation.

Correct Answer: B

1. Mitochondria are cell organelles.
2. They are surrounded by two membranes.
3. This is called double membrane.
4. The outer membrane is smooth.
5. The inner membrane is folded.
6. These folds are called cristae.
7. Cristae increase surface area.
8. They help in energy production.
9. This structure is important for function.
10. Thus, mitochondria have double membrane with cristae.

Correct Answer: B

1. Plastids are cell organelles.
2. They contain pigments.
3. These pigments give color.
4. Plastids are found only in plant cells.
5. They are absent in animal cells.
6. Types include chloroplast, chromoplast, leucoplast.
7. Chloroplast helps in photosynthesis.
8. They are important for plants.
9. They store food and pigments.
10. Thus, plastids are found in plant cells.

Correct Answer: B

1. Chloroplasts are present in plant cells.
2. They contain chlorophyll pigment.
3. Chlorophyll absorbs light energy.
4. This energy is used in photosynthesis.
5. Photosynthesis produces food.
6. It converts light energy into chemical energy.
7. Chloroplasts are essential for this process.
8. They are absent in animal cells.
9. They give green color to plants.
10. Thus, chloroplasts trap light energy.

Correct Answer: B

1. Plastids include chloroplasts.
2. Inside chloroplast, grana are present.
3. Grana are stacks of thylakoids.
4. Light reactions occur in grana.
5. These reactions use light energy.
6. Stroma is the fluid part.
7. Dark reactions occur in stroma.
8. These reactions form glucose.
9. Both processes are essential.
10. Thus, grana are sites of light reactions.

Correct Answer: B

1. Plastids are present in plant cells.
2. Chloroplasts are green coloured plastids.
3. They contain chlorophyll pigment.
4. Chlorophyll helps in photosynthesis.
5. Chromoplasts are other coloured plastids.
6. They contain different pigments.
7. These include carotene and xanthophyll.
8. These pigments give yellow, orange colors.
9. They are important for plant coloration.
10. Thus, chloroplasts have chlorophyll and chromoplasts have carotene and xanthophyll.

Correct Answer: B

1. The nucleus is an important organelle.
2. It is surrounded by a boundary.
3. This boundary is called nuclear envelope.
4. It has two membranes.
5. Hence, it is a double membrane structure.
6. It contains openings.
7. These openings are nuclear pores.
8. They allow exchange of materials.
9. Between nucleus and cytoplasm.
10. Thus, nucleus has nuclear envelope with pores.

Correct Answer: B

1. The nucleus has a double membrane.
2. The inner membrane surrounds internal contents.
3. Inside is the nucleoplasm.
4. It also contains chromatin material.
5. Chromatin has DNA and proteins.
6. These are essential for genetic functions.
7. The inner membrane encloses them.
8. It separates nucleus from cytoplasm.
9. Maintains organization.
10. Thus, inner membrane encloses nucleoplasm and chromatin.

Correct Answer: B

1. Cells are the basic units of life.
2. All organisms are made of cells.
3. Cells provide structure to the body.
4. They also perform various functions.
5. All life processes occur in cells.
6. This includes metabolism and growth.
7. Cells help in reproduction.
8. They maintain life activities.
9. Hence, they are both structural and functional units.
10. Thus, cell is the structural and functional unit of life.