General Science Question Answers Chapter 10 Cell and Cell Organelles Class 8 Maharashtra Board

Question Answers For All Chapters – General Science Class 8

Exercise

1. Who am I?

(a) I am ATP producing factory. → Mitochondria

• Mitochondria are called the “powerhouse of the cell” because they produce ATP (energy) through respiration.

(b) I am single-layered but maintain cellular osmotic pressure. → Vacuole

• The vacuole is a fluid-filled sac that stores water, food, and waste. It helps maintain the osmotic balance inside the cell.

(c) I support the cell, but I am not a cell wall. I have a body resembling a net. → Endoplasmic Reticulum

• The endoplasmic reticulum (ER) is a network of membranes inside the cell that helps in the transport of materials and provides structural support.

(d) I am the chemical factory of the cell. → Golgi Complex

• The Golgi complex modifies, stores, and packages proteins and lipids to be sent to different parts of the cell.

(e) Leaves are green because of me. → Chloroplast

• Chloroplasts contain chlorophyll, which gives leaves their green color and helps in photosynthesis.

2. What would have happened if…?

(a) RBCs had mitochondria.

• RBCs transport oxygen to all body cells. If they had mitochondria, they would consume oxygen for their own energy instead of delivering it to tissues. This would make oxygen transport less efficient.

(b) There had been no difference between mitochondria and plastids.

• Mitochondria provide energy for animal and plant cells, while plastids are found only in plant cells for photosynthesis and storage. If they were the same, plants might not be able to make food, and animal cells might have unnecessary organelles.

(c) Genes had been absent on the chromosomes.

• Genes carry hereditary information from parents to offspring. Without genes, living organisms would not inherit traits, and evolution would not occur.

(d) Plasma membrane had not been selectively permeable.

• The plasma membrane controls what enters and leaves the cell. If it were not selectively permeable, harmful substances could enter freely, and important materials could leak out, damaging the cell.

(e) Plants lacked anthocyanin.

• Anthocyanin gives red, purple, and blue colors to flowers and fruits. Without it, plants would not have these colors, which would reduce pollination and affect fruit development.

3. Who is the odd one out? Give reason.

(a) Nucleolus, Mitochondria, Plastids, Endoplasmic Reticulum

• Nucleolus is the odd one out because it is inside the nucleus, while the others are found in the cytoplasm.

(b) DNA, Ribosomes, Chlorophyll

• Chlorophyll is the odd one out because it is a pigment found in plants, while DNA and ribosomes are involved in protein synthesis in all cells.

4. Give functions.

(a) Plasma Membrane

• The plasma membrane is a thin outer layer of the cell that protects it and controls the movement of substances in and out of the cell.

(b) Cytoplasm

• The cytoplasm is a jelly-like fluid inside the cell where all organelles are suspended. It also supports chemical reactions needed for life.

(c) Lysosome

• Lysosomes are called “suicide bags” because they digest waste materials and destroy damaged or harmful substances inside the cell.

(d) Vacuole

• Vacuoles store water, nutrients, and waste products. In plant cells, vacuoles help maintain turgor pressure, keeping the plant firm.

(e) Nucleus

• The nucleus is the control center of the cell, containing DNA that determines heredity and cell functions. It regulates growth, metabolism, and reproduction.

5. Who gives me the color? (Select the correct option.)