Class 9 Practice Level 3 – Set 1 - The Fundamental Unit of Life

Total questions: 15

Which of the following statements best explains the fluid mosaic model of the cell membrane?

Topic: Cell Membrane Dynamics

The cell membrane is a rigid structure composed of proteins and lipids.

The cell membrane is composed of a lipid bilayer with embedded proteins that can move laterally.

The cell membrane contains a static arrangement of carbohydrates and lipids.

The cell membrane is impermeable to all substances.

None

Which of the following is not a product of the light-dependent reactions of photosynthesis?

Topic: Photosynthesis

ATP

NADPH

Oxygen

Glucose

None

Which enzyme is responsible for unwinding the DNA helix during replication?

Topic: Nucleic Acids

DNA polymerase

Helicase

Ligase

Primase

None

During translation, the codon AUG codes for which amino acid?

Topic: Protein Synthesis

Serine

Glycine

Methionine

Proline

None

Which stage of cellular respiration produces the most ATP?

Topic: Cellular Respiration

Glycolysis

Krebs cycle

Electron transport chain

Fermentation

None

Which molecule acts as a second messenger in many signal transduction pathways?

Topic: Signal Transduction Pathways

ATP

AMP

DNA

RNA

None

The G1 checkpoint in the cell cycle is primarily influenced by

Topic: Cell Cycle Control

The size of the cell

The availability of nutrients

DNA damage

All of the above

None

Which transport mechanism involves the movement of water molecules through a semi-permeable membrane?

Topic: Membrane Transport

Active transport

Facilitated diffusion

Osmosis

Endocytosis

None

Cellular differentiation is primarily regulated by:

Topic: Cellular Differentiation

Environmental factors

Genetic factors

Both a and b

None of the above

None

10.

Which of the following factors does not affect enzyme activity?

Topic: Enzyme Function

Temperature

Substrate concentration

Light intensity

None

11.

In which part of the mitochondria does the Krebs cycle occur?

Topic: Cellular Respiration

Outer membrane

Inner membrane

Matrix

Intermembrane space

None

12.

The sodium-potassium pump is an example of:

Topic: Cell Membrane

Passive transport

Facilitated diffusion

Active transport

Osmosis

None

13.

Which photosynthetic pigment is most directly involved in the conversion of light energy to chemical energy?

Topic: Photosynthetic Pigments

Chlorophyll a

Chlorophyll b

Carotenoids

Xanthophylls

None

14.

The genetic code is described as degenerate because:

Topic: Genetic Code

It has multiple codons for a single amino acid

It contains stop codons

It has start codons

universal

None

15.

Which molecule is the final electron acceptor in the electron transport chain?

Topic: Cellular Respiration

NAD+

FAD

Oxygen

Water

None

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Class 9 Practice Level 3 – Set 1 - The Fundamental Unit of Life

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