Class 12 Biology Quiz

Questions and Answers

What is the primary function of the cell membrane in a biological cell?

To store genetic information

To control the movement of substances in and out of the cell (correct)

To generate energy for the cell

To facilitate protein synthesis

Which process is responsible for the production of ATP in cellular respiration?

Lactic acid cycle

Electron transport chain (correct)

Glycolysis

Fermentation

How do enzymes affect chemical reactions in biological systems?

They increase the activation energy required

They serve as reactants in the reactions

They lower the activation energy, increasing the reaction rate (correct)

They slow down the reaction rate

Which statement describes homologous chromosomes?

<p>They are the same size but may carry different alleles</p> Signup and view all the answers

What role do ribosomes play in the cell?

<p>They are responsible for protein synthesis</p> Signup and view all the answers

Study Notes

Cell Membrane Function

Serves as a protective barrier, maintaining the integrity of the cell's internal environment.
Regulates the movement of substances in and out of the cell through selective permeability.
Facilitates communication and signaling with other cells through receptor proteins.

Cellular Respiration and ATP Production

ATP production primarily occurs through cellular respiration processes: glycolysis, the Krebs cycle, and oxidative phosphorylation.
Oxygen plays a crucial role in aerobic respiration, enhancing ATP yield compared to anaerobic processes.

Enzyme Function in Reactions

Enzymes are biological catalysts that speed up chemical reactions by lowering activation energy.
They increase reaction rates without being consumed or permanently altered in the process.
Enzyme activity can be affected by temperature, pH, and substrate concentration.

Homologous Chromosomes

Homologous chromosomes are pairs of chromosomes, one inherited from each parent, containing the same genes but possibly different alleles.
They maintain the same structural features and gene order, playing a key role in genetic diversity during meiosis.

Role of Ribosomes

Ribosomes are essential for protein synthesis, translating messenger RNA (mRNA) into polypeptide chains.
They can be found free-floating in the cytoplasm or attached to the endoplasmic reticulum, contributing to rough ER function.
Their presence is vital for cellular function and growth, enabling the production of necessary proteins.

Description

Test your knowledge on key concepts in biology with this quiz focused on the cell membrane, cellular respiration, enzymes, homologous chromosomes, and the role of ribosomes. Perfect for Class 12 students looking to reinforce their understanding of these fundamental topics.