Problem 143 - Objective Biology for NEET

Question

The types of ribosome present in eukaryote cell is (a) \(70 \mathrm{~S}\) (b) \(80 \mathrm{~S}\) (c) Both (a) and (b) (d) None of these

Step-by-Step Solution

Answer

The correct answer is (b) \(80 \mathrm{~S}\).

Step 1: Identification of the type of ribosome

Understanding the question and the options provided, it can be seen that the exercise is asking for the ribosome's type in eukaryote cells. As known from cellular biology, in eukaryote cells, \(80 \mathrm{~S}\) ribosomes are present.

Key Concepts

Eukaryotic Cells

Eukaryotic cells are complex and highly organized structures, which can be found in both plant and animal life. Unlike prokaryotic cells, eukaryotes have a distinct nucleus enclosed within a membrane. This gives them a compartmentalized structure, with various organelles performing specific functions.
Key characteristics of eukaryotic cells include:

• The presence of membrane-bound organelles such as mitochondria, endoplasmic reticulum, and Golgi apparatus.
• A characteristic complex cytoskeleton providing structure and support.
• The ability to reproduce sexually through mitosis and meiosis.

Understanding eukaryotic cells is crucial for grasping the broader topics of cellular biology and life sciences, as they are the building blocks of complex life forms on Earth.

80S Ribosomes

In eukaryotic cells, 80S ribosomes are responsible for protein synthesis. They are larger and more complex than those found in prokaryotic cells. The 'S' stands for Svedberg units, a measure of sedimentation rate during centrifugation, which indicates the size and density of the ribosome.
Features of 80S ribosomes include:

• Subunits: Comprising a large (60S) and a small (40S) subunit.
• Function: Translating mRNA into polypeptide chains to form proteins crucial for cell function and structure.
• Location: Found either floating freely in the cytoplasm or attached to the rough endoplasmic reticulum (ER), indicating proteins destined for membranes or secretory pathways.

Knowing the function and structure of 80S ribosomes helps understand how cells produce the proteins vital for their survival and functionality.

Cellular Biology

Cellular biology is the study of cells, their physiological properties, structure, organelles, and interactions with their environment. It provides essential insights into how life operates at a molecular level.
The principles of cellular biology include:

• Understanding how cells harness energy to maintain life's functions.
• Exploration of cellular processes like signal transduction and osmoregulation.
• Studying cell replication processes, including mitosis and meiosis.

The insights gained from cellular biology form the foundation for medical and biotechnological advancements. It also helps elucidate how organisms grow, reproduce, and respond to their environments, providing a crucial understanding of biology.