8 Most VSAQ’s of The Unit of Life Chapter in Inter 1st Year Botany (TS/AP)

2 Marks

VSAQ-1 : What is the significance of vacuole in a plant cell?

  1. Osmotic Regulation: Vacuoles help maintain water balance within the cell, regulating turgor pressure and cell shape. By storing or releasing water and solutes, they prevent wilting or bursting of the cell.
  2. Storage: Vacuoles serve as storage compartments for various substances, including pigments, nutrients, and waste products. This storage function is essential for the plant’s metabolic processes and adaptation to changing environmental conditions.
  3. Detoxification: Vacuoles can store harmful substances, thereby protecting the rest of the cell from toxic compounds. This detoxification role is crucial for the plant’s survival.
  4. Structural Support: Vacuoles help maintain cell pressure, contributing to the structural support of the plant. They exert pressure against the cell wall, aiding in the rigidity and stability of plant tissues.
  5. Digestion: Some vacuoles contain enzymes responsible for breaking down waste materials and foreign substances. This digestive function plays a role in nutrient recycling and defense against pathogens.

VSAQ-2 : Mention a single membrane bound organelle which is rich in hydrolytic enzymes.

Lysosomes are the single membrane-bound organelles rich in hydrolytic enzymes. These enzymes are responsible for breaking down cellular waste materials, foreign substances, and cellular components, aiding in digestion and cellular maintenance.

VSAQ-3 : What does ‘S’ refer in a 70S and 80S ribosome?

The ‘S’ in 70S and 80S ribosomes stands for sedimentation coefficient, measured in Svedberg units (S). This coefficient indirectly indicates the density and size of the ribosome. It reflects the rate at which the ribosome sediments (settles) when subjected to centrifugation, with larger and denser structures having higher S values. In summary, the ‘S’ in ribosome terminology provides information about the ribosome’s size and density relative to sedimentation during centrifugation.

VSAQ-4 : What is the feature of a metacentric chromosome?

A metacentric chromosome is characterized by having its centromere located at the middle of the chromosome, creating two equal arms of the chromosome. This centromere placement results in symmetrical chromosome arms of approximately equal length on either side of the centromere.

VSAQ-5 : What is referred to as satellite chromosome?

A satellite chromosome is a chromosome that possesses a distinctive feature known as a satellite, which is a small segment separated from the main body of the chromosome by a secondary constriction. This secondary constriction often contains important genetic material and is involved in various genetic and cytological studies.

VSAQ-6 : What are microbodies? What do they certain?

  1. Peroxisomes:
    • Peroxisomes are involved in various metabolic processes, including the breakdown of fatty acids into phospholipids and the detoxification of harmful substances within the cell.
    • They also play a role in photorespiration in plant cells, helping to mitigate the effects of oxygen in photosynthesis.
  2. Glyoxysomes:
    • Glyoxysomes are specialized microbodies primarily found in plant cells, particularly in germinating seeds.
    • They contain enzymes that are essential for the glyoxylate cycle, a metabolic pathway allowing the conversion of stored lipids (fats) into carbohydrates.
    • This conversion is crucial for providing energy and carbon compounds during the early stages of seed germination, allowing the young plant to establish itself until it can perform photosynthesis.

VSAQ-7 : What is middle lamella made of? What is its functional significance?

The middle lamella is primarily composed of calcium pectate, which is a type of pectin.

Functional Significance:

  1. The middle lamella serves as a cementing material that holds neighboring plant cells together, especially in plant tissues where cell walls are in close contact.
  2. It plays a crucial role in cell adhesion by binding adjacent cell walls tightly, forming the primary cell wall.
  3. By providing structural support and cohesion to plant tissues, the middle lamella contributes to the integrity and strength of plant structures.
  4. Additionally, the presence of calcium pectate in the middle lamella contributes to the rigidity and stability of cell walls, which is vital for plant growth and development.

VSAQ-8 : Which part of the bacterial cell is targeted in gram staining?

In gram staining, the cell envelope of bacterial cells is the primary target. The bacterial cell envelope consists of the cell wall, cell membrane, and, in the case of gram-negative bacteria, the outer membrane. These components collectively make up the cell envelope, and the differences in their chemical composition between gram-positive and gram-negative bacteria lead to the differential staining characteristics observed in the gram staining technique. This differential staining helps distinguish between these two major categories of bacteria when viewed under a microscope.