The Fundamental Unit of Life Test - 28

Vacuoles are the membranous inclusions that store water which is further conducted by conducting tissues to other parts of the plant. It also helps in osmoregulation. It is centrally placed in the plant cell while it is pushed towards the periphery in the animal cell. It also stores air and food.

Lysosomes are membrane-bound cellular organelles. They possess many enzymes for the intracellular digestion of waste, dead organelles, debris, as engulfed, killed viruses or bacteria.

Lysosomes are the smallest vesicle-like cell organelles, surrounded by a single membrane. It consists hydrolytic enzymes which break down the foreign particles, dead cellular content, etc. The lysosomal membrane allows the digestive enzymes to work at lower pH.

So, the correct answer is option A.

The material which is mounted on the slide is usually of fluid consistency. So, to avoid its spilling from sides, it is mounted in the centre. Also, if it is mounted at left or right side, then under microscope the material is not seen clearly. Hence, usually material is mounted in the centre. 

In the hypertonic solution, the concentration of solutes is more and the concentration of solvent (water) is less as compared to the cytoplasm of a specific cell. If a cell is placed in such a solution plasmolysis will occur due to the movement of water from the cell to the outer environment.

• The nucleus is the membrane-bound important structure of the eukaryotic cell.
• The nucleus regulates all cellular activities by controlling the enzymes required for cellular processes. 
• It contains genetic information in the form of genes located in the chromosomes.
• It brings about the growth of the cell by directing the synthesis of structural proteins. It also controls all the metabolic activities of the cell.
  So, the correct answer is option D.

Solution

Correct answer is option C

Explanation for correct option:

• The primary distinction between these two types of organisms is that eukaryotic cells have a membrane-bound nucleus and prokaryotic cells do not.
• The prokaryotic ribosomes are small, 70 S ribosomes whereas the eukaryotic ribosomes are larger, 80S ribosomes.

Deoxyribonucleic acid (DNA) encodes the genetic instructions which are used in development and functioning of all living organisms. Ribonucleic acid (RNA) is one of the types of nucleic acid. Both, DNA and RNA are found in the nucleus. DNA is involved in coding the genetic information. It is present in the nucleoplasm of the nucleus in the tightly coiled form called as chromosomes. RNA is present in the nucleolus of the nucleus and involved in protein synthesis.
So, the correct answer is option A.

Prokaryotic cells are primitive cells. They do not possess many membrane bound organelles as mitochondria, lysosomes etc. They also do not have well defined membrane bound nucleus. Nuclear material of a prokaryotic cell consists of a single chromosome which is in direct contact with cytoplasm. Here, the undefined nuclear region in the cytoplasm is called as nucleoid, i.e., there is no nuclear membrane.