Which of the following statements can explain the fact that many scientists do not consider viruses as living organisms?
1. Metabolism and growth are defining properties of living organisms.
2. Anything less than a complete structure of a cell does not ensure independent living.
3. All cells arise from pre-existing cells
4. All biochemical reactions are catalyzed by enzymes.
A non-membrane bound organelle found in all cells is:
1. Centriole
2. Lysosome
3. Vacuole
4. Ribosome
Spindle fibers are attached to the chromosome in the region of :
1. Centrosome
2. Chromomere
3. Chromonema
4. Kinetochore
Identify the human cell for which the interphase period lasts the entire life of a person.
1. Hepatocyte
2. Bone marrow stem cells
3. Epidermal cell
4. Neuron
Identify the appendage present on the surface of some bacterial cells that help attach them to rocks in streams and also to the host tissues:
1. Flagella
2. Pili
3. Fimbriae
4. Cilia
Most of the functions of a cell membrane can be attributed to its:
1. Phospholipids
2. Cholesterol
3. Proteins
4. Carbohydrates
An enzyme brings about :
1. Decrease in reaction time
2. Increase in reaction time
3. Increase in activation energy
4. Reduction in activation energy
Consider the following functions:
I. Replication of DNA along with the synthesis of nuclear proteins such as histones
II. Duplication of centriole
III. Synthesis of energy rich compounds and proteins
Which of the above functions are carried out by a plant cells before it divides?
1. I only
2. I, and II
3. I and III
4. I, II, and III