Tag: microscopy

Questions Related to microscopy

Cause of chromosome laggards in meiosis is?

botany nucleus and chromosome membrane bound organelles cell: size and differentiation microscopy

  1. Inversion

  2. Dicentric chromosome

  3. Acentric chromosome

  4. Duplication of a gene

Show answer
Correct Option: B
Explanation:
A laggard is defined as a chromosome that does not overlap along the long axis of the spindle with any of the properly segregating chromosomes. A dicentric chromosome is an abnormal chromosome with two centromeres. It is formed through the fusion of two chromosome segments, each with a centromere, resulting in the loss of acentric fragments (lacking a centromere) and the formation of dicentric fragments.

So, the correct answer is 'Dicentric chromosome'.

What are the spindle fibres that connect the centromere of chromosome to the respective poles called?

botany nucleus and chromosome membrane bound organelles cell: size and differentiation microscopy

  1. Astral rays

  2. Interpolar fibres

  3. Chromosomal fibres

  4. Inter chromosomal fibres

Show answer
Correct Option: C
Explanation:
The central region of the chromosome where the two arms of chromatid are attached is called as the centromere. It is the region where the spindle fibers attach at the time of the cell division and are called as chromosomal fibers. 
Thus the correct answer is option C. 

Which of the following is not the function of a vacuole?

botany cell structure and organization membrane bound organelles cell: size and differentiation microscopy

  1. Storage

  2. Providing turbility and rigidity to the cell

  3. Waste excretion

  4. Locomotion

Show answer
Correct Option: D
Explanation:

The vacuole are the membranous vesicular structures in the cells of the living organisms. The vacuoles are involved in the storage of the food materials. The presence of vacuole provides rigidity and shape to the cell with the help of turbulence. The wastes from the cells can be excreted with the help and movement of the vacuoles. The vacuoles are not responsible for locomotion. 

Thus, the correct answer is option D. 

When a fresh water protozan is placed in marine water

botany cell structure and organization membrane bound organelles cell: size and differentiation microscopy

  1. The contractile vacuole disappears

  2. The contractile vacuole increases in size

  3. A number of contractile vacuoles appear

  4. The contractile vacuole remains unchanged

Show answer
Correct Option: A
Explanation:

Contractile vacuoles are membrane-bound organelles that pump excess water out of the protozoan. When the freshwater protozoan is placed in a marine environment it loses water due to exosmosis as salt concentration is high outside. The contractile vacuole disappears to prevent the loss of water from the organism because in the presence of contractile vacuoles the cell will be dehydrated. 

Thus the correct answer is option A.

Spindle chromosomes have

botany nucleus and chromosome membrane bound organelles cell: size and differentiation microscopy

  1. Centriole

  2. Kinetochore

  3. Chromocentre

  4. Chromomere

Show answer
Correct Option: B
Explanation:

Chromosomes when attached to spindle fibres are called as spindle chromosomes. These Chromosomes have narrow very lightly coloured centromere or primary constriction. The centromere has a proteinaceous covering called as kinetochore on the two free surface of the centromere complex. The kinetochore has centromere binding proteins.

Vacuoles are formed by the fusion of 

botany cell structure and organization membrane bound organelles cell: size and differentiation microscopy

  1. Cytoplasm

  2. Golgi apparatus

  3. Vesicles

  4. None of the above

Show answer
Correct Option: C
Explanation:

Vacuoles are the membrane-bound storage organelle formed by the fusion of multiple membrane vesicles. It does not have fixed shape and varies according to the need.

Outermost layer surrounding the vacuole is 

botany cell structure and organization membrane bound organelles cell: size and differentiation microscopy

  1. Tonoplast

  2. Vacuolar Membrane

  3. Both A and B

  4. Vacuolar cell wall

Show answer
Correct Option: C
Explanation:

A vacuole is the double membrane bound structure. The outermost covering of vacuole is called as tonoplast or vacuolar membrane. The tonoplast is the cytoplasmic membrane separating the vacuolar contents from the cell's cytoplasm. Therefore, the correct answer is option C.

Which out of the following is not a function of vacuole?

botany cell structure and organization membrane bound organelles cell: size and differentiation microscopy

  1. Storage

  2. Providing turgidity and rigidity to the cell

  3. Waste excretion

  4. Locomotion

Show answer
Correct Option: D
Explanation:

The vacuole is the membrane bound cell organelle and has the main function of osmoregulation. It also stores fluid and solid and hence, maintains rigidity of cell. In some organism vacuole involves in the excretion of wastes. Thus, the correct answer is option D.

'Storage sac of the cell' is ___________________

botany cell structure and organization membrane bound organelles cell: size and differentiation microscopy

  1. Ribosome

  2. Chloroplast

  3. Vacuole

  4. Golgi body

Show answer
Correct Option: C
Explanation:

Vacuoles are the membrane-bound organelle filled with water containing inorganic and organic molecules including. In-plant cells, it is large and centrally located whereas, in animal cells, it is either small or absent. It is also called as storage sac as it stores water, food and waste materials.
So, the correct answer is option C.

Which one of the following is not the function of a vacuole?

botany cell structure and organization membrane bound organelles cell: size and differentiation microscopy

  1. Storage

  2. Providing turgidity and rigidity to the cell

  3. Waste excretion

  4. Locomotion

Show answer
Correct Option: D
Explanation:

The vacuole is the membrane bound organelle mainly found in the plant cell. In plant cell it large and centrally located. It has three major functions  such as:
1. Contribute to the rigidity of the plant using water to develop hydrostatic pressure.
2. Store nutrient and non-nutrient chemicals.
3. Break down complex molecules.
Thus, the correct answer is option D.