Tag: botany

Quizzes (264) Questions (5276)

Questions Related to botany

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

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

  1. Astral rays

  2. Interpolar fibres

  3. Chromosomal fibres

  4. Inter chromosomal fibres
Reveal answer Fill a bubble to check yourself
C Correct answer
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. 
Multiple choice botany cell structure and organization membrane bound organelles cell: size and differentiation microscopy

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

  1. Storage

  2. Providing turbility and rigidity to the cell

  3. Waste excretion

  4. Locomotion
Reveal answer Fill a bubble to check yourself
D Correct answer
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. 

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

When a fresh water protozan is placed in marine water

  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
Reveal answer Fill a bubble to check yourself
A Correct answer
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.

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

Spindle chromosomes have

  1. Centriole

  2. Kinetochore

  3. Chromocentre

  4. Chromomere
Reveal answer Fill a bubble to check yourself
B Correct answer
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.

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

Outermost layer surrounding the vacuole is 

  1. Tonoplast

  2. Vacuolar Membrane

  3. Both A and B

  4. Vacuolar cell wall
Reveal answer Fill a bubble to check yourself
C Correct answer
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.

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

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

  1. Storage

  2. Providing turgidity and rigidity to the cell

  3. Waste excretion

  4. Locomotion
Reveal answer Fill a bubble to check yourself
D Correct answer
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.

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

'Storage sac of the cell' is ___________________

  1. Ribosome

  2. Chloroplast

  3. Vacuole

  4. Golgi body
Reveal answer Fill a bubble to check yourself
C Correct answer
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.

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

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

  1. Storage

  2. Providing turgidity and rigidity to the cell

  3. Waste excretion

  4. Locomotion
Reveal answer Fill a bubble to check yourself
D Correct answer
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.

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

Centromere is required for -

  1. Movement of chromosomes towards poles

  2. Cytoplasmic cleavage

  3. Crossing over

  4. Transcription
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Centromere is present in every cell. It is a specific DNA sequence in a chromosome. It is specifically useful in the process of cell division. During mitosis, the spindle fibres attach to the centromeres via kinetochore and all the chromosomes are arranged in an equatoral plane. After this, the chromosomes move towards their respective poles and cell division takes place.

So, option A is the correct answer.