Tag: biology

Questions Related to biology

Which of the following is not contained in a eukaryotic nucleus?

biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

  1. Nucleosome

  2. Nucleolus

  3. Chromatin

  4. Circular DNA molecules

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Correct Option: D
Explanation:

Prokaryotic cells like bacteria have a single circular DNA molecule as their genetic material which is also called as a bacterial chromosome. The eukaryotic cells have a prominent nucleus with species-specific number of linear chromosomes having well-defined centromere and telomeres.

The "master mind" of the cell is

biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

  1. Protoplast

  2. Nucleolus

  3. Nucleus

  4. Plastid

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Correct Option: C
Explanation:
  • The nucleus controls protein synthesis and is the genetic repository of a cell. 
  • Hence, the nucleus can be called as the mastermind of cell.
  • Thus, option C is correct.

rDNA is present in

biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

  1. NOR

  2. Telomere

  3. Centromere

  4. Kinetochore

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Correct Option: A

Name the cell organelle which is called the 'Control room of the cell'.

biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

  1. Nucleus

  2. Mitochondria

  3. Chloroplast

  4. Ribosome

Show answer
Correct Option: A
Explanation:
The nucleus is the most important part of the cell which regulates all the cellular activities by controlling the enzymes required for cellular processes. Enzymes are proteins and protein synthesis is controlled by nucleus as mRNA required for protein synthesis is made from DNA, which is situated in the nucleus. Hence, the nucleus is the control room of the cell.
So, the correct answer is option A.

The mature mammalian red blood cells are incapable of further division because

biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

  1. DNA sequences are redundant

  2. The nuclei are lobed

  3. They lack nuclei

  4. The mitotic apparatus is absent

Show answer
Correct Option: C
Explanation:

Because of the lack of nuclei and organelles, mature red blood cells do not contain DNA and cannot synthesize any RNA, and consequently can not divide and have limited repair capabilities. 

So, the correct option is C. (They lack nuclei)

Which of the following statements about nucleus and nucleolus is right?

biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

  1. The nucleus is membrane-bound while the nucleolus is non-membrane bound.

  2. The nucleolus is membrane-bound while the nucleus is non-membrane bound.

  3. Both nucleolus and nucleus are membrane bound

  4. Both nucleus and nucleolus are not membrane bound.

Show answer
Correct Option: A
Explanation:

The nucleus is a membrane-bound structure which is separated from the cytoplasm. This membrane is a nuclear membrane which has small pores which allow diffusion. The nucleolus is the centre dark part of the nucleus which is not surrounded by any kind of membrane. It is distinguished from nuclear material by its colour only.

So, the correct option is 'The nucleus is membrane-bound while the nucleolus is non-membrane bound'.

Nucleus is

biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

  1. The largest organelle in the cell

  2. The organelle which contains chromosomes

  3. The organelle with a double membrane

  4. All of the above

Show answer
Correct Option: D
Explanation:

The Nucleus is the largest cell organelle which contains the chromosomes. The nucleus has a nuclear membrane which is made up of two layers i.e it is and organelle with a double-membrane.

The Control center of the cell is

biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

  1. the Nucleus

  2. the Cytoplasm

  3. the Nucleolus

  4. All of the above

Show answer
Correct Option: A
Explanation:

The nucleus is considered as the control center of the cell as it has all the information for controlling the various components of the cell and keeping the cell alive.

Which of the following divides the intracellular space into two distinct compartments?

biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

  1. Endoplasmic reticulum

  2. Cell membrane

  3. Plasma membrane

  4. None of the above

Show answer
Correct Option: A
Explanation:
The endoplasmic reticulum is a network of membranous tubules within the cytoplasm of a eukaryotic cell, continuous with the outer nuclear membrane. It usually has ribosomes attached and is involved in protein and lipid synthesis. The endoplasmic reticulum divides the intracellular space into two distinct compartments, viz. luminal and extra-luminal.
So, the correct answer is 'Endoplasmic reticulum'.

Which of the following separates the nucleoplasm with the cytoplasm?

biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

  1. Cell membrane

  2. Nuclear membrane

  3. Endoplasmic reticulum

  4. Golgi body

Show answer
Correct Option: B
Explanation:

Nuclear membrane is a double layered membrane, made up of lipid bilayer and proteins that separates the nucleus from the rest of the cell. The cytoplasm contains the most of the hydrolytic enzymes, which can affect the genetic material. The membrane protects the genetic material from different chemical reactions. It decides what to enter and exit from the nucleus by acting selectively permeable. It also provides structural support to the nucleus.