Biology · Science General

Cell Biology and Structure

3,062 Questions

Cell biology focuses on the structure and function of cellular organelles. Key topics include cellular respiration, DNA inheritance, and energy production. These fundamental biology concepts are crucial for medical entrance and state service examinations.

Cell organelles functionsCellular respiration sitesDNA and ribosomesAnimal cell structurePlant cell components

Cell Biology and Structure Questions

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

The control centre of cell is

  1. Nucleus

  2. Mitochondria

  3. Nucleolus

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

The nucleus is an important cell organelle. It is the repository of genetic material. Inside nucleus, there is a synthesis of mRNA which is subsequently transported to the cytoplasm for protein synthesis. Thus, nucleus controls proteins synthesized in a cell and also is a repository of genetic material. Hence, the nucleus is controlling centre of the cell.

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

Nucleolemma is a part of

  1. Nuclear membrane

  2. Nuclear reticulum

  3. Nucleolus

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

Nucleo-lemma is a term used in parallel with plasma-lemma. The nucleo-lemma is a part of the nuclear membrane. The outer membrane may have ribosomes and interconnections with ER. Nuclear membrane has a large number of pores for the nucleo-cytoplasmic exchange of materials.

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

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

  1. Nucleosome

  2. Nucleolus

  3. Chromatin

  4. Circular DNA molecules
Reveal answer Fill a bubble to check yourself
D Correct answer
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.

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

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

  1. Nucleus

  2. Mitochondria

  3. Chloroplast

  4. Ribosome
Reveal answer Fill a bubble to check yourself
A Correct answer
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.
Multiple choice biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

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

  1. <font color="#222222">The nucleus is membrane-bound while the nucleolus is non-membrane bound.</font>

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

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

Nucleus is

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

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

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

  1. Endoplasmic reticulum

  2. Cell membrane

  3. Plasma membrane

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
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'.
Multiple choice biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

Which of the following separates the nucleoplasm with the cytoplasm?

  1. Cell membrane

  2. Nuclear membrane

  3. Endoplasmic reticulum

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

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

Nuclear pores are the passage through which movement of ...........(I) and ..........(II) molecules takes place between ...........(III) and ...........(IV).


Fill in the blanks (I - IV) by selecting the correct option.

I II III IV
(1) DNA RNA ER Cytoplasm
(2) RNA Protein Nucleus Cytoplasm
(3) DNA RNA Cytoplasm Nucleus
(4) Protein RNA Nucleus Nucleolus

  1. (1)

  2. (2)

  3. (3)

  4. (4)
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Nuclear pores  are the passage through which movement of RNA and protein molecules takes place between nucleus and cytoplasm.

So, the correct option is '(2)'.

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

From the following, identify which is the living matter of the cell.

  1. Chloroplast

  2. Endoplasmic reticulum

  3. Protoplasm

  4. Mitochondria
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

  • The living matter of cell is protoplasm which is the colorless material composed of a mixture of small molecules such as ions, amino acid etc.

So the correct answer is 'protoplasm'.

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

The nucleus is separated from the cytoplasm by ...........which is absent in .......... and present only in ......... The words filling the blanks are respectively

  1. Cell wall.bacteria and Amoeba

  2. Cell membrane , animals and prokaryotes

  3. Nuclear membrane, prokaryotes and eukaryotes

  4. Plasma membrane, eukaryotes and prokaryotes
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • The nucleus of a cell is separated from the cytoplasm by a double membrane known as the nuclear envelope.
  • Prokaryotes do not have genomic DNA that is concentrated and localized to a small area within the cell called nucleoid region, thus it is absent in them.
  • Whereas, a eukaryotic cell contains all the organelles and nucleus which is separated from the cytoplasm by the nuclear envelope.
  • The correct answer is OPTION C.
Multiple choice biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

.......... could be found in both, the nucleus and the cytoplasm.

  1. Nucleolus

  2. Ribosomes

  3. RNA

  4. Both B and C
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

  • RNA is found everywhere- nucleus, nucleolus, mitochondria, chloroplasts, ribosomes, cytoplasm, etc. RNAs are 3 different types- mRNA, tRNA and rRNA. mRNA and tRNA are found in the cytoplasm and rRNA in the nucleus.
  • The ribosomes can be free within the cytoplasm of a cell or attached to the endoplasmic reticulum but do not present inside the nucleus. RNA and ribosomes act together resulting in the synthesis of proteins.

 Hence, the correct answer is option C.

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

Which of the following is correct : 

  1. cell of all living organisms have a nucleus.

  2. Both animal and plant cells have a well defined cell wall.

  3. In prokaryotes, there are no membrane bound organelles.

  4. Cells are formed de novo from abiotic materials.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation


  • The cell is the basic structural, functional, and biological unit of all known living organisms. A cell is the smallest unit of life. 
  • Cells are often called the "building blocks of life". 
  •  Cells are of two types: eukaryotic, which contain a nucleus, and prokaryotic, which do not. 
  • Prokaryotes are single-celled organisms, while eukaryotes can be either single-celled or multicellular. 
  • Hence, the cell of all living organisms have a nucleus is correct.
  • So, the correct answer is 'cell of all living organisms has a nucleus'.