Biology · Science General

Cell Biology and Structure

3,221 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 tissues, organs, organ system, organism defense mechanism in plants epidermal tissue system permanent tissues and their types

Which of the following is an epidermal cell?

  1. Guard cells

  2. Root hairs

  3. Trichome

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • Epidermal cells from the outer covering or surface which is mainly involved in protection and secretion. Guard cells, root hairs, and trichome are all modification of the epidermal cells.
(i) Root hair
Structure: 
  • Unicellular hairs are the extensions of an epidermal cell of roots in the root hair zone.
Function:
It increases the surface area for absorption of water and minerals.
(ii) Epidermal appendages
Structure:
  • These are called trichomes and are epidermal cell modifications. There may be unicellular or multicellular.
Functions:
Some perform for stinging produces and some glandular secretions.
(iii) Guard cell
  • Structure:
These are bean-shaped cells present on the epidermis of the leaf.
Functions:
These help in gaseous exchange and transpiration.

Multiple choice botany plant tissues defense mechanism in plants epidermal tissue system permanent tissues and their types

Which one of the following can be considered to be a dead mechanical tissue?

  1. Aerenchyma

  2. Collenchyma

  3. Parenchyma

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

Sclerenchyma tissue is composed of dead cells with heavily lignified secondary cell walls, providing mechanical strength and support to plant organs. In contrast, parenchyma, collenchyma, and aerenchyma are generally living tissues at maturity.

Multiple choice botany plant tissues defense mechanism in plants epidermal tissue system permanent tissues and their types

Match the following and choose the correct option from below.

A. Cuticle (i) Guard cells
B. Bulliform cells (ii) Single layer
C. Stomata (iii) Waxy layer
D. Epidermis (iv) Empty colourless cell

  1. A-(iii), B-(iv), C-(i), D-(ii)

  2. A-(i), B-(ii), C-(iii), D-(iv)

  3. A-(iii), B-(ii), C-(iv), D-(i)

  4. A-(iii), B-(ii), C-(i), D-(iv)
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A. Cuticle: It is a fatty substance( cutin) deposited over the surface of epidermal cells in the form of a separate layer. Usually, the cuticle is covered with wax which may be deposited in the form of granules, rods, crusts or viscous semi-liquid masses.

B. Bulliform cells: They are thin-walled and contain big vacuoles filled with water. They play an important role in folding and unfolding of leaves.
C. Stomata: A typical stoma is microscopic and usually consists of two kidney-shaped guard cells surrounding a pore.
D. Epidermis: The epidermis of most of the plant is single-layered (uniseriate) but in some cases, it may be more than one layer thick (multiseriate).
So, the correct answer is 'A-(iii), B- (iv), C-(i), D-(ii)'.

Multiple choice botany bacteria bacteria - introduction, shape and structure bacteria: types and structure bacteria; benefits and harmful effects non cellular organism : virus world of virus

Hens egg is

  1. An organ

  2. A single cell

  3. A tissue

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Hens egg is a single cell structure inside the shell before the fertilization that can be seen by naked eyes. But after fertilization, the cells fused and divide into two cells inside the shell.

Hence, option B is correct.

Multiple choice botany the world of microbes bacteria - introduction, shape and structure bacteria: types and structure bacteria; benefits and harmful effects non cellular organism : virus world of virus

Which of the following is the location of mucilage capsule present in bacteria which serves as an extra covering?

  1. Outside the cell membrane

  2. Inside the cell membrane

  3. Outside the cell wall

  4. Inside the cell wall
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The mucilage capsule present in bacteria serving as an extra covering is present outside the cell because it is a temporary layer surrounding the cell wall and protects the bacteria from antibiotics and dessication.

So, the correct option is C.

Multiple choice botany the world of microbes bacteria - introduction, shape and structure bacteria: types and structure bacteria; benefits and harmful effects non cellular organism : virus world of virus

Membrane bound organelles are absent in 

  1. Plasmodium

  2. Saccharomyces

  3. Streptococcus

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

Membrane bound organelles are absent in prokaryotes. As compared to a eukaryotic cell, the only comparable organelles present in prokaryotes are ribosomes which are naked nucleoprotein particles. Plasmodium is a unicellular eukaryotic organism which belongs to Kingdom Protista. Saccharomyces is also a unicellular eukaryotic organism which belongs to Kingdom Mycota or Fungi. Streptococcus is a unicellular prokaryotic organism which belongs to Kingdom Monera. Chlamydomonas is a unicellular eukaryotic organism, previously classified under Kingdom Plantae as Chlorophyceae but has now been moved to Kingdom Protista. Of the given options only Streptococcus is a prokaryotic organism. Hence, membrane bound cell organelles are missing in Streptococcus.

Multiple choice botany the world of microbes bacteria - introduction, shape and structure bacteria: types and structure bacteria; benefits and harmful effects non cellular organism : virus world of virus

Many bacteria bear minute hairy structures on their cell wall which are involved in genetic transfer are called as

  1. Hairs

  2. Flagella

  3. Pili

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

Pili are minute hair like appendages, that emerges from suface of Gram -ve bacteria. They have similar structure as flagella and often involved in attachment to surface and making of biofilm. They also help in DNA exchange. They are involved in conjugation which results in transfer or exchange of genetic material. 

Multiple choice botany bacteria bacteria - introduction, shape and structure bacteria: types and structure bacteria; benefits and harmful effects non cellular organism : virus world of virus

Binary fission in Amoeba involves ____________.

  1. Amitosis

  2. Mitosis

  3. Meiosis

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The reproduction in amoeba is asexual, called binary fission, where it replicated its cells by mitosis and its cell divide in two equal daughter cells. Amitosis is similar to binary fission. Meiosis does not take place in amoeba.

The correct answer is B. 

Multiple choice botany bacteria bacteria - introduction, shape and structure bacteria: types and structure bacteria; benefits and harmful effects non cellular organism : virus world of virus

Amoeba takes food through ____________.

  1. Phagocytosis

  2. Pinocytosis

  3. Endocytosis

  4. All the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Amoeba takes its food by the method of phagocytosis (i.e ingesting or engulfing the food particles), also by means of pinocytosis (wherein amoeba wraps around its membranes around the food forms vesicles and pinch it inside the membrane and then gradually digests it) and by endocytosis (in which the outermost the membrane of amoeba either stretches inwards or projects outwards to obtain nutrition.

The correct answer is D.

Multiple choice botany the world of microbes bacteria - introduction, shape and structure bacteria: types and structure bacteria; benefits and harmful effects non cellular organism : virus world of virus

In bacteria the site for respiratory activity is found in

  1. Episome

  2. Microsome

  3. Ribosome
  4. Cell membrane$/$ Mesosome
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In bacteria the site for respiratory activity is found in mesosomes. Mesosomes are folded invaginations in the cell membrane of bacteria. They increases the surface area required for respiration. They contain respiratory enzymes. It is the site of respiratory activity.

Thus, the correct answer is 'Cell membrane/ Mesosome.'

Multiple choice botany the world of microbes bacteria - introduction, shape and structure bacteria: types and structure bacteria; benefits and harmful effects non cellular organism : virus world of virus

Bacterial cell membrane is made up of

  1. Chitin

  2. Cellulose

  3. Proteins and phospholipids

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

Bacteria is a unicellular prokaryotic organism. It has a cell wall around the cell membrane. The bacterial cell membrane is made up of proteins and phospholipids. the proteins in are randomly distributed in the phospholipid bilayer of the cell membrane.

Thus, the correct answer is 'Proteins and phospholipids.'

Multiple choice botany the world of microbes bacteria - introduction, shape and structure bacteria: types and structure bacteria; benefits and harmful effects non cellular organism : virus world of virus

Some bacteria have a capsule outside cell wall. It is made of

  1. Protein

  2. Cellulose

  3. Fat

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

Some bacteria have a capsule outside cell wall. It is made up of mucopolysaccharide. The functions of mucopolysaccharide are;

  • It enhances the ability of bacteria to cause disease. 
  • It protects cells from engulfment by macrophages. 
  • It protects cells from desiccation.
Thus, the correct answer is 'Mucopolysaccharide.'

Multiple choice botany the world of microbes bacteria - introduction, shape and structure bacteria: types and structure bacteria; benefits and harmful effects non cellular organism : virus world of virus

Which one of the following is absent in eukaryotes?

  1. Nucleolus

  2. Plastid

  3. Mesosome

  4. Ribosomes
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • Mesosomes are absent in eukaryotes.
  • Mesosomes refers to the folded invaginations in the plasma membrane of prokaryotes or bacterial cells.
  • Its main function is to increase the surface area of the plasma membrane. 
  • When the surface area of the membrane is increased it helps to carry out the cellular respiration more efficiently.
  • So, the correct answer is 'Mesosome'.