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

Death of cells when tissue is deprived of blood supply

  1. Proliferation

  2. Necrosis

  3. Ischemia

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

Necrosis is the term used to describe the premature death of cells in living tissue, often caused by factors such as lack of blood supply (ischemia), trauma, or toxins.

Multiple choice

Replacement of protective epithelial tissue

  1. Necrosis

  2. Re-epitheliazation

  3. Atrophic

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

Re-epithelialization is the replacement of protective epithelial tissue during wound healing. Necrosis is cell death, atrophic refers to wasting away, and chronic describes persistence.

Multiple choice bio-chemistry plant physiology active transport and passive transport types of plant transport atp

Select the odd one our w.r.t. porins.

  1. Not associated with the inner membrane of plastids

  2. Associated with the outer membrane of mitochondria

  3. Found in outer membrane of gram positive bacteria

  4. Allow movement of low molecular weight hydrophilic substances
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Porins are beta barrel proteins that cross a cellular membrane and act as a pore, through which molecules can diffuse. Unlike other membrane transport proteins, porins are large enough to allow passive diffusion, i.e., they act as channels that are specific to different types of molecules. Porins from non-green plastids and from the outer mitochondrial membrane were re- constituted into planar lipid bi-layers. The proteins showed high pore-forming activities and similar single- channel conductance. So, the correct option is "Not associated with the inner membrane of plastids".

Multiple choice botany plant water relation active transport and passive transport types of plant transport atp

Which of the following is zero in fully turgid cell?

  1. DPD and ${ \Psi } _{ P }$
  2. DPD and ${ \Psi } _{ W }$
  3. OP and ${ \Psi } _{ W }$
  4. TP and ${ \Psi } _{ P }$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

DPD is the difference in the diffusion pressure of the solution and a pure solvent when both are subjected to the same atmospheric pressure. When the increasing turgor pressure becomes equal to the decreasing osmotic pressure, the entry of the water into the cell would stop. This is called the turgid condition of the cell. This is when DPD equals zero.

Pressure potential is the positive pressure developed in the system due to the osmotic entry of water into it. It is negative in plasmolysed cell and xylem vessel and zero for the turgid cell.
Hence, the correct answer is 'DPD and ${ \Psi } _{ P }$'

Multiple choice

Cells that are necessary for you to convert Fe3+ to Fe2+

  1. Parietal Cells

  2. Chief Cells

  3. Enteroendocrine cells

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

Parietal cells secrete HCl, which provides the acidic environment necessary to convert ferric iron (Fe3+) to ferrous iron (Fe2+), the form that can be absorbed.

Multiple choice zoology health and diseases non-infectious diseases non infectious diseases categories of diseases

Cancer is a disorder of cell growth in a part of the body

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

  • Cancer is a class of diseases characterized by out-of-control cell growth. There are over 100 different types of cancer, and each is classified by the type of cell that is initially affected.
  • Cancer harms the body when damaged cells divide uncontrollably to form lumps or masses of tissue called tumors. Tumors can grow and interfere with the digestive, nervous, and circulatory systems, and they can release hormones that alter body function. Tumors that stay in one spot and demonstrate limited growth are generally considered to be benign.
So, the correct option is 'True'

Multiple choice zoology health and diseases non-infectious diseases non infectious diseases categories of diseases

Transformation of $C$. one into oncogene is known as?

  1. Carcinogen

  2. Oncogenic transformation

  3. Neoplastic cell

  4. Cancer cell
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Transformation of C.one into oncogene is known as carcinogen. A carcinogen is any substance, radionuclide or radiation that promotes carcinogenesis, the formation of cancer. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. 
So the correct option is 'Carcinogen'.
Multiple choice bio-chemistry life processes in living organisms- part 1 microbodies living organisms and energy production single membrane bound organelles

Which of the following is a phosphoryalting unit?

  1. Oxysome

  2. Vaculoes

  3. Peroxisome

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

Oxysomes are found in inner mitochondrial membrane and also called ad $F _1$ or elementary particles. It contains enzymes ATP synthase responsible for synthesis of ATP. They act as phosphorylating unit.

Multiple choice bio-chemistry structure and function of cell organelles microbodies living organisms and energy production single membrane bound organelles

Which one of the following is not considered as a part of the endomembrane system of eukaryotic cells?

  1. ER

  2. Lysosome and vacuoles

  3. Golgi complex

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

Endomembrane system of a eukaryotic cell is a membrane system that involves flow of membranes from one component to another by means of small membrane vesicles. The endomembrane system of a eukaryotic cell consists of endoplasmic reticulum, Golgi apparatus, lysosomes and plasma membrane.

Multiple choice bio-chemistry structure and function of cell organelles microbodies living organisms and energy production single membrane bound organelles

Which is not true about spherosomes?

  1. Arise from ER.

  2. Related to fat.

  3. Single membrane bound structure.

  4. Involved in photorespiration.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Spherosomes are membrane covered small spherical organelles which synthesize and store fats. They develop from endoplasmic reticulum. In some plants, spherosomes have lysosomal activity, e.g., maize root tip.

Multiple choice bio-chemistry structure and function of cell organelles microbodies living organisms and energy production single membrane bound organelles

Urate oxidase occurs in

  1. Lomasomes

  2. Peroxisomes

  3. Mitochondria

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

Peroxisomes are microbodies which have enzymes for peroxide metabolism. They include :
(a) Peroxide producing oxidative enzymes like peroxidase, urate oxidase or uricase, amino acid oxidase.
(b) Peroxide destroying enzymes like catalase. 

Multiple choice bio-chemistry structure and function of cell organelles microbodies living organisms and energy production single membrane bound organelles

What is degraded by peroxisomes?

  1. Carbon dioxide

  2. Hydrogen peroxide

  3. Lithium oxide

  4. Carbon monoxide
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Peroxisomes are microbodies which have enzymes for peroxide metabolism. They include : (a) Peroxide producing oxidative enzymes like peroxidase, urate oxidase or uricase, amino acid oxidase and (b) peroxide destroying enzymes like catalase.
Peroxisomes occur widely in animals cells, protists, fungi, higher plants but quite common in photosynthetic cells. In mesophyll cells, peroxisomes interact with chloroplasts, and mitochondria to take part in photorespiration.