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 botany cell theory, cell specialization, and cell replacement number and shape of cells unicellular and multicellular organisms diversity and classification in animals

Metabolically active cells have

  1. Lower nucleocytoplasmic ratio.

  2. Higher nucleocytoplasmic ratio.

  3. Higher surface: volume ratio.

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

Metabolically active cells require efficient exchange (high surface area to volume ratio) and often have a large nucleus to manage cellular processes (higher nucleocytoplasmic ratio).

Multiple choice botany cell theory, cell specialization, and cell replacement number and shape of cells unicellular and multicellular organisms diversity and classification in animals

Volumes of prokaryotic and eukaryotic cells are ........... respectively.

  1. $0.2-10\mu {m}^{3}$ and $1000-10000\mu {m}^{3}$
  2. $0.1-10\mu {m}^{3}$ and $100-1000\mu {m}^{3}$
  3. $0.1-5.0\mu {m}^{3}$ and $3-30\mu {m}^{3}$
  4. $0.1-1.0\mu {m}^{3}$ and $10-100\mu {m}^{3}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Prokaryotic cells are generally much smaller, typically in the range of 0.2 to 10 cubic micrometers, while eukaryotic cells are significantly larger, ranging from 1000 to 10000 cubic micrometers.

Multiple choice botany cell theory, cell specialization, and cell replacement number and shape of cells unicellular and multicellular organisms diversity and classification in animals

A bacterium divides every 35 minutes . If a culture containing $ 10^5$ cell per ml is grown for 175 minutes. What will be the cell concentration per ml after 175 mts _______________.

  1. $32 \times 10^5$ cells
  2. $5 \times 10^5$ cells
  3. $35 \times 10^5$ cells
  4. $175 \times 10^5$ cells
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
It is given that a bacterium divides every 35 minutes,
At 0 minutes, the culture contains $ 10^5 $ cells/ml.
After 35 minutes, the culture will contain $ 2^1 \times 10^5 $ cells / ml
similarly, after 175 minutes, that is after 5 generations, the no. of cells
$ = 2^{5} \times 10^{5}$ cells/ml.
This is equal to $ 32 \times 10^{5} $ cell/ml
So, (A) is the correct answer.
Multiple choice botany cell theory, cell specialization, and cell replacement number and shape of cells unicellular and multicellular organisms diversity and classification in animals

The average volume of a eukaryotic cell is

  1. Between 1 $\mu \, m^3$ and 1,000 $\mu \, m^3$
  2. Between 100 $\mu \, m^3$ and 1,000 $\mu \, m^3$
  3. Between 10 $\mu \, m^3$ and 100 $\mu \, m^3$
  4. Generally greater than 10,000 $\mu \, m^3$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A cell of 1 μm^3 volume average to the maximum 1,000 μm^3 most highly expressed proteins in a cell.

So, the correct option is 'Between 1 μm^3 and 1,000 μm^3'.

Multiple choice zoology skeleton and movements introduction to movement introduction to locomotion movement

Taxis is movement in

  1. Single cell

  2. Single-celled organism

  3. Cell organelles

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

Taxis is a kind of behavioural response of a cell, cell organelles or an organism to an external stimulus such as light or food. It is the orientation of an organism or a cell in a specific spatial relationship to a stimuli. If the movement is towards the stimuli it is positive taxis and if it is away from the stimuli it is negative taxis. 

Thus, the correct answer is option D. 

Multiple choice biology respiration amphibolic pathway living organisms and energy production life processes in living organisms- part 1

Mitochondria is the site for

  1. Krebs cycle

  2. Calvin cycle

  3. Anaerobic respiration

  4. Trapping of sun light
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • The citric acid cycle is also known as the TCA cycle (tricarboxylic acid cycle) or the Krebs cycle. 
  • It is a series of chemical reactions used by all aerobic organisms to release stored energy through the oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins, into adenosine triphosphate (ATP) and carbon dioxide.
  •  In eukaryotic cells, the citric acid cycle occurs in the matrix of the mitochondrion.
  •  In prokaryotic cells, such as bacteria, which lack mitochondria, the citric acid cycle reaction sequence is performed in the cytosol. 
  • Hence, Mitochondria is the site for the Krebs cycle.
  • So, the correct answer is 'Krebs cycle'.
Multiple choice botany biotechnology and genetic engineering use of microbes in biotechnology use of microbes in industrial applications useful microorganisms

In a microbiology laboratory, the technician uses heat to sterilise the nutrient solution that is used to grow 4. a fungus. When the heating system broke down, he sterilised the solution by passing It on a sterile environment) through a sterile filter with a pore size of 0.2 micrometers. When the fungus was grown on the filtered nutrient solution, it stopped growing and looked unhealthy within a few days. Which statements is the most likely explanation for the observed effects on the fungus ?

  1. The nutrient solution contained a virus

  2. Heating makes the glucose in the nutrient solution more digestible

  3. Filtering removed one of the larger nutrients

  4. The nutrient solution contained a bacterium that was pathogenic to the fungus.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A) Viruses inhibit the growth of other organisms by entering the host organism and using its genetic material and nutrition to reproduce. Hence, the fungus stops growing.

B) The fungus absorbs glucose. Heating glucose will destroy it and the fungus will not be able to digest it.
C)  Glucose is a micro-molecule which passes through the filter. The fungus mainly requires glucose to survive. Filtering did not affect the fungus.
D) Bacteria are too large to penetrate the filter and hence cannot affect the fungus.
So the correct answer is 'The nutrient solution contained a virus'.

Multiple choice zoology important and common human diseases diseases caused by changes in lifestyle diseases and toxic substance non-infectious diseases

Cells obtained from cancerous tumours are known as

  1. Hybridoma

  2. Lymphocyte

  3. Monoclonal cells

  4. Myeloma
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • Myeloma, also known as multiple myeloma, is a blood cancer arising from plasma cells. 
  • Plasma cells are a type of white blood cell made in the bone marrow. Bone marrow is the ‘spongy’ material found in the centre of the larger bones in the body and is where all blood cells are made. 
  • Myeloma develops when DNA is damaged during the development of a plasma cell. 
  • This abnormal cell then starts to multiply and spread within the bone marrow.
  • Hence, Cells obtained from cancerous tumours are known as Myeloma.
  •  So, the correct answer is 'myeloma'.
Multiple choice zoology important and common human diseases diseases caused by changes in lifestyle diseases and toxic substance non-infectious diseases

Which one of the following in not a feature of cancerous cells?

  1. They divide in an uncontrolled manner.

  2. They do not remain confined to one localized area.

  3. They compete with normal cells for vital nutrients.

  4. They show contact inhibition.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Cancer is a group of disease, that involves abnormal cell growth (abnormal cell division), with the potential to invade or spread to other parts of the body. They compete with normal cells for nutrients. Contact inhibition is a growth mechanism, which functions to keep cells growing into a layer one cell thick or monolayer. The cancer cells do not show contact inhibition and they grow uncontrollably.
Thus, the correct answer is option (D), 'They show contact inhibition'.

Multiple choice zoology important and common human diseases diseases caused by changes in lifestyle diseases and toxic substance non-infectious diseases

HeLa cells used in cell biology are

  1. Cancerous cells grown in cancer research laboratory

  2. Cervial cancer cell derivatives

  3. Both A and B

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

  • HeLa cells are the cell type in immortal cell lines used in scientific research. It is the oldest and most commonly used human cell line.
  • The line was derived from cervical cancer cells taken on February 8, 1951, from Henrietta Lacks, a patient who died of her cancer on October 4, 1951.  These cells are grown in a laboratory and are used for conducting many experiments.
Thus, the correct answer is option C.

Multiple choice zoology important and common human diseases diseases caused by changes in lifestyle diseases and toxic substance non-infectious diseases

Cancer cells are characterized by

  1. Uncontrolled growth

  2. Invasion of local tissue

  3. Spreading to other body parts

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

Cancer is a group of diseases involving the abnormal cell growth where there is invasion of the local tissue and there is a potential to invade or spread to other body parts .
Therefore, the correct answer is option D.

Multiple choice zoology important and common human diseases diseases caused by changes in lifestyle diseases and toxic substance non-infectious diseases

Which one of the following is not a property of cancerous cells?

  1. They compete with normal cells for vital nutrients.

  2. They do not remain confined in the area of formation.

  3. They divide in an uncontrolled manner.

  4. They show contact inhibition.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

During tumorigenesis, cancerous cells undergo rapid cell division and compete with normal cells for nutrients.
Cancer cells spread to other parts of the body, a process called metastastize i.e., are not confined in area  of formation.
Cancer is the result of cells that uncontrollably grow and do not die.
So, statements A, B and C are correct.
Normal cells when grown in culture, will become growth inhibited, when they encounter another cell. This is contact inhibition and Cancer cells show no contact inhibition as they do not stop dividing and keep growing.
Thus, the correct answer is option (D), 'They show contact inhibition'.

Multiple choice zoology important and common human diseases diseases caused by changes in lifestyle diseases and toxic substance non-infectious diseases

................. is the process by which cancer cells spread from one region of the body to other 

  1. Hypostasis

  2. Metastasis

  3. Parastasis

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

Metastasis is the movement of spreading of cancer cells from one organ or tissue to another. Cancer cells usually spread through the blood or the lymph system. It is mainly caused due to the mutagens which cause a sudden heritable change in the DNA content which leads to fatal abnormalities.
So, the correct answer is option B.

Multiple choice zoology important and common human diseases diseases caused by changes in lifestyle diseases and toxic substance non-infectious diseases

Cancer cells are characterised by 

  1. Uncontrolled growth

  2. Spreading to the other body part

  3. Invasion of local tissue

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

Cancer cells are cells that divide rapidly, forming solid tumours or flooding the blood with abnormal cells. Malignant cancerous cells spread from their initial site to other organs or tissues resulting in metastasis. Cancer cells undergo invasion of local tissue i.e., direct extension and penetration by cancer cells into neighbouring tissues. Hence, cancer cells are characterised by uncontrolled growth, spreading to other body part and invasion of local tissue.

So, the correct answer is 'All of the above'.