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 nutrition - food supplying system site of photosynthesis chloroplast and pigments of photosynthesis pigments action spectrum and absorption spectrum spectrum of electromagnetic radiation

Which cellular part is correctly described

  1. Thylakoids - Flattened membranous sacs forming grana

  2. Centrioles - Sites for active RNA synthesis

  3. Ribosomes - Those in chloroplasts are larger (80 S) while those in cytoplasm are smaller (70 S)

  4. Lysosomes - Opimally active at 8.5 pH.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Thylakoids are indeed flattened membranous sacs that stack to form grana. Centrioles are for spindle formation, not RNA synthesis. Chloroplast ribosomes are 70S, not 80S. Lysosomes are acidic (pH 5).

Multiple choice biology cell structure and micro-organisms animal cell plant and animal cell cell structure

Read the different combinations of terms given below. The correct combination of terms with reference to an animal cell is : 

  1. Cell wall, Cell membrane, Nucleus, Plastid

  2. Cell wall, Nucleus, Ribosome, Chromosome

  3. Cell membrane, Ribosome, Mitochondria, Chromosome

  4. Cell membrane, Ribosome, Mitochondria, Chloroplast
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • Animal cells are typical of the eukaryotic cell, enclosed by a plasma membrane and containing a membrane-bound nucleus and organelles like ribosomes, mitochondria etc. 
  • Unlike the eukaryotic cells of plants and fungi, animal cells do not have a cell wall. 
  • Hence, The correct combination of terms with reference to an animal cell is cell membrane, ribosome, mitochondria, chromosome.
  • So, the correct answer is 'cell membrane, ribosome, mitochondria, chromosome'.
Multiple choice biology cell structure and micro-organisms animal cell plant and animal cell cell structure

How many types of cells in human body are known, based on the tissues they form?

  1. Six

  2. Seven

  3. Eight

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

Human body has eight type of cells based on the tissues formed by them. They are as followed:

1) Bone cells known as osteocytes helps in the formation of bone which is a connective tissue.
2)  Cartilage cells helps in the formation of flexible cartilage and provides flexibility to parts like auricle.
3)  Nerve cells forms the nervous system and helps in transmission of nerve signal.
4) Epithelial cell forms the covering of other cells. It also helps in wear and tear mechanism.
5)  Muscle cells are present in the muscle tissue. It is rich in actin and myosin and help in muscle contraction.
6) Secretory cell form glands and secrete hormones, oil and enzymes. For example, pancreatic cells which secrete insulin, glucagon, salivary gland secrete salivary amylase, sebaceous gland secrete oil on the skin etc.They are found in all secretory organs.
7)  Adipose cells forms adipose tissue and helps in storage of fat.
8) Blood cells include RBC’s, WBC, Thormbocytes etc. RBC carry haemoglobin and helps in respiration. WBC plays active role in defensive mechanism and thromocytes helps in blood clotting with the help of thromboplastin.
So, the correct answer is option C.

Multiple choice biology cell structure and micro-organisms animal cell plant and animal cell cell structure

Which of the following structures helps you to determine that it is not an animal cell?

  1. Cell wall and Vacuole

  2. Mitochondria and Ribosome

  3. Ribosomes and Lysosomes

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

Plant cell is surrounded by cell wal while the animal cell is starts with plasma membrane. The vacuoles are dispersed in animal cell while the plant cell has a large central vacuole.

So, the correct answer is option A.

Multiple choice biology cell structure animal cell plant and animal cell cell structure and micro-organisms

Thread like protoplasmic projections found on free surface of absorptive cells are

  1. Cilia

  2. Microfilaments

  3. Microvilli

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

Microvilli are microscopic cellular membrane protrusions that increase the surface area of cells and are involved in a wide variety of functions including absorption, secretion, cellular adhesion and mechanotransduction.

Multiple choice biology cell structure and micro-organisms animal cell plant and animal cell cell structure

Lysosomes are absent in animal cells

  1. Erythrocytes

  2. Plasma cells

  3. Nerve cells

  4. Muscle cells
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • The Red blood cells do not contain lysosomes, mitochondria, nucleus etc.
  • The absence of cellular organelles help them to accommodate maximum space for haemoglobin and helps in carrying more oxygen.
  • It also gives a distinctive bi-concave shape to these cells and also helps in diffusion.
  • So, the correct answer is 'Erythrocytes'.
Multiple choice biology cell structure and micro-organisms animal cell plant and animal cell cell structure

Given below are types of cells present in some animals. Which of the following cells can differentiate to perform different functions?

  1. Choanocytes

  2. Interstitial cells

  3. Gastrodermal cells

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

Interstitial cells are reserve cells which can differentiate into any type of cells. Nematocytes are stinging cells used for offence and defence. Gastrodermal cells line the gastrodermis and intracellular digestion takes place inside these cells. All these cells are found in cnidarians. Choanocytes are found in sponges; they are specialised flagellated cells that line spongocoel and canals.

So, the correct answer is 'Interstitial cells'

Multiple choice biology cell structure and micro-organisms animal cell plant and animal cell cell structure

A scientist was studying the production of a protein that was released by an animal cell into a culture medium. She found that the protein only appeared in the culture medium after she added a few drops of a hormone to the cell. Before adding the hormone, she labelled the protein inside the cell with a fluorescent dye and looked at the cell under the light microscope. The dye was seen in flattered sheets and tube-like structures throughout the cell, and in stacks of flattened sac-like structures. After adding the hormone, the dye was also seen as small dots clustered against the cell membrane. Which statement most likely explains these observations?

  1. The hormone stimulates protein synthesis in the cell vacuole, the protein is then passed to the Golgi apparatus, and eventually passes through the cell membrane by passive diffusion

  2. The hormone triggers the synthesis of the protein in the endoplasmic reticulum and it is then secreted outside of the cell via channel proteins in the cell membrane

  3. The protein is made in the endoplasmic reticulum, is passed to the Golgi apparatus and is secreted through hormone-stimulated exocytosis

  4. The protein is made in the Golgi apparatus is passed to the endoplasmic reticulum and is secreted through hormone-stimulated pinocytosis
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Hormones bring about their characteristic effects on target cells by modifying cellular activities. The given experiment shows that the hormone is a releasing hormone which has increased the secretion of protein product in the target cell.

Multiple choice biology cell structure and micro-organisms animal cell plant and animal cell cell structure

Which of the following is not common in chloroplasts & mitochondria?

  1. Both are present in animal cells

  2. Both contains their own genetic material

  3. Both are present in eukaryotic cells

  4. Both are present in plant cells
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The similarities in chloroplasts and mitochondria are 

1. Both are present and animal cells
2. Both are present in eukaryotic cells and have own genetic material
They are not present in animal cells.
So, the correct option is 'Both are present in animal cells'.

Multiple choice biology cell structure and micro-organisms animal cell plant and animal cell cell structure

Which of the following is a type of intercellular junction between animal cells?

  1. Middle lamella

  2. Plasmodesma

  3. Desmosome

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

Desmosomes are circular regions where adjacent membranes possess disc-shaped thickening on the inner side, a number of tonofibrils and transmembrane linkers embedded in the dense intercellular material. Desmosomes act as 'spot welds' and keep the cells firmly together. They occur in epithelia subjected to disruption. 

Plasmodesma is protoplasmic bridge amongst plant cell wall which occur in the areas of cell wall pits or pores.
Middle lamella is a layer of cell wall and cell wall is absent in an animal cell.
Therefore, the correct answer is option C.

Multiple choice biology tissues, organs, organ system, organism tissues of animals animal tissues and its type tissues: animal tissues fluid connective tissue

State whether true or false. 

The epidermal layer in plants does not have intercellular spaces. 

  1. True

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

The epidermis is the outermost cellular layer which covers the whole plant structure, i.e., it covers roots, stem, leaves, flowers and fruit. It is composed of a single layer of living cells, although there are exceptions. The epidermis is usually closely packed, without intercellular spaces or chloroplasts.