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 plant and animal tissues nervous system in animals structure of neuron structure and function of neuron

Which cell organelle is absent in neuron?

  1. Mitochondria

  2. Ribsomes

  3. Centrioles

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

A centriole is a small set of microtubules arranged in a specific way. There are nine groups of microtubules. When two centrioles are found next to each other, they are usually at right angles. The centrioles are found in pairs and move towards the poles (opposite ends) of the nucleus when it is time for cell division. Neurons cannot divide because they lack centrioles.
Because centrioles function in cell division, the fact that neurons lack these organelles is consistent with the amitotic nature of the cell.

Therefore, the correct answer is option C.

Multiple choice biology plant and animal tissues nervous system in animals structure of neuron structure and function of neuron

Which of the following tissues in mammals show least capacity for regeneration?

  1. Blood

  2. Bone

  3. Nerve

  4. Cartilage
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • The different cells in the body can regenerate in order to replace the damaged or the worn-out cells. 
  • The neurons are one of the brain cells. The cells divide during the embryonal stage. After the birth of a child, the cells lose their capacity to divide. 
  • These cells have the least capacity of regeneration. 
  • Thus, the correct answer is option C. 
Multiple choice biology plant and animal tissues nervous system in animals structure of neuron structure and function of neuron

Choose the odd pair.

  1. Areolar connective tissue - Collagen

  2. Epithelium - Keratin

  3. Muscle fibre - Actin

  4. Neuron - Melanin
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Areolar tissue contains collagen, epithelium contains keratin, and muscle fibers contain actin. Melanin is a pigment found in skin and hair, not a structural protein characteristic of neurons.

Multiple choice biology plant and animal tissues nervous system in animals structure of neuron structure and function of neuron

Some cell in our body can be over a feet long. They are

  1. Muscle cells

  2. Bone cells

  3. Nerve cells

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

Certain neurons or nerve cells may almost equal the length of body itself. The axon of a motor neuron in the spinal cord, that innervates a muscle in the foot can be about 1 meter (3 feet) in length.

Multiple choice biology human health and disease drug, tobacco and alcohol consumption addiction and dependence community health and hygiene

Which cell organelle plays an important role in detroxification of many poisons and drugs in a cell ?

  1. mitochondria

  2. vacuoles

  3. Iysosomes

  4. smooth endoplasmic reticulum
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The endoplasmic reticulum functions as a cytoplasmic framework providing a surface for some of the biochemical activities of the for some of the biochemical activities of the cell. In the liver cells of vertegrates, smooth endoplasmic reticulum (SEF) plsys a crucial role in detoxifying many poisons and drugs.

Multiple choice botany internal structure of root, stem and leaf internal structure of dicot stem internal structure of stem(dicot and monocot) anatomy of stem

Casparian strips occur in

  1. Radial walls of endodermis

  2. Radial walls of phellem cells

  3. Radial walls of epidermal cells

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

Casparian strips occur in radial walls of endodermis. The Casparian strip is a band of cell wall material deposited on the radial and transverse walls of the endodermis, and is chemically different from the rest of the cell wall - the cell wall being made of lignin and without suberin - whereas, the Casparian strip is made of suberin and sometimes lignin. It blocks the passive flow of materials such as water and solutes into the stele of a plant.
Thus, the correct answer is option A.

Multiple choice biology life processes: control and coordination control and coordination in plants growth in plants chemical coordination in plants animal senses sense organs in animals sense organs in humans

Choose the correct answer from the alternatives given.
The mitotically active and hormone producing cells are:

  1. xylem

  2. meristem

  3. phloem

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

Meristem is the actively dividing cells at the root and shoots apices that are mitotically active.

So, the correct option is 'meristem'.

Multiple choice botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

Mesosomes were taken as

  1. Golgi bodies

  2. Plastids

  3. Mitochondria

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

In the vesicle of mesosomes, the respiratory enzymes and the components of electron transport such as ATPase, dehydrogenase, cytochrome are present in low amount. So, they were considered anologous to mitochondria for their respiratory function. 

So, the correct option is 'Mitochondria'.

Multiple choice botany living world and classification of microbes gram staining microbiology: organisms in industry cell wall and cell membrane

The main difference between Gram +ve and Gram -ve resides in the composition of 

  1. Cilia

  2. Cell wall

  3. Cell membrane

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

The Gram-negative cell wall is characterized by presence of outer membrane, a thinner peptidoglycan layer and extensive periplasmic space surrounding the peptidoglycan. The uppermost layer of the outer membrane has lipopolysaccharide, while the innermost layer is a typical lipid layer. Presence of membrane channels formed by porin proteins in outer membrane impart make them less penetrable as compared to Gram positive cells. Gram positive cells are characterized by presence of single thick layer of cell wall which is made up of peptidogycan, teichoic acid and lipoteichoic acid. They lack outer membrane and porin and have narrow periplasmic space. Plasma membrane is the unit membrane in both, Gram positive and Gram negative bacteria, present beneath cell wall with primarily phospholipids (making up about 30–40% of the membrane mass) and proteins (60–70%). The dense gelatinous solution surrounded by plasma membrane is cytoplasm which has same composition in both, Gram positive and Gram negative cells. Cilia are the eukaryotic structures which are absent in bacteria as they are prokaryotic. 

Thus, the correct answer is option B.

Multiple choice botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

Cell organelles are the parts of a living cell. All cells have a cell membrane and some cells have a cell wall.
 Which of the following has a cell wall? 
 I. Plants
 II. Bacteria
 III. Fungi

  1. I only

  2. II only

  3. I and II only

  4. II and III only

  5. I, II and III
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation
  • Cell wall is the outermost, rigid, protective, non-living and supportive layer found in plant cells, bacteria, fungi, and some protists but absent in animal cells.

1. Plants cell wall is made up of cellulose, hemicellulose, and pectin. Cellulose is a polymer of glucose and pectin is a polymer of galactouronic acid.

2. Bacterial cell wall is made up of protein lipid polysaccharide NAG (N-Acetyl Glucosamine) and NAM (N-Acetyl Muramic Acid).

3. Fungal cell wall is made up of chitin which is a polymer of glucosamine.
Hence all options are correct.

So, the correct answer is 'I, II and III'.
Multiple choice botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

Cell recognition and adhesion occur due to biochemicals of cell membranes named

  1. Proteins

  2. Lipids

  3. Proteins and lipids

  4. Glycoproteins and glycolipids
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • Cell recognition and adhesion occur due to biochemicals of cell membranes name glycoproteins and glycolipids.
  • Glycocalyx or pericellular matrix is a carbohydrate-enriched coating of glycoprotein and a glycolipid that covers the cell membranes of few bacteria, epithelial cells and other cells. 
  • It is mainly used in the recognition of the cell (distinguish between healthy and diseased cells) and also regulates the endothelial vascular tissues.
  • So, the correct answer is 'Glycoproteins and glycolipids'.