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 bio-chemistry cell-the basic unit of life introduction to cell discovery and cell theory cell discovery cell discovery and cell theory cell as structural and functional unit

The theory proposing that body of an organism consists of incompletely divided cells is known as

  1. Organismal theory.

  2. Protoplasmic theory.

  3. Cell theory.

  4. Theory of cell lineage.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The organismal theory posits that the body of an organism is a single continuous unit (a protoplasmic mass) that is incompletely divided into cells, rather than being a collection of independent cells.

Multiple choice bio-chemistry cell-the basic unit of life introduction to cell discovery and cell theory cell discovery cell discovery and cell theory cell as structural and functional unit

Which is correct about cell theory in view of current status of our knowledge about the cell structure?

  1. It needs modification due to discovery of subcellular structure like chloroplasts and mitochondria.

  2. Modified cell theory means that all living beings are composed of cells capable of reproducing.

  3. Cell theory does not hold good because all living beings (e.g., viruses) do not have cellular organisation.

  4. Cell theory means that all living objects consist of cells whether or not capable of reproducing.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Modern cell theory acknowledges that viruses, which lack cellular organization, are living entities, thereby challenging the original premise that all living beings must be composed of cells.

Multiple choice bio-chemistry cell-the basic unit of life introduction to cell discovery and cell theory cell discovery cell discovery and cell theory cell as structural and functional unit

The size of the cells of an organism has no relation with the size of its body.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • A cell is the smallest form containing genetic material, cell organelles, cytoplasm and it can replicate to give rise to new cells. The cell size is the same in the elephant and in ant. 
Multiple choice bio-chemistry cell-the basic unit of life introduction to cell discovery and cell theory cell discovery cell discovery and cell theory cell as structural and functional unit

Cells are autonomous because___________________

  1. They synthesize components of living protoplasm from non-living materials.

  2. They are able to grow and divide.

  3. Each cell has its own life span.

  4. All of the above.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • All of the living organisms are made up of cells. Cells can give rise to new cells by cell division. Each cell has a particular life span. Cells possess machinery, enzymes to form living protoplasm from non-living materials. 
  • For example, plant cells take up CO$ _2$ and O$ _2$ from the environment and make food in the presence of sunlight. Animal cells break down or oxidize glucose and form ATP. 
  • Such ATPs are used as energy currency in cell and various processes of cell formation organelle are carried out. Thus, the correct answer is option D.
Multiple choice bio-chemistry cell-the basic unit of life introduction to cell discovery and cell theory cell discovery cell discovery and cell theory cell as structural and functional unit
Robert Hooke actually observed .......... of cells. 

  1. Cell walls.

  2. Protoplasts.

  3. Wall-less cells.

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

Robert Hook discovered cells in 1655 with the help of compound microscope. He was observing insects, sand, bird feathers, fossils and plants. Once he was observing a thin slice of cork under the microscope he found a framework similar to honeycomb-like structure. He named those structures as cells but those were actually non living cell walls. So option A is correct.

Multiple choice bio-chemistry carbohydrate metabolism energy output living organisms and energy production respiration in cell

The organelle responsible for ATP formation is  

  1. Quantasome

  2. Thylakoid

  3. Chondriosome

  4. Mitochondria
Reveal answer Fill a bubble to check yourself
C,D Correct answer
Explanation
 Name of the organelle  Function
 Quantasome  These are the particles found in the membrane of thylakoid and in which process of photosynthesis takes place.
 Thylakoid  Carry out the light reactions of photosynthesis
 Chondriosome Another name of a mitochondrion. Responsible for ATP formation
 MItochondria The two stages of respiration take place in the mitochondria. Krebs cycle occurs in the cristae of the mitochondria. Oxidative phosphorylation occurs on the membranes. The energy is released at the end of respiration in the form of ATP.

So, the correct answer is ' Mitochondria and Chondriosome '

Multiple choice biology digestion and absorption minerals and vitamins nutrition and diet role of various nutrients

In Amoeba, absorption of the digested nutrients occurs in

  1. Contractile vacuole

  2. Plasma membrane

  3. Cytoplasm

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

The digested food present in the food vacuole of amoeba is absorbed directly into the cytoplasm of amoeba cell by diffusion. Since, amoeba consists of only one small cell, it does not require blood system to carry the digested food. The digested food just spreads out from the food vacuole into the whole of amoeba cell. After absorption of food, the food vacuole disappears.

Therefore, the correct answer is option C.

Multiple choice biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

Which of the following is main enzyme of plasma membrane?

  1. TPPase

  2. ATPase

  3. Peptidyl transferase

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

ATPase are a class of enzymes that catalyze the dephosphorylation of ATP into ADP and a free phosphate ion. This dephosphorylation reaction releases energy, which the enzyme harnesses to drive other chemical reactions that would not otherwise occur. This process is widely used in all known forms of life. Such enzymes are integral membrane proteins anchored within biological membranes (plasma membrane), and move solutes across the membrane, typically against their concentration gradient.

Multiple choice biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

Peptidyl transferase enzyme found on 

  1. Cytoplasm

  2. E.R

  3. Golgi body

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

The peptidyl transferase is an aminoacyltransferase, it performs the primary enzymatic function of the ribosome, which forms peptide bonds between adjacent amino acids using tRNAs during the translation process of protein biosynthesis. Peptidyl transferase activity is carried out by the ribosome. Peptidyl transferase activity is not mediated by any ribosomal proteins but by ribosomal RNA (rRNA), a ribozyme. 

Multiple choice biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

Class of enzymes contained in lysosome

  1. Lyases

  2. Ligases

  3. Hydrolases

  4. Transferases
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Lysosomes are formed by Golgi bodies. These are membrane-bounded vesicles which contain digestive and hydrolase enzymes like glycosidases, proteases, nucleases, phospholipases, and sulfatases. The enzymes are synthesized in the mRNA transcripts exit the nucleus into the cytosol, where they are translated by rough endoplasmic reticulum. The enzymes leave the Golgi apparatus as a vesicle known as lysosomes. 
So, the correct answer is option C.
Multiple choice biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

Class of enzymes contained in lysosomes is 

  1. Lyases

  2. Ligases

  3. Hydrolases

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

A lysosome is a membrane-bound organelle found in nearly all animal cells. They are spherical vesicles which contain hydrolytic enzymes that can break down many kinds of biomolecules. So, the correct answer is option C.

Multiple choice classification of pteridophytes kingdom plantae plant kingdom biology

The neck of the archegonium in Selaginella is made of

  1. Four rows of cells with several cells in each row

  2. Two tiers of four cells each

  3. Four tiers of two cells each

  4. Six rows of cells
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The neck of the archegonium in Selaginella is very short, consisting of two tiers of four cells each.

Multiple choice botany cell structure and organization membrane bound organelles cell: size and differentiation microscopy

Outermost layer surrounding the vacuole is 

  1. Tonoplast

  2. Vacuolar Membrane

  3. Both A and B

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

A vacuole is the double membrane bound structure. The outermost covering of vacuole is called as tonoplast or vacuolar membrane. The tonoplast is the cytoplasmic membrane separating the vacuolar contents from the cell's cytoplasm. Therefore, the correct answer is option C.