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 evs the muscular system and digestive system in human beings human muscular system closer look into muscular system muscles and its types

Which of the following type of cell junction make up an intercalated disc?

  1. Fascia adherens

  2. Desmosomes

  3. Gap junctions

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

Cardiac cells are connected to each other by intercalated discs. Cardiac muscle cells have three distinct types of intercellular junctions, namely gap junctions, desmosomes, and fascia adherens. All these junctions are located in the intercalated disc.  Hence, all these cell junction make up an intercalated disc of cardiac cells. 

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

Multiple choice botany plant tissues - internal morphology and anatomy theories of meristematic cell development theories of shoot apical meristem development shoot and root apex

Cells of quiescent centre are characterized by

  1. Dense cytoplasm and prominent nuclei

  2. Light cytoplasm and small nuclei

  3. Dividing regularly to add to the corpus

  4. Dividing regularly to add to tunica
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • The quiescent centre is that part of the root-promeristems that contains the initials of epidermis, cortex and stele.
  • These cells divide less frequently as they are inactive and are present at the pole of cortex and stele.
  • The cells with QC have small dictyosomes, nuclei and nucleoli with little cytoplasm.
  • These cells also have little endoplasmic reticulum, mitochondria and contain low concentrations of RNA, DNA and protein than the other cells of the root apex.
  • So, the correct answer is 'Light cytoplasm and small nuclei'.
Multiple choice botany plant tissues - internal morphology and anatomy theories of meristematic cell development theories of shoot apical meristem development shoot and root apex

Histogen tissues are classified on the basis of _________.

  1. Plane of division

  2. Type of cells they form

  3. Position

  4. Origin
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • The shoot apical meristem (SAM) form three distinct meristematic zones called the histogens.
  • These histogens are present at the growing tips of a stem or a root.
  • These tips consist of three histogens based on the type of cells they form.
  • Each of these histogens gives rise to tissues which are different from one another- dermatogen, periblem, plerome (principle tissues)
  • The dermatogen or the outer layer gives rise to the epidermis, periblem or middle layer gives rise to the cortex as well as the endodermis, plerome or the inner layer gives rise to vascular tissues.
  • This is called histogen theory which was proposed by Hanstein in 1870.
  • So, the correct answer is 'Type of cells they form'
Multiple choice biology anatomy of flowering plants theories of meristematic cell development theories of shoot apical meristem development shoot and root apex
The cells of the quiescent centre are characterised by

  1. having dense cytoplasm and prominent nuclei

  2. having light cytoplasm and small nuclei

  3. dividing regularly to add to the corpus

  4. dividing regularly to add to tunica
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The cells of the quiescent centre are characterised by 'light cytoplasm and small nuclei'.

Multiple choice biology selection and evolution theory of natural selection natural selection evidence for evolution

The endosymbiont theory explains all of the following except

  1. The similar size that mitochondria and chloroplasts share

  2. The presence of ribosomes in mitochondria

  3. The presence of mitochondrial DNA (mtDNA)

  4. The presence of a membrane composed of a lipid bilayer in chloroplasts

  5. The presence of membrane proteins on prokaryote cell membrane
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation
Endosymbiotic theory is a evolutionary theory which explains how eukaryotic cells evolved from prokaryotic organisms.
Evidences of endosymbiotic theory are:
1. Mitochondria and chloroplasts are double membrane bound cell organelles. The inner membrane probably evolved from the plasma membrane of engulfed bacterium and outer membrane from the plasma membrane or endoplasmic reticulum of the host cell.
2. Almost similar size of mitochondria and chloroplast and bacteria and their ribosomes.
3. Cristae of mitochondria resemble the folded membranes is groups of bacteria.
4. Mitochondrion and chloroplast both have circular DNA similar to those of bacterial DNA.
Hence, endosymbiotic theory doesn't explain the presence of membrane proteins on prokaryote cell membrane.
So, the correct answer is 'The presence of membrane proteins on prokaryote cell membrane'.
Multiple choice biology structural organization in living organisms structure of a plant cell levels of organisation in plants plant and animal cell

The barrier between protoplasm and other environment in a plant cell is 

  1. Cell wall

  2. Nuclear membrane

  3. Tonoplast

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

In the plant cell, plasma membrane and cell wall both are present, both act as a barrier between protoplasm and the outer environment.

Nuclear membrane act as a barrier between nucleoplasm and cytoplasm.
Tonoplast is the membrane of the vacuole and acts as the barrier between the vacuole sap and the protoplasm of the cell. In animal cell plasma membrane act as the barrier between protoplasm and the environment. Because animal cell lack the cell wall.
So, the correct answer is ' Cell wall & plasma membrane '

Multiple choice biology structural organization in living organisms structure of a plant cell levels of organisation in plants plant and animal cell

A plant cell has

  1. Cell wall

  2. A number of small vacuoles

  3. A few large vacuoles

  4. A single central vacuole

  5. Both A and D
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

  • A plant cell has a cell wall and single central vacuole.
  • Plant cells are eukaryotic cells that differ in several key aspects from the cells of other eukaryotic organisms. 
  • Their distinctive features include:
  • A large central vacuole
  • A cell wall composed of cellulose and hemicellulose
  • Specialized cell-to-cell communication pathways known as plasmodesmata
Plastids

Multiple choice biology structural organization in living organisms structure of a plant cell levels of organisation in plants plant and animal cell

Growth of cell wall during cell elongation takes place by 

  1. Apposition

  2. Intussusception

  3. Both A and B

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

Plant cell is covered by a cellulosic cell wall. The cell wall is dead at maturity but grows when immature to permit cell elongation. Intussusception is growth by deposition of new materials between existing components of cell walls. Cell elongation occurs through intussusception. In apposition, new wall layers are laid. Growth of wall in new cells occurs through apposition.

Multiple choice biology structural organization in living organisms structure of a plant cell levels of organisation in plants plant and animal cell

Cell wall of plant cells is formed of 

  1. Cellulose

  2. Hemicellulose

  3. Proteins

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

The cell wall is a protective outer covering of the cell. It is mostly present in plant cells. It is not present in the animal cell. It supports the contents of the cell and protects from pathogen attack and wear and tear. It is made of cellulose. Cellulose is a natural polymer made of smaller sugar units. It gives remarkable strength to the wood. 

Multiple choice biology structural organization in living organisms structure of a plant cell levels of organisation in plants plant and animal cell

Which of the following is absent in a plant cell?

  1. Centrosome

  2. Lysosomes

  3. Both A and B

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
The centrosome is a microtubule-organizing centre. It is found near the nuclei of animal cells. Animal cells have another set of organelles which are not found in plant cells. These are lysosomes. The lysosomes are the cell's "garbage disposal." 
Multiple choice biology structural organization in living organisms structure of a plant cell levels of organisation in plants plant and animal cell

Animal cells do not have 

  1. Plastid

  2. Chloroplast

  3. Cell wall

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

Plant and animal cells have several differences and similarities. For example, animal cells do not have a cell wall or chloroplasts but plant cells do. Animal cells are round and irregular in shape while plant cells have fixed, rectangular shapes.

Multiple choice biology structural organization in living organisms structure of a plant cell levels of organisation in plants plant and animal cell

Which of the following statements is true about the plant cell?

  1. The cytoplasm is filled up with nucleus

  2. The cytoplasm is a jelly-like mixture of cellulose

  3. Plant cells contain a rigid cell wall made up of cellulose

  4. There are plenty of chloroplast granules in plant root cells
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Cellulose forms an integral part of the cell wall which provides strength and rigidity to the cell. It helps to maintain the structural integrity of a particular cell. Cellulose is a complex polysaccharide which is made up of β(1→4) linked D-glucose units.

Thus, the correct answer is option C. 

Multiple choice biology structural organization in living organisms structure of a plant cell levels of organisation in plants plant and animal cell

Which of the following statements is true about the plant cell?

  1. The cytoplasm is filled up with nucleus.

  2. The cytoplasm is a jelly-like mixture of cellulose.

  3. Plant cells contain a rigid cell wall made up of cellulose.

  4. There are plenty of chloroplast granules in plant root cells.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Cellulose forms an integral part of the cell wall which provides strength and rigidity to the cell. It helps to maintain the structural integrity of a particular cell. Cellulose is a complex polysaccharide which is made up of β(1→4) linked D-glucose units.

Thus, the correct answer is option C. 

Multiple choice biology structural organization in living organisms structure of a plant cell levels of organisation in plants plant and animal cell

Which of the following is correct in plant cell?

  1. Bigger vacuole with rigid cell wall.

  2. Centriole takes part in cell division.

  3. Centrosome are inactive in non-dividing cell.

  4. Absence of cell membrane.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Vacuoles are found in almost all the cells. A plant cell usually has a large central sap vacuole. Most mature plant cells have one large vacuole that typically occupies more than 30% of the cell's volume, and that can occupy as much as 80% of the volume for certain cell types and conditions. Another important characteristic of a plant cell is the presence of a cellulosic cell wall. The plant cell wall is dead at maturity and is rigid. Hence, cell wall provides support and maintains the shape of a plant cell.