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 zoology living and non living characteristics of life attributes of living organisms signs of life biology : an introduction living world and classification

The structural unit of a non-living thing is

  1. Electron

  2. Neuron

  3. Cell

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

Electron is a stable sub-atomic particle with a charge of negative electricity, found in all atoms and acting as the primary carrier of electricity in solids. 

Molecule is a group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction. 
Cell is the structural unit of a living being.  
A neuron is an electrically excitable cell that processes and transmits information through electrical and chemical signals. 

Multiple choice zoology living and non living characteristics of life attributes of living organisms signs of life biology : an introduction living world and classification

Both living things and nonliving things are made of 

  1. Cells

  2. Molecules

  3. Tissues

  4. Organs
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Every living being is composed of cells which act as the basic structural unit. these cells are in turn made up of more simpler molecules like amino acids, sugars. And all non- living things are also made up of repetitive sequence or mixing of one or more types of molecules.
Hence the correct option is B.
Multiple choice zoology living and non living characteristics of life attributes of living organisms signs of life biology : an introduction living world and classification

Cellular organization has ______ stages

  1. $3$
  2. $5$
  3. $2$
  4. $4$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The components of the cell and the arrangement of the individual parts within the cell form the cellular organisation. There are five stages which include cell, tissue, organs, organ systems and organisms. The cellular organisation provides the complete about the working model of the cell and its components.

So, the correct option is '5'.

Multiple choice evs transportation in living organisms circulatory system and organs blood and blood vessels circulatory system blood pressure

Which of the following statement is true ?

  1. Vessels are multicellular with narrow lumen

  2. Tracheids are multicellular with narrow lumen

  3. vessels are unicellular with narrow lumen

  4. Tracheids are unicellular with wide lumen
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Vessels are multicellular structures formed by the fusion of several cells, and they have a relatively narrow lumen compared to the overall plant structure, though they are wider than tracheids.

Multiple choice zoology structure of chromosome, cell cycle and cell division structure of dna nucleic acid heredity and inheritance

Which of the following has higher surface area (SA) to volume (V) ratio?

  1. Red blood cell

  2. Nails

  3. DNA

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

Surface area to volume ratio increases as the size of an object decreases. DNA, being a molecular structure, has a significantly higher surface area to volume ratio compared to cellular structures like red blood cells or macroscopic objects like hair and nails.

Multiple choice structure of dna and rna nucleic acids and polynucleotides nucleic acids and protein synthesis molecular biology biology

In eukaryotes basic structural unit made of histone and DNA 

  1. Nucleosome

  2. Nucleolus

  3. Chromosome

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

In eukaryotes DNA is tightly bound to histones which form a DNA protein particles called nucleosome. Each nucleosome contains 2 copies of each $H _{2A},H _{2B}.H _{3}$ and $H _{4}$ histone protein bounded on 146 BP of DNA.Each nucleosome bead is linked to next nucleosome bead by linker DNA.

Multiple choice biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

The factory for synthesis of sugars in autotrophic eukaryotes is

  1. Chloroplast

  2. Mitochondrion

  3. Endoplasmic reticulum

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

Chloroplasts are the cell organelles where photosynthesis occurs. The light reactions occur in thylakoid membranes and dark reactions occur in stroma of chloroplasts. These reactions result in synthesis of sugars (glucose) in chloroplasts.

Multiple choice biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

From the following, an organelle containing chlorophyll is

  1. Chloroplast

  2. Endoplasmic reticulum

  3. Nucleus

  4. Mitochondria
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
A. Chloroplasts are greenish plastids which possess photosynthetic pigments, chlorophylls and carotenoids and take part in the synthesis of food. Chlorophylls contain specialised light-absorbing green pigments, therefore help in photosynthesis.
B. Endoplasmic reticulum is a network of reticulum of tiny structures scattered in cytoplasm and composed of three structures- cisternae, tubules and vesicles.
C. Nucleus is a large organelle controlling all the activities of the eukaryotic cells and consists of nuclear envelope, nucleoplasm, nucleolus and chromatin.
D. Mitochondria are cylindrical double membrane organelles and composed of outer, inner membrane, crista and matrix.
So, the correct answer is 'Chloroplast'.
Multiple choice biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

Which of the following is not characterized as an organelle?

  1. Nucleus

  2. Golgi apparatus

  3. Lysosome

  4. Chlorophyll

  5. Chloroplast
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The eukaryotic cell also possesses several membrane-bound organelles. The cell is composed of the nucleus, Golgi complex, lysosome, chloroplast, mitochondria, etc. Chlorophyll is the coloured pigment inside the chloroplast which is involved in the process of photosynthesis.

Thus, the correct answer is option 'Chlorophyll'.

Multiple choice biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

Which of the following organelle acts as a site for photosynthesis in plants?

  1. Ribosome

  2. Mitochondria

  3. Chloroplast

  4. Endoplasmic reticulum

  5. Golgi apparatus
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The process of photosynthesis takes place in the chloroplasts, using chlorophyll, the green pigment involved in photosynthesis. Chloroplasts absorb sunlight and use it in conjunction with water and carbon dioxide gas to produce food for the plant. Chloroplasts capture light energy from the sun to produce the free energy stored in ATP and NADPH through a process called photosynthesis.

Multiple choice biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

Thylakoids occur inside

  1. Mitochondria

  2. Chloroplasts

  3. Golgi apparatus

  4. Endoplasmic reticulum
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • Thylakoid (internal photosynthetic membranes) is a membrane-bound compartment present within the cellular organelle called chloroplast, they are also present in cyanobacteria.
  • It is a site for the light-dependent reactions of photosynthesis. 
  • It is made up of a thylakoid membrane which surrounds the thylakoid lumen.
  • So, the correct answer is 'Chloroplasts'.
Multiple choice biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

Number of membranes separating intrathylakoid space from cytoplasm is

  1. 4

  2. 3

  3. 2

  4. 1
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The chloroplasts are double membrane-bound organelle that is found in the cytoplasm. They have membrane-bound thylakoids in which the photosynthesis takes place. The cytoplasm is thus separated from the intrathylakoid space by 3 membranes. i.e the 2 membranes of the chloroplast, and some membrane of thylakoid.

So, the correct option is '3'

Multiple choice biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

Grana are

  1. Protein storing plastids

  2. Coloured plastids

  3. Stacks of thylakoids

  4. Individual thylakoids present in stroma
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • A stack of thylakoid discs is organized to form grana.
  • A thylakoid refers to the membrane-bound internal compartment within the chloroplasts of a plant cell and cyanobacteria.
  • It is a site for light-dependent reactions of photosynthesis. 
  • There are about  10 to 100 thylakoid discs within a granum and about 40- 60 grana in a plant cell.
  • So, the correct answer is 'Stacks of thylakoids'.
Multiple choice biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

Structure associated with chloroplast of green algae is

  1. Pyrenoid

  2. Stigma

  3. Both A and B

  4. Endoplasmic reticulum
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • The structure associated with chloroplast of green algae is pyrenoid and stigma.
  • Pyrenoid refers to the cellular microcompartments present within the chloroplasts of the cell of green algae and is a major component of the algal carbon concentrating mechanism.
  • Stigma or eyespot is part of a chloroplast which is found in the motile cells of green algae and helps in finding optimal light conditions for photosynthesis.
  • So, the correct answer is 'Both A and B'.