Biology · Science General

Cell Biology and Structure

3,221 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 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'.
Multiple choice biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

Quantasomes occur in

  1. Stroma

  2. Grana/chloroplast

  3. Golgi body

  4. Mitochondria
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • Quantasomes occur in the Grana/chloroplast.
  • Quantasomes can be defined as small particles found in the thylakoid membrane of the chloroplasts.
  • These particles are embedded in a paracrystalline form on the surface of thylakoid discs in chloroplasts.
  • So, the correct answer is 'Grana/chloroplast'.
Multiple choice biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

Stroma is the ground matrix of

  1. Lysosomes

  2. Oxysomes

  3. Ribosomes

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

Stroma, refers to the colourless fluid surrounding the grana within the chloroplast. Within the stroma are grana, stacks of thylakoids, the sub-organelles, where photosynthesis is commenced before the chemical changes are completed in the stroma. The internal space enclosed by the chloroplast double membrane but excluding the thylakoid space. This space, filled with a colorless hydrophilic matrix, contains DNA, ribosomes and some temporary products of photosynthesis also known as chloroplastic stroma.

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

Cytochrome $b _6$ and cytochrome f occur in

  1. Ribosomes

  2. Mitochondria

  3. Chloroplasts

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

The cytochrome b6f complex is an enzyme found in the thylakoid membrane in the chloroplast of plants, cyanobacteria, and green algae, that catalyzes the transfer of electrons from plastoquinol to plastocyanin.


So, the correct option is 'Chloroplast'.

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

Ground substance of chloroplast is

  1. Stoma

  2. Stroma

  3. Granum

  4. Cisterna.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Chloroplast is a double membrane structure which is only present in plants . Chloroplast has fluid which is called stroma it is responsible for dark reaction . There are sac like structure present in it which are called thylakoids which which help in light reaction.

So, the correct option is 'Stroma'.
Multiple choice biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

Quantasomes occur on the surface of

  1. Cristae

  2. Plasmalemma

  3. Nuclear envelope

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

Quantasomes are composed of lipids and proteins that include various photosynthetic pigments and redox carriers. These are the particles found in the thylakoid membrane of chloroplasts in which photosynthesis takes place. They are embedded in a paracrystalline array on the surface of thylakoid discs in chloroplasts.

So, the correct option is 'Thylakoids'.

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

The individual flattened stacks of membranous structures inside the chloroplasts are known as:

  1. Grana

  2. Stroma

  3. Thylakoids

  4. Cristae
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
A thylakoid is a membrane-bound compartment inside chloroplasts. They are the site of the light-dependent reactions of photosynthesis. Thylakoids consist of a thylakoid membrane surrounding a thylakoid lumen. Chloroplast thylakoids frequently form stacks of disks referred to as grana. So the correct option is ' Thylakoid'

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

Read the given statements A & B and choose the correct option.
A. The ribosomes of the chloroplasts are smaller than the cytoplasmic ribosomes.
B. Chloroplasts can synthesise some of their proteins but they receive other proteins from cytoplasm.

  1. Only statement A is correct.

  2. Only statement B is correct.

  3. Both statements are correct.

  4. Both statements are incorrect.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A. Chloroplast ribosomes are similar to those found in the prokaryotes that is 70s type. Eukaryotic ribosomes which are found in the cytoplasm are of 80stype.

B. Most chloroplast and mitochondrial proteins, however, are synthesized outside the organelle on cytosolic ribosomes that are not bound to the rough endoplasmic reticulum.
So the correct option is 'Only statement A is correct'.

Multiple choice biology diversity in living world characteristics of vertebrates classification of vertebrata classifications of chordata

Humans fall into which kingdom Animalia category?

  1. Hemichordata

  2. Mollusca

  3. Chordata

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

Humans are categorized as vertebrates in the phylum Chordata. The phylum Chordata contains all animals that possess, at some point during their lives, a hollow nerve cord, and a notochord, a flexible rod between the nerve cord and the digestive track. The phylum Chordata is an extremely diverse phylum and the one most recognizable to us. 

So, the correct answer is option C.

Multiple choice biology biodiversity and classification monera five kingdoms of living organisms biodiversity and need of classification

Golgi apparatus does not occur in

  1. Yeast

  2. Liver cells

  3. Higher plants

  4. Bacteria and blue green algae
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Prokaryotes are unicellular organisms. They lack membrane-bound organelles like mitochondria, golgi apparatus. They also lack true nucleus. Instead, they have nucleoid or incipient nucleus. Nucleoid is an undifferetiated, unorganised, fibrillar nucleus without any limiting membrane. They have ribosomes in the cytoplasm. Examples include bacteria like E. coli, blue green algae. 

Thus, the correct answer is 'Bacteria and blue green algae.'

Multiple choice biology biodiversity and classification monera five kingdoms of living organisms biodiversity and need of classification

The organelles found in 4 different types of cells are shown in the table below. Use the information in the table to answer the next 3 questions.
Cell Types and Their Characteristics

Cell Type Nucleus Mitochondria Cell Wall  Cell Membrane Chloroplast
1234 yesyesyes no yesyesyesno noyesyesyes yesyesyesyes noyes nono

Which cell type is prokaryotic?

  1. Cell 1 and 2 only

  2. Cell 3 only

  3. Cell 4 only

  4. Cell 2 and 3 only

  5. Cell 3 and 4 only
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
A prokaryotic cell doesn't have well defined nucleus and membrane bound cell organelles but cell wall and cell membrane are present.
From the information given in the question, it is clear that cell 4 doesn't have a nucleus and the membrane bound cell organelles, mitochondria and chloroplast but it has cell wall and cell membrane.
So, the correct answer is 'Cell 4 only'.
Multiple choice biology tissues, organs, organ system, organism defense mechanism in plants epidermal tissue system permanent tissues and their types

Epidermal cells are

  1. Guard cells

  2. Root hairs

  3. Trichomes

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

Trichomes or hairs grow out from the epidermis in many species. In root epidermis, epidermal hairs, termed root hairs are common and are specialized for absorption of water and mineral nutrients. Guard Cells are the only epidermal cells that can make sugar. As a result, water from other cells enter the guard cells by osmosis so they swell and become turgid. 

So, the correct answer is 'All the above.'