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 bio-chemistry structure and function of cell organelles microbodies living organisms and energy production single membrane bound organelles

What is degraded by peroxisomes?

  1. Carbon dioxide

  2. Hydrogen peroxide

  3. Lithium oxide

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

Peroxisomes are microbodies which have enzymes for peroxide metabolism. They include : (a) Peroxide producing oxidative enzymes like peroxidase, urate oxidase or uricase, amino acid oxidase and (b) peroxide destroying enzymes like catalase.
Peroxisomes occur widely in animals cells, protists, fungi, higher plants but quite common in photosynthetic cells. In mesophyll cells, peroxisomes interact with chloroplasts, and mitochondria to take part in photorespiration.

Multiple choice bio-chemistry structure and function of cell organelles microbodies living organisms and energy production single membrane bound organelles

DNA remains absent in

  1. Chloroplast

  2. Nucleus

  3. Peroxisomes

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

Peroxisomes are microbodies which have enzymes for peroxide metabolism. They include :

(a) Peroxide producing oxidative enzymes like peroxidase, urate oxidase or uricase, amino acid oxidase and (b) Peroxide destroying enzymes like catalase. 
Peroxisomes do not have DNA. DNA is present in nucleus and some cell organelles like chloroplast and mitochondria.

Multiple choice bio-chemistry structure and function of cell organelles microbodies living organisms and energy production single membrane bound organelles

Microbodies are minute vesicles and are present in

  1. Plant cells only

  2. Animal cells only

  3. Prokaryotic cells only

  4. Both plant and animal cells
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Microbodies are a type of organelles that are found in both plant and animal cells. The organelles in the microbody family include peroxisomes, glyoxysomes, glycosomes and hydrogenosomes. In vertebrates, microbodies are especially prevalent in the liver and kidney organs.
So, the correct answer is 'Both plant and animal cells'.
Multiple choice bio-chemistry structure and function of cell organelles microbodies living organisms and energy production single membrane bound organelles

Glyoxysomes are useful in

  1. Converting sugars to fats

  2. Converting fats to sugars

  3. Deamination and converting amino acids to fatty acids

  4. Amination and changing fatty acids to amino acids
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • Glyoxysomes are a type of peroxisomes found in plants and few filamentous fungi.
  • They are particularly found in fat storage tissues of germinating seeds (peanuts, soybeans etc.) in plants.
  • It helps in fatty acid oxidation, glyoxylate cycle and gluconeogenesis.
  • They contain enzymes (citrate synthase, isocitrate lyase and malate synthase etc.) which are responsible for beta-oxidation of fatty.
  • It also contains enzymes which produce intermediate products for the synthesis of sugars by gluconeogenesis.
  • So, the correct answer is 'Converting fats to sugars'.
Multiple choice bio-chemistry structure and function of cell organelles microbodies living organisms and energy production single membrane bound organelles

Some of the enzymes, which are associated in converting fats into carbohydrates, are present in

  1. Liposomes

  2. Golgi bodies

  3. Microsome

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

Glyoxysomes are microbodies which occur only in fat rich plant cell, where they take part in $\beta$-oxidation of fats and perform glyoxylate cycle. Glyoxysomes also possess catalase enzyme. In fat storing plant cells, first fats are converted to carbohydrates which are then metabolised.

Multiple choice bio-chemistry structure and function of cell organelles microbodies living organisms and energy production single membrane bound organelles

In 1967, R. W. Breidenbach and H. Beevers discovered microbodies in fat storing cells of germinating seed known as

  1. Lomasomes

  2. Mesosomes

  3. Peroxisomes

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

Glyoxysomes were discovered by Breidenbach, 1967 and Beevers, 1963. Glyoxysomes are microbodies which occur only in fat rich plant cells where they take part in $\beta$-oxidation of fats and perform glycolate cycle. Glyoxysomes possess catalase enzyme.

Multiple choice bio-chemistry structure and function of cell organelles microbodies living organisms and energy production single membrane bound organelles

The following can be called as plant lysosomes.

  1. Spherosomes

  2. Aleurone grains

  3. Vacuoles

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

Spherosomes are single half unit membrane covered small spherical organs which synthesize and store fats. They develop from endoplasmic reticulum. In some plants, spherosomes have lysosomal activity, e.g., spherosomes found in maize root tip.

Multiple choice bio-chemistry structure and function of cell organelles microbodies living organisms and energy production single membrane bound organelles

Unique to lysosomes in comparison to peroxisomes is that

  1. Peroxisomes lack lytic enzymes.

  2. Lysosomal membranes show latency which peroxisome lack.

  3. Peroxisomes cannot be found in animal tissue.

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

Peroxisomes are microbodies which have enzymes for peroxide biosynthesis. They include peroxide producing enzymes like peroxidase, urate oxidase, amino acid oxidase and peroxide destroying enzyme catalase. Lysosomes are small vesicles containing hydrolysing enzymes and surrounded by single membrane. They are formed by Golgi apparatus and contain some 60 different types of hydrolytic enzymes eg nucleases, proteases, lipases, phosphatases etc. for digestion of various materials.

Multiple choice bio-chemistry structure and function of cell organelles microbodies living organisms and energy production single membrane bound organelles

Match the following.

Column I Column II
Microbody Function
I) Sphaerosomes a) $H _2O _2\rightarrow H _2O^+$ oxygen
II) Peroxisomes b) acts like elaioplasts
III) Glyoxysomes c) Helps in yolk formation
IV) Lomasomes d) Cell-elongation
V) Transosomes e) Fats $\rightarrow$ Carbohydrates
f) Radiant energy $\rightarrow$ Chemical energy

  1. I-a, II-b, III-d, IV-c, V-e

  2. I-b, II-c, III-a, IV-d, V-f

  3. I-b, II-a, III-e, IV-d, V-c

  4. I-c, II-a, III-b, IV-d, V-e
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Matching: I-b (Sphaerosomes store fats/elaioplasts), II-a (Peroxisomes handle H2O2), III-e (Glyoxysomes convert fats to carbohydrates), IV-d (Lomasomes involved in cell wall/elongation), V-c (Transosomes involved in yolk formation). Option A matches these correctly.

Multiple choice bio-chemistry structure and function of cell organelles microbodies living organisms and energy production single membrane bound organelles

Animal cell is different from plant cell in lacking 

  1. CaCO$ _3$ crystals in cytoplasm

  2. Sphaerosomes

  3. Pyrenoids and chloroplast

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

Cell Inclusions are non-living substances in plant cells. They are of four categories - reserve food, excretory material, pigment and minerals. Due to their presence, a cell may become different from other surrounding cells. It is then called as an idioblast. Calcium carbonate occurs as a mass of crystals around a cellulose core to form cystolith e.g., leaf hypodermis of Banyan tree. Spherosomes are single half unit membrane covered small organelles in plants which synthesize and store fats. They develop from ER. In some plants, spherosomes have lysosomal activity. e.g., maize root tip. Chloroplasts are green plastids which take part in photosynthesis and temporary or permanent storage of starch. Pyrenoids are food storage bodies within the chloroplasts. All of the above mentioned structures are not found in an animal cell.

Multiple choice bio-chemistry structure and function of cell organelles microbodies living organisms and energy production single membrane bound organelles

F$ _1$ subunit of oxysome is called as

  1. Head

  2. Lineage

  3. Base

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

Oxysomes are the structures which are present on the surface of the folded inner membrane of the mitochondria. They are also called f0-f1 particles or ATP synthase. They play the most important role in the formation of energy for the functioning of the cell. The F1 subunit of the oxysomes is refered as the head.

Multiple choice bio-chemistry structure and function of cell organelles microbodies living organisms and energy production single membrane bound organelles

Liposomes in plants are also called as

  1. Spherosomes

  2. Glyoxysomes

  3. Lysosomes

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

Spherosomes are single half unit membrane covered small spherical organelles (0.5 to 1.0 micrometer) which synthesize and store fats. Hence, spherosomes are also called as liposomes. Liposome term specifically means vesicles having fat or fat droplets. Spherosomes develop from endoplasmic reticulum. In some plants, spherosomes have lysosomal activity, e.g., maize root tip.

Multiple choice bio-chemistry structure and function of cell organelles microbodies living organisms and energy production single membrane bound organelles

Which of the following organelles is surrounded by a single membrane ?

  1. Mitochondria

  2. chloroplast

  3. Peroxisomes

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

Peroxisomes are single membrane bounded organelles found in nearly all eukaryotic cells. Rest of three are Double membrane.

So, the correct answer is 'peroxisomes'

Multiple choice bio-chemistry structure and function of cell organelles microbodies living organisms and energy production single membrane bound organelles

Peroxisomes have which of the following enzymes?

  1. Hydrolases

  2. Oxidases

  3. Transferases

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

Peroxisomes are microbodies which have enzymes for peroxide biosynthesis. They include peroxide producing oxidative enzymes like peroxidase, urate oxidase or uricase (hence, peroxisomes are also called as uricosome), amino acid oxidase and peroxide destroying enzymes catalase. Peroxisomes occur widely in animal cells, protists, fungi, eukaryotic algae, bryophytes, pteridophytes and higher plants.