Tag: microbodies

Questions Related to microbodies

In which type of reactions related to plant photosynthesis peroxisomes are involved?

  1. Glycolate cycle

  2. Calvin cycle

  3. Bacterial photosynthesis

  4. Glyoxylate cycle


Correct Option: A
Explanation:

Glycolate cycle, also known as C$ _2$ cycle, is a complex metabolic pathway, that takes place in chloroplasts, mitochondria and peroxisomes of plant cells and is responsible for the formation of the amino acids, serine and glycine from non-phosphorylated intermediates of the carbon reduction cycle of photosynthesis.

Spherosomes have affinity for

  1. Sudan III

  2. Eosin stains

  3. Leishman's stain

  4. Giemsa's stains


Correct Option: A
Explanation:

Sudan stains have high affinity for fats, lipids, triglycerides and lipoprotein. Hence, when a cell is exposed to Sudan stain, it becomes attached to spherosomes because spherosomes are membrane covered small spherical organelles which synthesize and store fats.

Peroxisomes are commonly seen in 

  1. Bundle sheath cells

  2. Vascular bundles

  3. Mesophyll cells

  4. Endopserm cells


Correct Option: C
Explanation:

Peroxisomes are present in the photosynthetic mesophyll cells of leaves. They play an important role in photorespiration. They maintain redox balance in cells and play a role in plant immune defence. Thus the correct answer is option C.

Which of the following is covered by a single membrane?

  1. Nucleus

  2. Mitochondria

  3. Plastids

  4. Sphaerosomes


Correct Option: D
Explanation:
  • Sphaerosome is a cellular organelle enclosed by a single membrane which is only found in plant cells.
  • It helps in storage and synthesis of lipid.
  • They are formed from the endoplasmic reticulum.
  • All the other cellular organelle nucleus, mitochondria and plastids are enclosed by a double membrane.
  • So, the correct answer is 'Spherosomes'.

Enzymes associated with converting fats to carbohydrates are located in

  1. Liposomes

  2. Golgi bodies

  3. Glyoxysomes

  4. Microsomes


Correct Option: C
Explanation:
  • Enzymes associated with converting fats to carbohydrates are located in Glyoxysomes.
  • 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.
  • They contain enzymes (citrate synthase, isocitrate lyase and malate synthase etc.) which are responsible for beta-oxidation of fatty acids,
  • It helps in fatty acid oxidation, glyoxylate cycle and gluconeogenesis.
  • So, the correct answer is 'Glyoxysomes'.

Glyoxysomes are connected with metabolism of

  1. Fats

  2. Proteins

  3. Carbohydrates

  4. All the above.


Correct Option: A
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.
  •  They contain enzymes (citrate synthase, isocitrate lyase and malate synthase etc.) which are responsible for beta-oxidation of fatty acids,
  • It helps in fatty acid oxidation, glyoxylate cycle and gluconeogenesis.
  • So, the correct answer is 'Fats'.

The organelle present in germinating seeds and connected with $\beta$-oxidation or fat digestion is

  1. Glyoxysome

  2. Sphaerosome

  3. Peroxisome

  4. Mitochondrion


Correct Option: A
Explanation:
  • The organelle present in germinating seeds and connected with β-oxidation or fat digestion is glyoxysome.
  • 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.
  • They contain enzymes (citrate synthase, isocitrate lyase and malate synthase etc.) which are responsible for beta-oxidation of fatty acids,
  • It helps in fatty acid oxidation, glyoxylate cycle and gluconeogenesis.
  • So, the correct answer is 'Glyoxysome'.

Cell organelle covered by a single unit membrane is

  1. Glyoxysome

  2. Lysosome

  3. Peroxisome

  4. All of the above


Correct Option: D
Explanation:
  • Unit membrane refers to the limiting membrane of cells and cellular organelles which is composed of 3-layered structure- an inner lipid layer and two outer protein layers.
  • This unit membrane surrounds most of the cellular organelles (Golgi apparatus, glyoxysome, lysosomes, peroxisomes etc.).
  • Lysosomes, glyoxysomes and peroxisomes are single-membraned cellular organelles.
  • So, the correct answer is 'All of the above'.

What is not true of sphaerosomes?

  1. Single membrane covering

  2. Connected with fats

  3. Arise from endoplasmic reticulum

  4. Involved in photorespiration


Correct Option: D
Explanation:
  • Spherosomes or oleosomes are small cellular organelles enclosed by a single membrane that is responsible for the storage and synthesis of lipid. 
  • They are obtained from the endoplasmic reticulum, they are surrounded by a single phospholipid monolayer and are found in only plant cells.
  •  So, the correct answer is 'Involved in photorespiration'.

Which organelle is present only in plants?

  1. Glyoxysome

  2. Lysosome

  3. Peroxisome

  4. Ribosome


Correct Option: A
Explanation:
  • Glyoxysome is a type of peroxisome found in plants cells.
  • It is mainly found in the cells of fat storing tissues of germinating seeds and is also present in filamentous fungi.
  • The growing seed or the seedling utilizes the sugars synthesized from fats until it attains maturity (produce them by photosynthesis after maturity).
  • So, the correct answer is 'Glyoxysome'.