Tag: plastids
Questions Related to plastids
Number of membranes separating intrathylakoid space from cytoplasm is
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4
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3
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2
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1
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.
Grana are
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Protein storing plastids
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Coloured plastids
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Stacks of thylakoids
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Individual thylakoids present in stroma
- 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'.
In Ulothrix, the shape of chloroplast is
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Star-shaped
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Cup-shaped
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Girdle-shaped
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Diffused type
- Ulothrix is a genus of filamentous green algae which are found in marine and fresh waters habitats.
- They have a single girdle-shaped or band-shaped chloroplast near the peripheral region of the cytoplasm (near the cell wall).
- So, the correct answer is 'Girdle-shaped'.
Structure associated with chloroplast of green algae is
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Pyrenoid
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Stigma
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Both A and B
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Endoplasmic reticulum
- 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'.
Number of grana present in a chloroplast is
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10-20
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20-30
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30-40
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40-60
- 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.
- It is made up of a thylakoid membrane which surrounds the thylakoid lumen.
- A stack of thylakoid disk is organized to form grana.
- Within a chloroplast of a plant cell, there are about 40- 60 grana and each granum are composed of 10 to 100 thylakoids.
- So, the correct answer is '40-60'.
Particles of thylakoid membranes involved in ATP synthesis are called
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Quantasomes
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$CF _0-CF _1$
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Photosystems
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Pyrenoids
- The particles of thylakoid membrane responsible for ATP synthesis is a CF$ _1$ -CF$ _O$-ATP synthase.
- It is embedded in the thylakoid membrane where the CF$ _1$-part is attached to the stroma.
- Therefore, ATP synthesis occurs on the stromal side of the thylakoid where the ATP molecules are required for carrying out the light-independent reactions of photosynthesis.
- So, the correct answer is 'CF$ _0$−CF$ _1$'.
Shape of chloroplast in higher plant is
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Discoid
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Girdle-shaped
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Reticulate
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Cup-shaped
- The chloroplast is a discoid plastid which contains chlorophyll (green pigment) within the thylakoid membranes of the organelle.
- This organelle is present in the green parts of plants where photosynthesis takes place.
- It is the main site of synthesis of glucose by the process called photosynthesis.
- The chlorophyll pigment captures the sunlight and converts it into chemical energy and thus, helps in the process of photosynthesis.
- So, the correct answer is 'Discoid'.
Number of thylakoids in a granum is
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10-100
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5-10
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100-200
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200-500
- 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.
- It is made up of a thylakoid membrane which surrounds the thylakoid lumen.
- A stack of thylakoid disk is organized to form grana.
- There are about 10 to 100 thylakoids within a granum and about 40- 60 grana in a plant cell.
- So, the correct answer is '10-100'.
Quantasomes occur in
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Stroma
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Grana/chloroplast
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Golgi body
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Mitochondria
- 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'.
All types of plastids possess essentially the same structure because they
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Perform the same function.
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Store food materials like starch, fat and protein.
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Occur in aerial parts.
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Can transform from one form to another.
Plastids are considered as sac-like organelles, generally involved in the formation or storage of food. These are chloroplast, chromoplast and leucoplast and are same in their structure to transform into one another during the requirement.