Tag: cell structure and micro-organisms

Questions Related to cell structure and micro-organisms

Conversion of $NO _3^-$ to $NO _2^-$ occurs in-

biology cell structure plant and animal cell cell structure and micro-organisms organisation of the organism

  1. Cytosol of plant cells

  2. Chloroplast

  3. Mithochondria

  4. Peroxisome

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Correct Option: A

A plant cell placed in $0.7\,M$ sugar solution was found with no change in cell volume. If the same plant cell is placed in $0.7\,M$ of $NaCl$ solution , then there will be

biology cell structure plant and animal cell cell structure and micro-organisms organisation of the organism

  1. No change in cell volume

  2. Increase in cell volume

  3. Decrease in cell volume

  4. initial increase and eventually decrease in cell volume

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Correct Option: A

Planet cells that are photosynthetically  active are found in the ______ layer of leaf and are ____ cells.

biology cell structure plant and animal cell cell structure and micro-organisms organisation of the organism

  1. Epidermis ,Parenchymatous

  2. Mesophyll,Parenchymatous

  3. Mesophyll, Sclerenchymatous

  4. Aerenchyma,Collenchymatous

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Correct Option: A

Which is incorrect for chloroplast

biology cell structure plant and animal cell cell structure and micro-organisms organisation of the organism

  1. Presence in algae and plants

  2. Release $O _2$

  3. Occurs only in cells with aerobic respiration

  4. None

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Correct Option: C

In plant cell, the vacuole

biology cell structure plant and animal cell cell structure and micro-organisms organisation of the organism

  1. Contains air and lacks membrane

  2. Contains water and excretory substances but lacks membrane

  3. Contains storage protein and lipids and is membrane bound

  4. Is membrane bound, contains water and excretory substances.

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Correct Option: D

Stratum germinations is an example of which kind of
epithelium

biology cell structure plant and animal cell cell structure and micro-organisms organisation of the organism

  1. Cuboidal

  2. Ciliated

  3. Columnar

  4. Squamous

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Correct Option: C
Explanation:

Epidermis has several distinct layers of epithelial cells. The innermost layer called stratum germinations has columnar cells resting upon a common basement membrane.

The glyoxysomes in a plant cell ___________________.

biology cell structure plant and animal cell cell structure and micro-organisms organisation of the organism

  1. Detoxify the hydrogen peroxide produced in the cell

  2. Store the waste products released in the carbohydrate metabolism

  3. Break down the fatty acids during the respiration of lipid

  4. Convert glycol ate into glycine

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Correct Option: A

Chloroplast contains maximum quantity of _________________.

biology cell structure plant and animal cell cell structure and micro-organisms organisation of the organism

  1. Pyruvic carboxylase

  2. Hexokinase

  3. RUDP caboxylase

  4. None of the above

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Correct Option: C
Explanation:

Pyruvate carboxylase is a mitochodrial enzyme that catalyzes carboxylation of pyruvate into oxaloacetate. Hexokinase is an enzyme of glycolysis and is present in the cytoplasm. RUBP carboxylase catalyzes carboxylation of RuBP during photosynthetic carbon fixation. Chloroplasts is the site of photosynthesis and contain maximum quantity of RUBP carboxylase. The correct answer is C.

In a chloroplast, what is the ration of chl a : chl b and carotenes : xanthophylls respectively?

biology cell structure plant and animal cell cell structure and micro-organisms organisation of the organism

  1. 3 : 1 and 2 : 1

  2. 2 : 1 and 3 : 1

  3. 3 : 2 and 1 : 1

  4. 1 : 1 and 3 : 2

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Correct Option: A
Explanation:

  • A chloroplast is the site of photosynthesis, it contains all the pigments required for the process of photosynthesis. Pigments are of two types: Chlorophylls and Carotenoids.
  • Chlorophylls are the green photosynthetic pigments, they are of mainly five types - chlorophyll a, b, c, d, and e. The amount of chlorophyll b is one-fourth of the total chlorophyll content while chlorophyll a is the universal or primary photosynthetic pigment and present in abundance.
  • Carotenes are hydrocarbons, they may be yellow, brown or reddish pigments.
  • Xanthophylls are oxygen-containing carotenes, yellowish brown in color.
So, the correct option is '3: 1 and 2: 1'.

Dye injected into a plant cell might be able to enter an adjacent cell through _______.

biology cell structure plant and animal cell cell structure and micro-organisms organisation of the organism

  1. microtubule

  2. microfilament

  3. plasmodesmata

  4. tight junction

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Correct Option: C
Explanation:

Plasmodesmata are cytoplasmic bridges between adjacent plant cells which develop in minute pores of their walls. They form protoplasmic continuum called symplast. It provides channels for controlled passage of small sized particles between adjacent cells as well as transfer of some specific signals.