Tag: biology

Questions Related to biology

The release of chemical messenger from synaptic vesicles is under the influence of which of these ion(s)?

biology coordination generation and conduction of nerve impulse generation of nerve impulse neurons and synapses

  1. Cl-

  2. Fe++ and s++

  3. Ca ++

  4. Mg++ and Sr++

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Correct Option: C

An action potential travelling along an axon

biology coordination generation and conduction of nerve impulse generation of nerve impulse neurons and synapses

  1. Moves rapidly in both direction

  2. Moves faster than a neurotransmitter

  3. Is slowed by myelin

  4. Travels through the blood

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Correct Option: B
Explanation:

A neurotransmitter is a chemical messenger that carries, boosts and modulates signals between neurons and other cells in the body. In most cases, a neurotransmitter is released from the axon terminal after an action potential has reached the synapse. The neurotransmitter then crosses the synaptic gap to reach the receptor site of the other cell or neuron. 

An action potential is a short-lasting event in which the electrical membrane potential of a cell rapidly rises and falls, which follows a consistent trajectory. Action potentials occur in several types of animal cells, called excitable cells, which include neurons, muscle cells, and endocrine cells, as well as in some plant cells. So, the correct answer is option B.

During depolarization, the outer surface of the membrane becomes

biology coordination generation and conduction of nerve impulse generation of nerve impulse neurons and synapses

  1. Negatively charged

  2. Positively charged

  3. Neutrally charged

  4. None of these

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Correct Option: A

Pusa Swarnim a variety of Brassica is resistant to

plant diseases keeping diseases away biology

  1. Bacterial blight

  2. White rust

  3. Curl and black rot

  4. Mosaic virus.

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Correct Option: B

Plants protect themselves from fungi by producing.

plant diseases keeping diseases away biology

  1. Protoxins

  2. Phytoalexins

  3. Prolectins

  4. All the above

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Correct Option: D
Explanation:

Protoxins-precursor of toxins.

Phytoalexins-a substance produced by plant tissues in response to contact with parasite.
Prolectins-precursor of plant lectins.
All the above can be used by plants for protection from fungi.
Correct answer-D

Which of the following is a bacterial plant disease

plant diseases keeping diseases away biology

  1. Tikka disease of Groundnut

  2. Downy mildew of Grapes

  3. Ring rot of Potato

  4. Red rot of Sugarcane.

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Correct Option: C

Symptoms of red rot disease appear over :

plant diseases keeping diseases away biology

  1. Leaf tip

  2. Whole leaf

  3. Mid rib

  4. Leaf margin

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Correct Option: C
Explanation:
The red rot of sugar cane is caused by a fungus glomurella tucumensis. Infected canes, either singly or in clumps, show a sudden orange to yellow discoloration and later the leaves gradually dry. Symptoms include Brown or reddish brown stripes appear externally at nodal region, minute red spots on the upper surface of the midrib in both the directions.

So, the correct answer is 'Mid rib'.

Match List I (Disease) with List II (Causal Organism) and select the correct answer using the code given below the lists:

List I List II
A. Blast disease of rice 1. Ustilago nuda
B. Loose smut of wheat 2. Xanthomonas malvacearum 
C. Black arm of cotton 3. Ustilago scitaminae
D. Whip smut of sugarcane 4. Pyricularia oryzae
plant diseases keeping diseases away biology

  1. A-4, B-1, C-2, D-3

  2. A-3, B-4, C-1, D-2

  3. A-4, B-2, C-1. D-3

  4. A-3, B-1, C-4, D-2

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Correct Option: A

Pusa Komal variety of Cow Pea Is resistant to disease

plant diseases keeping diseases away biology

  1. White rust

  2. Leaf curl

  3. Bacterial blight

  4. Hill bunt.

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Correct Option: C

Plants can be made disease resistant through

plant diseases keeping diseases away biology

  1. Colchicine treatment

  2. X-ray treatment

  3. Breeding with wild relatives

  4. Hormone treatment.

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Correct Option: C