Tag: biology

Quizzes (1160) Questions (12174)

Questions Related to biology

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

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

  1. Cl-

  2. Fe++ and s++

  3. Ca ++

  4. Mg++ and Sr++
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When an action potential reaches the axon terminal, voltage-gated calcium channels open. The influx of Ca++ ions triggers the fusion of synaptic vesicles with the presynaptic membrane, releasing neurotransmitters into the synaptic cleft.

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

An action potential travelling along an axon

  1. Moves rapidly in both direction

  2. Moves faster than a neurotransmitter

  3. Is slowed by myelin

  4. Travels through the blood
Reveal answer Fill a bubble to check yourself
B Correct answer
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.

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

During depolarization, the outer surface of the membrane becomes

  1. Negatively charged

  2. Positively charged

  3. Neutrally charged

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

During depolarization, sodium ions rush into the cell, making the interior more positive. Consequently, relative to the interior, the outer surface of the membrane becomes negatively charged compared to its resting state.

Multiple choice plant diseases keeping diseases away biology

Pusa Swarnim a variety of Brassica is resistant to

  1. Bacterial blight

  2. White rust

  3. Curl and black rot

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

Pusa Swarnim is a biofortified and disease-resistant variety of Brassica (mustard) specifically developed for resistance against White rust.

Multiple choice plant diseases keeping diseases away biology

Plants protect themselves from fungi by producing.

  1. Protoxins

  2. Phytoalexins

  3. Prolectins

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

Multiple choice plant diseases keeping diseases away biology

Which of the following is a bacterial plant disease

  1. Tikka disease of Groundnut

  2. Downy mildew of Grapes

  3. Ring rot of Potato

  4. Red rot of Sugarcane.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ring rot of potato is caused by the bacterium Clavibacter michiganensis subsp. sepedonicus. The other options listed are fungal diseases.

Multiple choice plant diseases keeping diseases away biology

Symptoms of red rot disease appear over :

  1. Leaf tip

  2. Whole leaf

  3. Mid rib

  4. Leaf margin
Reveal answer Fill a bubble to check yourself
C Correct answer
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'.
Multiple choice plant diseases keeping diseases away biology

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

  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
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Blast disease of rice is caused by Pyricularia oryzae (A-4). Loose smut of wheat is caused by Ustilago nuda (B-1). Black arm of cotton is caused by Xanthomonas malvacearum (C-2). Whip smut of sugarcane is caused by Ustilago scitaminae (D-3).

Multiple choice plant diseases keeping diseases away biology

Pusa Komal variety of Cow Pea Is resistant to disease

  1. White rust

  2. Leaf curl

  3. Bacterial blight

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

Pusa Komal is a well-known variety of cowpea bred for resistance to bacterial blight.

Multiple choice plant diseases keeping diseases away biology

Plants can be made disease resistant through

  1. Colchicine treatment

  2. X-ray treatment

  3. Breeding with wild relatives

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

Breeding with wild relatives is a traditional and effective method to introduce disease-resistance genes into cultivated crop varieties.