Tag: biology

Quizzes (1160) Questions (12174)

Questions Related to biology

Multiple choice biology reproduction in organisms sexual reproduction in organisms sexual reproduction & its importance modes of reproduction

Sometimes a ladder like structure in Spirogyra is formed due to

  1. Lateral conjugation

  2. Asexual reproduction

  3. Scalariform conjugation

  4. Direct conjugation
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Conjugation is an exchange of genetic material i.e, mode of sexual reproduction in lower organisms.
Scalariform conjugation: It takes place during the night and between the recently divided cells of the conjugating participating filaments. Opposite cells of two filaments develope a conjugation tube by lying side by side and parallel to each other. The conjugation tube between two filament looks like a ladder, through which gamete from one gametangia passes through to fuse with the passive gamete of another filament.

Multiple choice biology reproduction in organisms sexual reproduction in organisms sexual reproduction & its importance modes of reproduction

What would be the number of chromosomes in the aleuronic cells of a plant with $42$ chromosomes in the root tip cells?

  1. $21$
  2. $42$
  3. $63$
  4. $84$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Root tip cells are diploid (2n = 42), which means the haploid number n is 21. Aleurone cells in cereal grains are triploid (3n) endosperm tissue, so their chromosome number is 3 times 21, which equals 63.

Multiple choice biology types and parts of plants leaves root, stem, and leaves basics of roots and stem

The bulliform cells of leaves lose their turgidity during excessive _____________.

  1. Assimilation

  2. Transpiration

  3. Photosynthesis

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

In some grasses(isobilateral leaves), on epidermis, there are some larger, thin walled cells called bulliform cells are present, which in dry condition lose water through transpiration and thus the rolling up of leaves occurs, e.g., in Poa, Agropyron, Amophilla, etc.

Multiple choice biology types and parts of plants leaves root, stem, and leaves basics of roots and stem

How much water a mango tree can transprire during its growing season?

  1. $350 - 750$ liters/ day
  2. $350 - 1750$ liters/ day
  3. $750 - 3500$ liters/ day
  4. $1750 - 3500$ liters/ day
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Mango tree transpire around 100L of water per day during normal season But this transpiration reaches to 350-750 L /day during is a growing season.
So the correct option is' 350 -750liters /day'.
Multiple choice biology types and parts of plants leaves root, stem, and leaves basics of roots and stem

Meaningful girdling (ringing) experiment can not be performed within sugarcane because

(a) its phloem is situated interior to xylem
(b) its stem surface is covered with worry coating
(c) its vascular bundles are not present in a ring
(d) its stem is thin $13$. Guttation is caused by

  1. Transpiration

  2. Osmosis/ DPD

  3. Root pressure

  4. Osmotic pressure
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Guttation is the process of loss of water from the surface of leaves in the form of liquid drops. Hydathodes are the openings through which guttation takes place that are present on the margins of leaves. It occurs when root pressure is high and transpiration is low. 
So the correct answer is 'Root pressure'.
Multiple choice biology types and parts of plants leaves root, stem, and leaves basics of roots and stem

In the leaves of strawberry, water appears to be exuded through leaf margins. This is due to the combination of:
i. Adhesion
ii. Root pressure
iii. Transpiration
iv. Guttation.

  1. i, ii and iii

  2. ii, iii and iv

  3. i, ii and iv

  4. Only i, & iv
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • Guttation is the process of loss of water from the surface of leaves in the form of liquid drops. Hydathodes are the openings through which guttation takes place that are present on the margins of leaves.
  • Guttation occurs when root pressure is high and transpiration is low. Guttation is frequently seen occurring at night in herbaceous plants growing under conditions of high soil moisture and high atmospheric humidity.
  • Water rises up in the process due to the property of Adhesion.
So, the correct option is 'i, ii and iv'.
Multiple choice biology types and parts of plants leaves root, stem, and leaves basics of roots and stem

Transpiration.

  1. There are stomata on the leaves of the plants.Through these opening the excess of water is thrown out in the form of water vapors. This process is called transpiration

  2. There are two guard cells around the opening of stomata.They have an external membrane. They control the opening and closing of the stomata.

  3. Also come amount of water is lost due to evaporation from the leaves.

  4. As a result, water level in the epidermal layer of the leaf decrease

  5. To compensate this loss,more water is brought to the leaves through the xylem.

  6. Transpiration thus helps in absorption of water and minerals and their distribution to all parts of the plant

  7. Root pressure pushes the water up during the night time.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Transpiration is the biological process where plants lose water in the form of vapor through the stomata on their leaves.

Multiple choice biology types and parts of plants leaves root, stem, and leaves basics of roots and stem

The droplets of water arranged at the edges of leaves of roses in the morning are

  1. Water drops condensed from the atmosphere during night at low temperatures

  2. Water transpired from the stomata and lenticels

  3. Water produced on the leaves from the reaction of hydrogen and atmospheric oxygen

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Water droplets formed on the edge, tip, or the underside of leaves is not dew because dew comes from water condensing from the air and tends to settle evenly on the leaf’s upper surface.
Transpiration is the evaporative loss of water by plant. When the soil is too wet, water penetrates the plant through its roots and this creates pressure that forces the water to exit the plant in the form of droplets. This process doesn’t occur during the day, because the leaf’s stomata are open at that time. It occurs when the stomata close down, i.e. at night and water pressure begins to build up. Therefore, the droplets can be noticed when the sun comes up in the morning, before the drops evaporate.
So, the answer is B.