Tag: biology

Questions Related to biology

A nucleated differentiated cell that has lost the power to dedifferentiate is ____________.

biology organization of life the cell structure cytoplasm number and shape of cells

  1. Nerve cells.

  2. Kidney cells.

  3. Liver cells.

  4. All of the above.

Show answer
Correct Option: A
Explanation:
A nucleated differentiated cell that has lost the power to division are nerve cells. These are the cells of nervous system and carry electrical messages and signals throughout the body. They have lost their power to division because the existing ones can grow new connections by loosing the old ones and also these cells needs oxygen and nutrients and if it divides rapidly and get packed, it will become difficult to supply and hence will starve.
So, the correct answer is option A.

RBCs are

biology organization of life the cell structure cytoplasm number and shape of cells

  1. Differentiated cells.

  2. Undifferentiated cells.

  3. Dedifferentiated cells.

  4. Dead cells.

Show answer
Correct Option: A
Explanation:

Mammalian erythrocytes also called as red blood cells are formed in bone marrow from multipotential hemocytoblast and further converted to erythroblast (normoblast). The nucleus and mitochondria of erythroblast disappear and it is converted to mature erythrocyte with haemoglobin. So RBC's are differentiated cells which lack a nucleus.

Which one of the following is anucleate?

biology organization of life the cell structure cytoplasm number and shape of cells

  1. Sieve tube

  2. Companion cell

  3. Medullary ray

  4. All of the above

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Correct Option: A

Formation of meristems cork cambium from fully differentiated parenchyma cells is an example of :

biology organization of life the cell structure cytoplasm number and shape of cells

  1. Differentiation

  2. Redifferentiation

  3. Dedifferentiation

  4. Regenration

Show answer
Correct Option: C
Explanation:
Cambium is the layer which forms Cork and acts as a secondary meristem from a layer of collenchyma or parenchyma immediately beneath the epidermis. The cells which produce from cork cambium will differentiate and will get mature to perform a specialized function. The living cells which lost the capacity to divide can regain the capacity of the division under certain conditions is called as 'Dedifferentiation.'
So the correct option is 'Dedifferentiation.'

Any specialized plant cell that is dispersed among cells of a different kind is called a

biology organization of life the cell structure cytoplasm number and shape of cells

  1. Marcophyll

  2. Xenophyte

  3. Normoblast

  4. ldioblast

Show answer
Correct Option: D
Explanation:
An idioblast is an isolated plant cell that differs from neighboring tissues. They have various functions such as storage of reserves, excretory materials, pigments, and minerals. They could contain oil, latex, gum, resin, tannin or pigments etc. So, the correct answer is "Idioblast."

Dedifferentiated cells are formed in the region of

biology organization of life the cell structure cytoplasm number and shape of cells

  1. Injury.

  2. Regeneration.

  3. Secondary growth.

  4. All of the above.

Show answer
Correct Option: D
Explanation:

An undividable differentiated cell sometimes gains the power to divide. This process is called dedifferentiation. Wound healing after injury and secondary growth in plants are some of the best examples of dedifferentiation. Dedifferentiation is one of the mechanisms of natural regeneration. So answer D is correct.

Which of the following is false?

adaptations - european woodland and african grassland adapting to a habit plant adaptations adaptations to different ecosystems biology

  1. Quantity of biomass in a trophic level at a particular period is called as standing crop.

  2. The energy content in a trophic level is determined is determined by considering a few individuals of a species in that trophic level.

  3. The succession that occurs in newly cooled lava is called primary succession.

  4. Rate of succession is faster in secondary succession.

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Correct Option: B

Tropical rain forests are subsidized by

adaptations - european woodland and african grassland adapting to a habit plant adaptations adaptations to different ecosystems biology

  1. Wind and Rain

  2. Tides, waves, currents

  3. Nuclear energy

  4. Solar energy

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Correct Option: A

The adaptation mechanism of chameleon is

adaptations - european woodland and african grassland adapting to a habit plant adaptations adaptations to different ecosystems biology

  1. To hibernate in the winter

  2. Changing colours to suit with its surroundings

  3. To develop scaly skin on its body to maintain moisture

  4. To migrate to long distances in the winter

Show answer
Correct Option: B
Explanation:

Chameleon can change its colour which helps the animal to camouflage itself in the presence of potential predators. Their slow movement and blending into the surrounding environment make it hard for predators to spot them. Their colour changes also help them in mating as they shift colours while communicating with other chameleons. Their colour change also depicts their reactions such as they display darker colours when empty or when under stressed environmental conditions.  Thus, the correct answer is option B.

Tigers and leopards have stripes on their bodies. This adaptation helps them 

adaptations - european woodland and african grassland adapting to a habit plant adaptations adaptations to different ecosystems biology

  1. To keep their bodies cool

  2. To keep their bodies hot

  3. To mix with the surroundings

  4. To look beautiful

Show answer
Correct Option: C
Explanation:

The different types of stripes in tigers and leopards are ideal in proving camouflage to these animals according to their need. The black stripes help the animal to be hidden in the shades of the tree. The stripes on their body look like shadows as they stalk through long grasses in the moonlight. Besides being an adaptation to mix with their surroundings these stripes also act as finger prints for them as no two tigers have same type of stripes.

Thus, the correct answer is option C.