Tag: biology

Questions Related to biology

Which of the following is an epidermal cell?

biology tissues, organs, organ system, organism defense mechanism in plants epidermal tissue system permanent tissues and their types

  1. Guard cells

  2. Root hairs

  3. Trichome

  4. All of the above

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Correct Option: D
Explanation:
  • Epidermal cells from the outer covering or surface which is mainly involved in protection and secretion. Guard cells, root hairs, and trichome are all modification of the epidermal cells.
(i) Root hair
Structure: 
  • Unicellular hairs are the extensions of an epidermal cell of roots in the root hair zone.
Function:
It increases the surface area for absorption of water and minerals.
(ii) Epidermal appendages
Structure:
  • These are called trichomes and are epidermal cell modifications. There may be unicellular or multicellular.
Functions:
Some perform for stinging produces and some glandular secretions.
(iii) Guard cell
  • Structure:
These are bean-shaped cells present on the epidermis of the leaf.
Functions:
These help in gaseous exchange and transpiration.

The living mechanical tissue

biology plant tissues defense mechanism in plants epidermal tissue system permanent tissues and their types

  1. Parenchyma

  2. Xylem

  3. Collenchyma

  4. Sclerenchyma

Show answer
Correct Option: C
Explanation:
The living mechanical tissue in plants is collenchyma. It is found in young parts of the plant body. It provides mechanical strength to the young plant parts. It is not found in underground parts and monocots.
So, the correct option is 'Collenchyma'

Structure and functional unit of nervous system is

biology control and co-ordination in plants and animals nervous system in animals structure of neuron structure and function of neuron

  1. Nephron

  2. Cyton

  3. Neuron

  4. Axon

Show answer
Correct Option: C
Explanation:

Neurons are the structural and functional unit of the nervous system. Each neuron consists of dendrites, axon, and soma. Dendrites are the small extension of nerve cells that receive signals from sensory receptors or other neurons. The long extension of the cell body of the nerve cell is called as axon that serves to conduct the nerve impulse away from the cell body. Cyton /soma is the metabolic center of the nerve cell where the metabolic contents are manufactured. It is not involved in nerve impulse conduction. A nephron is the anatomical and functional unit of kidney and thus is the part of the excretory system. Thus, the correct answer is option C.

The nervous system is formed of 

biology structure and functions of living organisms -ii nervous system in animals structure of neuron structure and function of neuron role of receptors in the mouth types of teeth circulatory system and organs

  1. Brain

  2. Spinal cord

  3. Nerves

  4. All of the above

Show answer
Correct Option: D
Explanation:

The nervous system is a collection of cells, tissues, and organs ( brain, spinal cord, nerves ) through which an organism receives information from its surroundings and then directs the organism to respond to the stimulus.

So, the correct answer is 'All of the above'.

The organ that helps us to recall and analyse is 

biology structure and functions of living organisms -ii nervous system in animals structure of neuron structure and function of neuron role of receptors in the mouth types of teeth circulatory system and organs

  1. Muscles

  2. Brain

  3. Spinal cord

  4. Nerve

Show answer
Correct Option: B
Explanation:

The brain regulates an array of functions necessary for survival. The brain houses our mind and our memories. Most available evidence suggests that the functions of memory are carried out by the hippocampus and other related structures in the temporal lobe of the brain. The brain also helps in the analysis of various body functions.

So, the correct answer is 'Brain'.

A nucleated differentiated cell that has lost the power to divide is

biology control and co-ordination in plants and animals nervous system in animals structure of neuron structure and function of neuron

  1. Nerve cell

  2. Kidney cell

  3. Liver cell

  4. Leucocytes

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.

Which cells do not form layer and remain structurally separate?

biology control and co-ordination in plants and animals nervous system in animals structure of neuron structure and function of neuron

  1. Epithelial cells

  2. Muscle cells

  3. Nerve cells

  4. Gland cells

Show answer
Correct Option: C
Explanation:
A. Epithelial cells form the lining of surface of body. These are present in the external and internal exposed parts of the body. These cells generally rest upon a non cellular supporting layer which is called the basement membrane.
B. Muscle cells are found in the muscles and these are responsible for the movement of the body and various parts. These cells are also called myocytes or sarcocytes.
C. Nerve cells or neurons are the longest cells of the body. These form the structural and functional unit of nervous system. These cells do not form any layer and structurally separate as each neuron has two functional and morphological groups i.e. dendrites and axons.
D. Gland cells are found in various glands of body and are associated with cellular secretion of various substances.
So, the correct answer is 'Nerve cells'.

Which of the following is the part of a neuron?

biology sensations and responses nervous system in animals structure of neuron structure and function of neuron

  1. Axon

  2. Cell body

  3. Dendrite

  4. All of the above

Show answer
Correct Option: D
Explanation:

The primary components of the neuron are the soma (cell body), the axon (a long slender projection that conducts electrical impulses away from the cell body), dendrites (tree-like structures that receive messages from other neurons), and synapses (specialized junctions between neurons).

Therefore, the correct answer is option D.

The bulbous structure present at the terminal end of an axon is_______________

biology plant and animal tissues nervous system in animals structure of neuron structure and function of neuron

  1. Synaptic vesicle

  2. Synaptic knob

  3. Dendrites

  4. Schwann cell

Show answer
Correct Option: B
Explanation:

A. Synaptic vesicle store various neurotransmitters that are released at the synapse.

B. Synaptic knob-The bulbous structure present at the terminal end of an axon.

c. Dendrites-also dendrons, are branched protoplasmic extensions of a nerve cell that propagate the electrochemical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the dendrites project.

D. Schwann cell -also called neurilemma cell, any of the cells in the peripheral nervous system that produce the myelin sheath around neuronal axons.

So, the correct option is 'Synaptic Knob'.

Name the part of the neuron, where information is acquired.

biology plant and animal tissues nervous system in animals structure of neuron structure and function of neuron

  1. Axon

  2. Dendrites

  3. Synapse

  4. Schwann cells

Show answer
Correct Option: B
Explanation:
Neuron is a structural and functional unit of neural system. It is composed of three major parts- cell body, dendrites and axon.
A. Axon is a long fibre which arises from the cell body and terminates as a bulb-like structure called the synaptic knob which participate in synapse. Hence, the axons take away the information from the cell body of the neuron to which they belong.
B. Dendrites are the short fibers which arise out from the cell body. The dendrites of one neuron receive the electrical impulses from different sources and then transmit these impulses towards the cell body of the neuron to which they belong. Hence, the information is acquired here.
C. Synapse is the nerve impulse which is transmitted from one neuron to another through the junctions. It is formed by the membranes of the pre-synaptic neuron and a post-synaptic neuron.
D. Schwann cells are enclosed in myelin sheath and are lipid rich cells.
So, the correct option is 'Dendrites'.