Biology · Science General

Cell Biology and Structure

3,062 Questions

Cell biology focuses on the structure and function of cellular organelles. Key topics include cellular respiration, DNA inheritance, and energy production. These fundamental biology concepts are crucial for medical entrance and state service examinations.

Cell organelles functionsCellular respiration sitesDNA and ribosomesAnimal cell structurePlant cell components

Cell Biology and Structure Questions

Multiple choice botany plant tissues permanent tissues and their types simple permanent tissues tissues: plant tissues

Choose the correct answer from the alternatives given.
Sclerenchymatous cells in their cell walls have large percentage of:

  1. silica

  2. lignin

  3. pectin

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

Answer B: Lignin

Sclerenchyma is composed of dead cells with extremely thick cell walls that make up to 90% of the whole cell volume. Their walls consist of cellulose and/or lignin.

               

Multiple choice botany plant tissues permanent tissues and their types simple permanent tissues tissues: plant tissues

We get a crunchy and granular feeling, when we chew pear fruit because of the

  1. Presence of stone cells (sclerenchyma)

  2. Presence of stone cells (parenchyma)

  3. Presence of stone cells (collenchyma)

  4. Presence of stone cells (aerenchyma)
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

  • Parenchyma cells are alive, thin-walled cells. They are present in soft parts of the plant. But pear fruit has hard parts inside, which give it a gritty texture. Therefore, option B is incorrect. 
  • Collenchyma cells are thin-walled with some areas of secondary thickening. They provide extra structural support and flexibility to plant. Therefore, option C is incorrect.
  • Aerenchyma cells are present in an aquatic plant. Such cells have large air cavities, which enable the plant to float in water. 
  • Sclereid is a reduced form of sclerenchyma, which has thickened lignified walls. In pear fruit, sclereid cells are present in bundles, which give a gritty texture to the fruit. Such cells are also called "stone cells" because of their hardness.

So, the correct answer is option A.

Multiple choice botany plant tissues permanent tissues and their types simple permanent tissues tissues: plant tissues

Which of these cells in a plant is apt to be nonliving?

  1. Epidermal

  2. Sclerenchyma

  3. Collenchyma

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

the sclerenchyma tissue is present in stems, around vascular bundles, in the veins of leaves and in the hard covering of seeds and nuts. It is the tissue which makes the plant hard and stiff due to the presence of lignin in the cell wall. The cells of this tissue are dead. So, the correct answer is "sclerenchyma".

Multiple choice botany plant tissues permanent tissues and their types simple permanent tissues tissues: plant tissues

Stereome comprises

  1. Sclerenchyma

  2. Collenchyma

  3. Non-living cells of vascular tissues

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

Stereome is a mechanical tissue which is formed due to polysaccharide deposition. This is seen in sclerenchyma, collenchyma and all non-living cells of vascular tissues. The deposition of polysaccharides thickens the cell walls in all the three tissue types. Collenchyma is formed due to the deposition of cellulose and is a living tissue. Sclerenchyma is formed due to the deposition of lignin and is a dead permanent tissue.

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

Multiple choice bio-chemistry cell-the basic unit of life introduction to cell discovery and cell theory cell discovery cell discovery and cell theory cell as structural and functional unit
Omnis cellula e cellulae i.e., new cells arise from pre-existing cells, this statement was given by

  1. Schleiden and Schwann

  2. Rudolf Virchow

  3. Robert Brown

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

Rudolf Virchow modified the cell theory and gave the concept of 'omnis cellula e cellulae' - means new cells develop by division of the pre-existing cells. This is called theory of cell lineage or common ancestry.

So, the correct answer is 'Rudolf Virchow'.

Multiple choice bio-chemistry cell-the basic unit of life introduction to cell discovery and cell theory cell discovery cell discovery and cell theory cell as structural and functional unit

Cells are the .......... structural units of living organism.

  1. Largest

  2. Smallest

  3. Oldest

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

  • Cells are called the smallest structural and functional unit of life because all the living organisms are made up of cells and also all the functions taking place inside the body of organisms are performed by cells. 

So, the correct answer is option B.

Multiple choice bio-chemistry cell-the basic unit of life introduction to cell discovery and cell theory cell discovery cell discovery and cell theory cell as structural and functional unit

Most of the cells are ........... in size and are not visible to the unaided eye.

  1. Microscopic

  2. Macroscopic

  3. Regular

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

  • The cells are microscopic in size and are not visible to the unaided eye with the size from 0.5 micrometers to 50 micrometers. 
  • They need to be enlarged or magnified by a microscope. 
  • The electron microscope discovered by Knoll and Ruska was able to magnify the cellular structure.
So, the correct answer is option A.

Multiple choice bio-chemistry cell-the basic unit of life introduction to cell discovery and cell theory cell discovery cell discovery and cell theory cell as structural and functional unit

A cell is the .......... and functional unit of an organism.

  1. Longest structural

  2. Smallest structural

  3. Biggest structural

  4. Strongest structural
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • Cells are called the smallest structural and functional unit of life because all the living organisms are made up of cells and also all the functions taking place inside the body of organisms are performed by cells. 
Multiple choice bio-chemistry cell-the basic unit of life introduction to cell discovery and cell theory cell discovery cell discovery and cell theory cell as structural and functional unit

Define cell.

  1. A thick solution mainly composed of water, salts and proteins

  2. Basic structural, functional and biological unit that can replicate independently

  3. Biopolymers or large biomolecules essential for all known forms of life

  4. All of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

  • The cells are the basic structural, functional and biological unit of all known living organisms. 
  • Cells are the smallest unit of life that can replicate independently and are often called the building blocks of life. 
  • The human body is composed of trillions of cells. 
  • They provide structure for the body, take in nutrients from food, convert those nutrients into energy and carry out specialized functions. 
  • Cells also contain the body's hereditary material and can make copies of them.
So, the correct answer is option B.

Multiple choice bio-chemistry cell-the basic unit of life introduction to cell discovery and cell theory cell discovery cell discovery and cell theory cell as structural and functional unit

All living things including plants and animals are made up of 

  1. Cell

  2. Cell wall

  3. Nucleus

  4. Plastids
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • The first characteristic of a living thing is that they are made up of cells. A cell is a basic building block of all organisms. 
  • It is the smallest unit of organization in a biosphere. A cell performs the life process to maintains the survival of an organism.
Multiple choice bio-chemistry cell-the basic unit of life introduction to cell discovery and cell theory cell discovery cell discovery and cell theory cell as structural and functional unit

Bricks in a building and cells in the living organisms are 

  1. Basic structural unit

  2. Basic model

  3. Basic unit

  4. Basic structure
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Cells are called the structural and functional unit of life because all the living organisms are made up of cells and also all the functions taking place inside the body of organisms are performed by cells. Cells provide specific conditions, for the occurrence of the metabolic reactions. These have specialized enzymes, which catalyze the biochemical reaction and regulates the functions of the body.
Multiple choice bio-chemistry cell-the basic unit of life introduction to cell discovery and cell theory cell discovery cell discovery and cell theory cell as structural and functional unit

Cells are said to contain

  1. Individuals

  2. Life span information

  3. Both A and B

  4. DNA
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • The cell is considered to be the basic unit of life in many pathological processes. 
  • In addition, the phenomenon of energy flow occurs in cells in processes that are part of the function known as metabolism. 
  • Cells contain hereditary information (DNA), which is passed from cell to cell during cell division and from one generation to next. Thus, the correct answer is option D
Multiple choice bio-chemistry cell-the basic unit of life introduction to cell discovery and cell theory cell discovery cell discovery and cell theory cell as structural and functional unit

What is the structural and functional unit of living organisms?

  1. Tissue

  2. Cell

  3. Organ

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

Cells are called the structural and functional unit of life because all the living organisms are made up of cells and also all the functions taking place inside the body of organisms are performed by cells. Cells provide specific conditions, for the occurrence of the metabolic reactions. These have specialized enzymes, which catalyze the biochemical reaction and regulates the functions of the body.

Multiple choice bio-chemistry cell-the basic unit of life introduction to cell discovery and cell theory cell discovery cell discovery and cell theory cell as structural and functional unit

The ______ is the basic structural and functional unit of life.

  1. Tissue

  2. Organ

  3. Cell

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

The cell is the basic structural and functional unit of life. Whether it is a complex organism like humans, animals or plants or simple organisms like the bacteria, they are all made of cells. So, the cell forms the most basic level of organization of organisms.