Biology · Science General

Cell Biology and Structure

3,221 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 caskets of life the cell structure multicellular organisms number and shape of cells

The mature cells in the mammalian body, i.e., RBC loses their capacity for

  1. Aerobic respiration

  2. DNA replication

  3. RNA synthesis

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

Nucleus is double membrane covered protoplasmic body that contains hereditary information. A nucleus is absent in some mature cells like mammalian RBCs and sieve tube cells in plants. They are called as enucleate cells. In mammals, erythrocytes also lose all other cellular organelles such as their mitochondria, Golgi apparatus and endoplasmic reticulum. As a result of not containing mitochondria, these cells use none of the oxygen they transport; instead they produce energy by glycolysis of glucose and lactic acid fermentation of the resulting pyruvic acid.

Thus, the correct answer is option D.

Multiple choice botany caskets of life the cell structure multicellular organisms number and shape of cells

Which of the folwing statement can be related to 'It is said that every multicellular organism has come from a single cell'?

  1. Every organism starts its life from a zygote, a single cell.

  2. Cells divide to produce cells of their own kind and thus, all cells of the body come from the pre-existing cells.

  3. Both A and B.

  4. None of the above.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

All the multicellular organisms start their life with a single cell (zygote). Later, it is divided and differentiated into different cell types in multicellular organisms. Cells are capable of dividing to form their own kind of cells. Thus, all cells of the body come from the pre-existing cells. Thus, the correct answer is option C.

Multiple choice botany caskets of life the cell structure multicellular organisms number and shape of cells

Which one of the following is the smallest in size?

  1. Bacteria

  2. Mitochondrion

  3. Mammalian cell

  4. Virus
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The average diameter of bacteria is 0.2 to 2 micrometer. 
Mitochondrion size is 0.5 to 10 micrometer. 
The average diameter of a mammalian cell is 20 micrometer. 
Virus diameter ranges from 20 nanometers to 250-400 nanometer. 1000 nanometer = 1 micrometer. Hence, the virus particle is the smallest of all.

Multiple choice botany caskets of life the cell structure multicellular organisms number and shape of cells

Cells of multicellular organism are usually________________

  1. Triangular

  2. Rectangular

  3. Polyhedral

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

Cells of unicellular organisms are usually spherical due to surface tension. 
Cells of the multicellular organism are usually polyhedral. Because polyhedral cells have more neighbors which means more intercellular exchange can occur. Also, the polyhedral group of cells resists stretching to a more extent. 

Multiple choice botany caskets of life the cell structure multicellular organisms number and shape of cells

The life of .......... organisms start with a zygote.

  1. Acellular

  2. Unicellular

  3. Multicellular

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

In unicellular, reproduction occurs asexually and two new identical daughter cells that are produced. All multicellular start their life from a single cell i.e., zygote which is a product of the fusion (fertilization) of usually two haploid gametes, a female and a male gamete. The zygote (diploid) divide to give rise huge variety of different types of cell, specialized for different functions which in turn forms multicellular organism.

Multiple choice botany caskets of life the cell structure multicellular organisms number and shape of cells

Match the following:
A                                                                                B
A. Barr body                             1   Gives a grey colour to the
                                                          cell body
B. Purkinje cells                       2. Condudion muscles of
                                                        heart.

C. Nissl bodies                           3. Present in neurilemma
D. Schwann cell                          4. Certain neurons having
                                                           flask shaped cylons.

E. Purkinje fibres                          5. Found in cylons of female.
The correct pairing is.

  1. 5, 4, 1, 3, 2

  2. 3, 2, 5, 1, 4

  3. 5, 2, 1, 3, 4

  4. 4, 3, 2, 5, 1
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Barr bodies are found in the cells of females (5). Purkinje cells are flask-shaped neurons in the cerebellum (4). Nissl bodies give a grey color to the cell body (1). Schwann cells are present in the neurilemma (3). Purkinje fibers are conduction muscles of the heart (2).

Multiple choice botany caskets of life the cell structure multicellular organisms number and shape of cells

Few genes are found in all types cells

of differentiated multicellular organisms of high

class. It is called

  1. Key genes

  2. Core genes

  3. House keeping genes

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Core genes refer to the genes present in all the cells of an organism.
Housekeeping genes are those genes which are always expressed in a cell and code for various proteins that are required for the normal functioning and sustenance of cell. These genes are expected to maintain constant expression levels in all cells and at all conditions. Lethal gene is the gene that generally formed by the mutation and causes the death of the organisms.
Thus, the correct answer is option B.
Multiple choice botany caskets of life the cell structure multicellular organisms number and shape of cells

A multicellular organism possesses

  1. Differentiated cells.

  2. Undifferentiated cells.

  3. Dedifferentiated cells.

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

A multicellular organism attains its multicellularity from a single cell. Single totipotent cell undergo number of mitotic and meiotic divisions to give rise to a multicellular structure where cells undergo differentiation to a particular function. Some of the cells are undifferentiated such as stem cells which can give rise to any type of cells of the body. Also multicellular organisms undergoes dedifferentiation process where a differentiated cell revert back to totipotent cell and can again differentiate to a particular type of cell witha particular function. So Multicellular organisms posses all these type of cells so Answer D is correct.

Multiple choice botany caskets of life the cell structure multicellular organisms number and shape of cells

Functionally important dead cells are

  1. Cork cells.

  2. Tracheary elements.

  3. Endothelial cells.

  4. Both A and B.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Cork cells (phellem) are dead at maturity and provide protection. Tracheary elements (xylem vessels and tracheids) are also dead at maturity and function in water transport. Both are functionally important dead cells.

Multiple choice botany caskets of life the cell structure multicellular organisms number and shape of cells

Any organism performed all the activities by single cell is called as

  1. Multicellular

  2. Unicellular

  3. Acellular

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

An organism which performs and exhibits all functions of life via a single cell, it is an unicellular organism. Such as prokaryotes like bacteria, eukaryotes like yeast are unicellular organisms. They lack conglomerate of cells (tissue) or organ systems to perform specific functions. All the cellular functions for it to be living are performed by the individual cell.  So, the correct answer is 'Unicellular'.

Multiple choice botany caskets of life the cell structure multicellular organisms number and shape of cells

Which of the following statements concludes that ruminants are multicellular animals?

  1. They have specialized organs for digestion.

  2. They can reproduce.

  3. They have lungs for breathing.

  4. Both A and C.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Reproduction is the characteristic for living organisms i.e., both unicellular and multi cellular organisms can reproduce irrespective of their cellular level. But, only multi cellular organisms have specialized organs for digestion and respiration/breathing that is GIT (Gastro Intestinal Tract) and Respiratory tract respectively, unlike unicellular organisms who respire and engulf food by general body surface. Thus, digestive tract and respiratory tract are defining feature of multicellular organism (ruminant). 
So, the correct answer is 'Both A and C'.