The Fundamental Unit of Life

 Option (2) is correct.

The most important features distinguishing the cells of plants from those of animals is the presence of cell wall in plants. This wall protects the cellular contents. A plant's cell wall is composed of several compounds among which cellulose is the most important. Cellulose is made up of molecules of the sugar glucose. Cellulose molecules are united into fibrils (layers of fibres), which form the structural framework of the wall. Other components of cell walls are lignin (provide rigidity) and waxes (reduce water loss from cells).

<span style="font-size:11.0pt;font-family:Arial;mso-fareast-font-family:"Times" new="" roman";mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa="">Animal cell is prokaryotic in nature - False statement. Animal cell has a well defined nucleus. So it is an eukaryote and not a prokaryote (without nucleus) . Therefore, (B) is the correct answer. 

RER looks rough under a microscope because it has particles called ribosomes attached to its surface.

Reason: DNA (Deoxyribonucleic acid) is present in the nucleus of the cell. Along with nucleus, DNA is also present in mitochondria and chloroplast (in plants) but not in golgi apparatus, ribosomes and vacuole.. Mitochondria and chloroplast are referred to as strange organelles in the sense that they have their own DNA and ribosomes involved in protein synthesis. Therefore, both organelles are able to make some of their own protein. Therefore (C) is correct answer. 

Genes - Functional segments of DNA are called genes which regulates the process of development of a cell. Functional segments mean that the information encoded within the DNA structure of a gene directs the manufacture of proteins that carry out life supporting activities. 

If the medium has exactly the same water concentration as the cell; there will be no net movement of water across the cell membrane. Such a solution is known as isotonic solution. The cell will remain of the same size.

Reason: Hypertonic - high solute (salt) concentration and low water level outside the cell. If the medium has lower concentration of water than the cell, meaning that it is very concentrated solution; the cell will lose water by exosmosis. Such a solution is known as hypertonic solution. (Osmosis - is the passage of water from a region of high water concentration through a semi-permeable membrane to a region of low water concentration. Thus, osmosis is a special case of diffusion through a semi permeable membrane). <o:p>More water will leave the cell through cell membrane than enters it. Therefore, the cell shrinks. When a living plant cell loses water through osmosis there is shrinkage of the contents of the cell away from cell wall since it is rigid. This phenomenon is known as Plasmolysis (Plasma = protoplasm, lysis - Breakdown) 

Reason: Presence of chromosomes, presence of mitochondria (power house of the cell) and presence of lysosomes are similar in both plants and animals. The difference between the two lies in the nature of vacuoles. <o:p>Vacuoles are small sized animal cells while large size in plant cells. The central vacuole of some plant cells may occupy 50 - 90% of the cell volume. In plant cells, vacuoles are full of cell sap (which is made up mostly of water containing various dissolved sugar, salts and other chemicals) and provides turgidity and rigidity to the cell. Many substances of unimportant in life of plant cell are stored in vacuoles. 

Endoplasmic Reticulum - is a large network of membrane bound tubes and sheets. It looks like long tubules or round or oblong bags (Vesicles). They are of two types viz. Rough ER and Smooth ER. It always forms a network system in a cell. 

Reason: Multicellular - made up of many cells<o:p>
Fish, Cockroach and pea plant - are examples of animals, insects and plants which are multicellular.<o:p>Paramecium - is an example of protozoans which are a type of Protist (unicellular eukaryotic organism). Therefore, Paramecium is a unicellular organism as it is made up only one cell.   

Nucleus has a double layered covering called nuclear membrane. It is composed of DNA and protein. DNA molecules (Deoxyribonucleic acid) contain the information necessary for constructing and organising cells. Eukaryotes is the correct answer. Organisms with cells having a nuclear membrane are called eukaryotes, e.g. plants, animals.

Cell membrane of a eukaryotic cell bears respiratory enzymes. Respiratory enzymes is an enzyme, such as oxidases, that transfer electrons from its substrate to molecular oxygen. During cellular respiration, cell membrane bears respiratory enzyme in prokaryotic cells but in eukaryotes cell, membrane lacks respiratory enzyme. In case of eukaryotic cell, respiratory enzymes are present in mitochondrial membrane. 

Amoeba has no definite shape or size because it uses amoeboid movement, as a form of locomotion. They can create extensions of their body wall called pseudopodia (false feet) that helps them to locomote or capture prey. 

Osmosis - is the movement of water from a region of high water concentration or low solute concentration to low water concentration or high solute concentration through a semi-permeable membrane. Thus, osmosis is a special case of diffusion through a semi permeable membrane. (Membrane which allows the entry and exit of only water and not solute). So, it is the correct answer. 

Reason: Pigments are stored in chromoplasts and chloroplasts (stores green pigments).

Nucleus - plays a central role by determining the way the cell will develop and what form it will exhibit at maturity, by directing the chemical activities of cell. This is because nucleus enclose chromosomes which are composed of DNA and protein. Fundamental segments of DNA are called genes which regulate the process of development of a cell. 

Cytoplasm - is the fluid content inside the plasma membrane but outside the nuclear membrane. It also contains many specialized cell organelles. It is water like substance of cell. If we stain cheek cells or onion peel cells with methylene blue nucleus will take up the stain & appear as a dense structure whereas cytoplasm does not take up the stain. 

Nucleoid: In bacteria (prokaryotes), the nuclear region of the cell is poorly defined due to the absence of nuclear membrane. Such an undefined nuclear region containing only nucleic acids is called a Nucleoid. 

Photosynthesis - is a process by which green plants make their own food. Photosynthesis occurs in leaves and green stems within specialized cell organelle called chloroplasts as they contain green pigment (chlorophyll) which is required for the process of making food (photosynthesis). 

spontaneous (occurring naturally) movement of gases across a permeable membrane from a region of high concentration to the region of low concentration is known as diffusion.<o:p>e.g. Carbon dioxide (CO₂) (Which is a cellular waste required to be excreted out by the cell) accumulates in high concentrations inside the cell. In the cell's external environment, the concentration of carbon dioxide (CO₂) is low as compared to that inside the cell. As soon as there is difference in concentration of CO₂ inside and outside a cell, CO₂ moves out of the cell from a region of high concentration to a region of low concentration outside the cell by the process of diffusion. Similarly oxygen (O₂) enters the cell by the process of diffusion when the level or concentration of oxygen inside the cell decreases.

Plastid - are present only in plant cells. Plastid containing pigment chlorophyll are known as chloroplasts which are important for photosynthesis in plants. Photosynthesis does not occur in animals. 

Chromosomes - In a cell which is not dividing, DNA is present as a part of chromatin material. Chromatin material is visible as entangled mass of thread like structures, But whenever the cell is about to divide, the chromatin material gets organized into chromosomes. Chromosomes are composed of DNA and protein. 

Reason: Cells vary in shape and size. The smallest cell, a type of bacterium known as Mycoplasma, measures 0.0001 mm in diameter. Amongst the largest cells are nerve cells. These cells can exceed 3 m in length. Along with the differences in size, cells are present in different shapes. In humans outermost skin cells are flat while nerve cells are elongated. In multicellular organisms shape and size of the cell is mainly dependent on its job or functions.<o:p>For example - flat skin cells pack tightly into a layer that protects the underlying tissue from invasion by bacteria. The numerous extensions from a nerve cell enable it to connect to several other nerve cells in order to send and receive messages rapidly. 

Golgi apparatus consists of a system of membrane bound vesicles arranged approximately parallel to each other in bundles or stacks, called cisterns. These membranes often have connections with the membrane of endoplasmic reticulum and therefore constitute another portion of a complex cellular membrane system. 

<span style="font-size:11.0pt;font-family:Arial;mso-fareast-font-family:"Times" new="" roman";mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa="">ATP - Adenosine tri phosphate, molecule found in all living organisms that is the main immediate source of usable energy for the activities of the cell. ATP (Adenosine tri phosphate) is provided in the form of energy by the cell organelle- mitochondria. 

Deoxy - Removal of oxygen <o:p>DNA is the genetic material found in all living organisms. Functional unit of DNA is called genes which regulates the process of development of a cell. All characters of individual are dependent on the types of genes. DNA is made up of deoxyribose sugar which is a fine carbon sugar (one atom of oxygen is removed from the ribose sugar). It also consists of nucleic acid. Nucleic acid are made up of bases, sugar and phosphate group. Bases are of 4 types in DNA consisting of Adenine (A), Thymine (T), Guanine (G) and Cytosine (C).(B), (C) and (D) are wrong terms.

Reason: If the medium surrounding the cell has a higher water concentration than of the cell, meaning that the outside solution is very dilute, the cell will gain water by osmosis. Such a solution is known as hypotonic solution. The net result is that water enters the cell. The cell will swell up.<o:p>
Vacuole - are small sized in animal cells while large size in plant cells. The central vacuole of some plant cells may occupy 50 - 90% of the cell volume. In plant cells, vacuoles are full of cell sap (which is made up mostly of water containing various dissolved sugar, salts and other chemicals). <o:p>
Plastids- are present only in plant cells. Plastid containing pigment chlorophyll are known as chloroplasts which are important for photosynthesis in plants. Photosynthesis does not occur in animals.<o:p>
Cell wall - Plant cells are rigid because of presence of cell wall made up of cellulose which is lacking in animal cell. This is the reason why plant cells do not burst and become turgid when placed in hypotonic solution whereas animal cells burst off when placed in hypotonic solution as cell wall is absent in them.<o:p>Nucleus encloses the chromosome in both plants & animals.

Hypertonic - high solute (salt) concentration and low water level. If the medium has lower concentration of water than the cell, meaning that it is very concentrated solution the cell will lose water by exosmosis. Such a solution is known as hypertonic solution.<o:p>More water will leave the cell through cell membrane than enters it. Therefore, the cell will shrink. When a living plant cell loses water through osmosis there is shrinkage of the contents of the cell away from cell wall. This phenomenon is known as Plasmolysis (Plasma = protoplasm, lysis - Breakdown) 

Reason: Bacterium belong to the kingdom Monera which are composed of unicellular organisms.
Fungus: They are multicellular organisms belonging to kingdom animalia.
Plants & Animals: They are multicellular eukaryotes. 

<span style="font-size:11.0pt;font-family:Arial;mso-fareast-font-family:"Times" new="" roman";mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa="">Mitochondria - is a membrane bound organelle and prokaryotes do not have membrane bound organelles. 

Lysosomes - do not carry genetic information. They act as a waste disposal system in the cell. Lysosomes help to keep the cell clean by digesting any foreign material as well as worn out cell organelles. This is the reason why they are also known as “suicidal bags” Therefore the correct answer for this question is a Lysosome.

<span style="font-size:11.0pt;font-family:Arial;mso-fareast-font-family:"Times" new="" roman";mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa="">Chloroplast - Animals are heterotrophs which are dependent on others for food. Chloroplast are present only in plants as they are autotrophs and synthesize their food with the help of chlorophyll through the process of photosynthesis. 

<span style="font-size:11.0pt;font-family:Arial;mso-fareast-font-family:"Times" new="" roman";mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa="">Mitochondria - are known as “powerhouses of the cell” as they provide energy in the form of ATP (Adenosine Tri phosphate) for various chemical activities in the cell. Mitochondria have two membrane covering. The outer membrane is porous (permeable-permitting the movement of fluid or gases through it) while inner membrane is deeply folded. These folds create a large surface area for ATP-generating chemical reactions.

<span style="font-size:11.0pt;font-family:Arial;mso-fareast-font-family:"Times" new="" roman";mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa="">Cytoplasm - Present both in plants and animals. The cytoplasm is a fluid containing organelles with specialized functions and organelles are present both in plants & animals. 

Reason: Nucleus contains chromosomes, which are visible as a rod shaped structures only when the cell is about to divide chromosomes composed of DNA and protein. DNA (Deoxyribose nucleic acid) helps in carrying information from parents to next generation. DNA is negatively charged and proteins associated with it are positively charged. The role of protein is to pack DNA. Vitamins or lipids cannot be used to pack DNA.Therefore (B) is correct answer 

Cell was first discovered by Robert Hooke in 1665. He observed the cells in a cork slice with the help of a primitive microscope.

Presence of cytoplasm -Present both in prokaryotes and eukaryotes. The cytoplasm is a fluid containing organelles with specialized functions and organelles.

<span style="font-size:11.0pt;font-family:Arial;mso-fareast-font-family:"Times" new="" roman";mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa="">Cell Wall - Plant cells are rigid because of presence of cell wall made up of cellulose which is lacking in animal cell. 

Reason: Plasma membrane is a thin molecular layer that surrounds all living cells. The plasma membrane separates the cell from its surroundings and protects it from changes in its environment. The plasma membrane is primarily composed of 2 types of molecules.<o:p>
(1)        Lipids - Which are fats or oil molecules. Lipids help in transporting fat soluble substances across membrane.<o:p>
(2)        Proteins - Help in transporting substances across the membrane.<o:p>
            In most cells, plasma membrane is about 40% of Lipids and 60% of protein.<o:p>Vitamins like fat soluble (Vitamin A, D, E, K) or water soluble (Vitamin B, C) are not able to perform functions like lipids and proteins.Therefore they are not present in cell membrane. However, Carbohydrates along with protein e.g. glycoprotein are present in cell wall.