Engineering Biology : Practice Questions and Answers

Cell wall is a structure made out of polysaccharide, peptidoglycan or glycoprotein that provides structural support and protection to the cell. In combination with the vacuole, which is large in plant cells, the other cell wall function includes controlling the turgidity of the cell.

The central dogma states what b option mentions. The DNA sequence in genes is copied into an mRNA. Ribosomes then read the information in this RNA and use it to create proteins. This process is known as translation i.e., the ribosome "translates" the genetic information from RNA into proteins.

Smooth ER does not contain any ribosome and is associated with cellular regions which are involved in the synthesis and transport of lipids or the detoxifications of a variety of poisons. It consists of tubules and vesicles that branch forming a network. The network of SER allows increased surface area for the action or storage of key enzymes and the products of these enzymes.

The endoplasmic reticulum serves many general functions, including the facilitation of protein folding and the transport of synthesized proteins in sacs called cisternae. Only properly folded proteins are transported from the rough ER to the Golgi complex.

The inner membrane foldings of the mitochondria is known as cristae. Cristae project into the interior of the organelle and have a variety of enzymes embedded in them. Pilli and Fimbriae have no relation with foldings. In fact they are the locomotion structures in different bacterial forms.

Centrioles play a role in the formation of the spindle apparatus which is an essential feature for both mitosis and meiosis. They are present as a pair of cylindrical rods in many eukaryotic cells. They do not have any role in providing nutrition, osmolarity etc to the cell.

The cytoskeleton is cellular "scaffolding" or "skeleton" contained within the cytoplasm and is made out of protein. Both prokaryotic and eukaryotic cells contain cytoskeleton. It has structures such as flagella, cilia and lamellipodia and plays important roles in both intracellular transport and cellular division.

Nucleoli are the structures present inside the nucleus which may be present in one, two or more than two in number. These form the subunits for ribosome which are involved in the synthesis of protein. The nucleoli are involved in the assembly and synthesis of ribosome.

The chief function of cell membranes is to regulate the passage of materials which is generally selective in nature. Keeping the cell intact, providing proper structure and shape are the accessory functions of the cell membrane which are also important for the cell growth and development.

Microtubules are filamentous intracellular structures that are responsible for various kinds of movements in all eukaryotic cells. They do not possess cell membranes whereas all other mentioned i.e. Mitochondria, chloroplast and Golgi apparatus possess a well defined and intact cell membrane.

The protein associated with the DNA of eukaryotic organisms is known as histone protein. This protein is bonded to a structure known as octamer and together they form a histone octamer. The other proteins mentioned i.e. fibrous, granular and membrane proteins are not related to the genetic aspects of a eukaryotic cell.

Flagella are structures which enable movement of an organism be it unicellular or multicelllular. They are made up of protein. An organism may be uniflagellate, biflagellate or multiflagellate depending upon the efficiency required by the organism.

Bacteria and archae are the two kinds of prokaryotes which do not have well defined nucleus and cell organelles. Viruses fall neither in the category of living nor in that of non- living. They are the intermediate or connection between living and non-living organisms.

The structure that holds the genetic material is called plasmids and not nucleolus which holds the simplified form of the genetic material in prokaryotes specifically bacteria. Other characteristics are that they do have membrane bound organelles such as mitochondria, chloroplast etc.

Bones do not contain Keratin. Their major content is calcium. Whereas hair and nails contain keratin as their major content. These are the basic chemically building units of nails and hairs which provide them strength.

Each cell consists of its own unique gene system which has the ability to replicate within the cell itself. The other mentioned options such as totipotency aren't applicable in this case because totipotency is cell specialization. Organ size and function also doesn't have any relation with different body parts possessing different cells.

All the above mentioned are statements of cell theory based upon the observation of Robert Hooke except the d) statement which is factually correct that cells aggregate to form tissues but is actually not a part of cell theory and observations based on experiment of Robert Hooke.

The first cells were discovered by Robert Hooke in 1665. He examined thin slices of cork under a self made simple microscope and found pores in it. His examination did not indicate any nucleus or cell organelles because the cells he saw were dead cells which did not possess any metabolic system.

First cells were discovered by Robert Hooke. He watched cork cells under a self made simple microscope. Leeuwenhoek discovered animalcules. Robert Koch discovered a disease called anthrax. Alexander Fleming discovered penicillin, the antibiotic for destroying the metabolic pathways of bacteria.

Mitosis can be synonymous with growth because it is an equational division of cells. Whereas when it comes to meiosis, the numbers of chromosomes become half the number of chromosomes before meiosis. Cell aggregation and cell differentiation are the concepts which are no way related to cell division.