Prokaryotic and Eukaryotic Cells
GATE Microbiology Prokaryotic & Eukaryotic Cells
Questions
The length of DNA molecule greatly exceeds the dimensions of the nucleus in eukaryotic cell. How is this DNA accommodated within the little sphere of nucleus?
- Deletion of genes
- Through elimination of repetitive DNA
- Supercoiling of nucleosomes
- DNAase digestion
Endoplasmic reticulum maximises surface area and provides mechanical support by acting as the cytoskeleton. It produces_________.
- >10% of total membranes in cell
- >25% of total membranes in cell
- 50% of total membranes in cell
- hardly 1% of total membranes in cell
Which of following observations highly supports the view that mitochondria possess electron transport system enzymes?
- Disruption of mitochondria harvest membrane fragments that are capable of synthesising ATP.
- Mitochondria possess a characteristic to concentrate within cells that produce locomotory structures.
- Mitochondria posses a folded inner membrane.
- A contractile protein able to utilise ATP is get from mitochondria.
When a splitting cell is treated with the hydrogen peroxide, its spindle fibers precipitate because of disulphide bridges formation. Such reaction denotes that spindle fiber and microtubules are_____________.
- non-polar organic structures
- glycosyl structures
- proteinaceous structures
- none of the above
Which of the following clues would tell you whether a cell is prokaryotic or eukaryotic?
- The presence or absence of a rigid cell wall.
- Whether or not the cell is partitioned by internal membranes.
- The presence or absence of ribosomes.
- Whether or not the cell carries out cellular metabolism.
Which of following statements is correct about carbohydrate portion of cell membrane?
- It provides to polycationic charge on extracellular surface.
- It has a symmetrical distribution.
- It is present primarily in kind of free saccharides groups.
- It produces glycocalyx composed of glycolipids and glycoproteins.
According to Singer & Nicholson’s model, which of following is found in plasma membrane?
- Phospholipids & chitin
- Phospholipids, intrinsic & extrinsic proteins, glycoproteins & glycolipids
- Cellulose & hemicelluloses
- Protein & carbohydrate
Protochlorophyll varies from chlorophyll in lacking
- 4 H atoms in 1 of its pyrrole ring
- 4 H atoms in 2 of its pyrrole ring
- 2 H atoms in 1 of its pyrrole ring
- 2 H atoms in 2 of its pyrrole ring
Fast and irreversible elongation of cell occurs usually in plants but not in the animals. Such difference is because of_________.
- presence of huge vacuoles and cell walls
- absence of endoplasmic reticulum and presence of huge vacuoles
- presence of chloroplast and mitochondria
- absence of centrioles and golgi bodies
Mitotic cell cycle is categorised usually into 4 phases- G1, S, G2 and M. Considering mitotic cycle time of 18 hours, distribution of time period (in hours) for every phase will be___________.
- G1 - 1, S - 3, G2 - 5, M - 9
- G1 - 9, S - 1, G2 - 3, M - 5
- G1 - 9, S - 5, G2 - 3, M - 1
- G1 - 3, S - 5, G2 - 9, M - 1
Large eukaryotic ribosome’s sub-unit consists of__________.
- 23S rRNA + 5S rRNA + 4.5 rRNA + 33 proteins
- 23 rRNA + 5.8 S rRNA + 33 proteins
- 28S rRNA + 18S rRNA + 41 proteins
- 28S rRNA + 5.8S rRNA + 5S rRNA + 49 proteins
2 ribosomal sub-units remain together with each other because of____________. -
- high concentration of Mg++ ions
- low concentration of Mn++ ions
- high concentration of Ca++ ions
- low concentration of Mg++ ions
Nucleosomes is the ellipsoidal bead shape structure with the length of 110A & diameter of 65-70A. Its core composed of an histone octamer & its surface is surrounded by super-helical DNA strand of about_________.
- 265 BP
- 110 BP
- 140 BP
- 210 BP
A precise evidence, which states that in particular cases, RNA produces genetic hereditary material comes from the fact that__________.
- RNA initially enters genes followed by DNA
- when virus particles are extracted individually from infected host, only RNA is present to form infection
- RNA is capable of dissociating itself & can enter the genetic materials
- RNA codes for DNA, which then produces protein molecules
Mitochondria causes maximum cell’s supply of ATP and their quantity within a cell is simply associated with metabolic activity. Cellular respiration is performed out of the mitochondria. Mitochondrial matrix composed of variety of enzymes that play a major part in metabolic pathway. These involve carbohydrate, lipid, amino acids, urea & heme biosynthesis.
Mitochondrial morphology is controlled by balancing active absorption of water & active secretion by mitochondrion. Hence, mitochondria swell in__________.
- uncoupling agent
- uncoupling catalysing oxidative phosphorylation
- ATP
- hypertonic solution
Which of following are essential properties of prokaryotes (methanogenic bacteria)?
- These cannot develop automatically.
- Those dwelling in mud supernatant may need organic development factors for development.
- These cannot transform hydrogen to methane.
- These cannot utilize CO2 as growth substrate in which CO2 is reduced to methane.
Choose the right answer using the options provided below:
- 1, 2 and 3
- 1, 3 and 4
- 1, 2 and 4
- 2, 3 and 4
Mitochondria causes maximum cell’s supply of ATP and their quantity within a cell is simply associated with metabolic activity. Cellular respiration is performed out of the mitochondria. Mitochondrial matrix composed of variety of enzymes that play a major part in metabolic pathway. These involve carbohydrate, lipid, amino acids, urea and heme biosynthesis.
Which of following mechanism is utilised by mitochondria to transform energy in cellular metabolism?
- Mitochondria trap chemical energy and reserve it in form of high energy lipid bonds.
- Transfer of electrons from NADH to O2 occurs in inter membrane space.
- Mitochondria control an electrochemical protein gradient which represents stored energy.
- The respiratory chain pumps protons into mitochondrial matrix.
Cell division is, where a parent cell is divided into 2 or more daughter cells. Typically, cell division occurs as part of larger cell cycle. In eukaryotes, it is of 2 types: vegetative (daughter cell is similar to parent cell) & reductive (chromosome number in daughter cell is decreased by half for producing haploid gametes) cell division. Prokaryotes also possess vegetative cell division termed as binary fission.
The mitosis promoting factor (MPF) that propels the animal cell into division stage has 2 important sun units: 1 is catalytic & other is regulatory. Which of following is regulatory sub unit of MPF?
- Ubiquitin
- Cyclin
- Cdk (Cyclin dependent kinase)
- Proline
Cell division is where a parent cell is divided into 2 or more daughter cells. Typically cell division occurs as part of larger cell cycle. In eukaryotes, it is of 2 types: vegetative (daughter cell is similar to parent cell) & reductive (chromosome number in daughter cell is decreased by half for producing haploid gametes) cell division. Prokaryotes also possess vegetative cell division termed as binary fission.
Colchine arrests either mitotically dividing cell at metaphase by__________.
- dislodging chromosomes from fibrous elements of spindle and consequently the chromosome remain confined to equatorial plane
- preventing movement of spindle fibers as the result of which chromosomes fail to go to opposite poles
- preventing polymerisation of tubulin into microtubules of spindle
- destroying contractile property of spindle protein which ultimately coagulates
Match the Column I with Column II & choose the right answer using the following options provided below the column:
| Column I | Column II |
| A. Conduction of secretion to various organelles within a cell | 1. Nuclear pores |
| B. Intracellular osmosis | 2. Endoplasmic reticulum |
| C. Granular material exchange between nucleus & cytoplasm | 3. Cell membrane |
- A - 2, B - 3, C - 1
- A - 1, B - 3, C - 2
- A - 3, B - 1, C - 2
- A - 2, B - 1, C - 3