Cell: The Unit of Life

An experimenter was analysing homogenized cell lysate (containing mitochondrial + chloroplastic + cytoplasmic contents) of a plant tissue that is heavily infected with a bacterial pathogen. Ribosomal RNA (rRNA) purified…

Differential centrifugation is a technique used to separate cell components on the basis of size and density. The larger and denser components experience the greatest centrifugal force and sediment to form a pellet at…

A small viral peptide can insert its 6 amino acids (represented as a barrel) into the lipid bilayer as depicted in the figure given below. The table depicts the different properties of amino acids. The best suitable…

The haemocytometer is a thickened glass slide with small chamber of grids cut into the glass and is used to count cells. Each chamber has a fixed volume and is etched into nine large squares (see figure, $\mathbf{P}$ to…

The presence or absence of certain sub-cellular components in the cells of three organisms ($\mathrm{P}, \mathrm{Q}$ and R) is given below. $P, Q$ and $R$ could most likely be:

A piece of liver tissue is homogenized in a laboratory and the homogenate is subjected to sequential centrifugation at increasing speeds (expressed in $\times \mathrm{g}$). Centrifugation is used to separate…

Two spherical unicellular organisms, X and Y, have the same cytoplasmic composition, metabolic pathways, and live in identical nutrient-rich aerobic conditions. The diameters of X and Y are, respectively, $10$ and $20$…

Accumulation of $\mathrm{H}_2 \mathrm{O}_2$ is harmful for the survival of eukaryotic cells. The level of $\mathrm{H}_2 \mathrm{O}_2$ in the cell is kept under control by ______ .

A researcher incubated algal cells with a fluorescent-labelled cytidine analogue that can enter the cells and get incorporated into nucleic acids. The cells were lysed and different membrane-bound organelles were…

The permeability of molecules across a lipid bilayer depends on their size and solubility in a nonpolar solvent relative to their solubility in water. For the species $\mathrm{O}_2, \mathrm{H}_2 \mathrm{O}$,…

Consider two spherical cells $\mathbf{P}$ and $\mathbf{Q}$ with radii of 1 micrometer and 0.01 millimetre respectively. Choose the statement that is correct regarding these cells.

During evolution, the mitochondrial genome lost many genes, and some of these got incorporated into the nuclear genome. Proteins synthesized in the cytoplasm are transported to various destinations, including some that…