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Correct OPTION is (d) Phosphotriglycerides

The EXPLANATION is: Phospholipids present in cell membrane are diglycerides and not triglycerides. Triglycerides have THREE fatty acids and are not AMPIPATHIC in nature. It ALSO consists of sphingolipid and cholesterol.

Right answer is (c) closing

Easiest explanation: Local ANESTHETICS ACT by closing the ions channels present in the membranes of sensory cells and neurons. As a result no ACTION potential is generated and information can not be SENT to the brain about events occurring at the skin or TEETH.

Correct choice is (d) Hemolytic anemia

The BEST EXPLANATION: Hemolytic anemia is caused by the abnormal shapes of ERYTHROCYTES which have been TRACED to the mutations in ankyrin or spectrin which are plasma membrane proteins FOUND in erythrocytes.

Right CHOICE is (a) carbohydrates

For explanation: BAND 3 and GLYCOPHORINS are carbohydrate-containing membrane PROTEINS. Band 3 gets its name from the position in electrophoretic gel; it is present in the membrane as a homodimer.

Right choice is (c) continuous membrane

Explanation: Of all the CELLS in mammals, sperms are the most HIGHLY differentiated. A mature sperm is divided into THREE regions head, midpiece and tail; all having their specific functions. The sperm is covered by a continuous plasma membrane that CONTAINS a MOSAIC of specialized domains.

Right answer is (c) cholesterol

The explanation is: Cholesterol DISRUPTS the packing between fatty acyl chains and interferes with their mobility. It makes the membrane DURABLE while decreasing the PERMEABILITY of the membrane.

Correct option is (d) fluid-like

The BEST I can explain: The fluid mosaic model states that the membrane is a LIPID bilayer of fluid NATURE in which the lipid components are FREE to move about.

Right choice is (a) AVPI and AtNHX

The BEST I can explain: AvPI (Arabidopsis vacuola protein I) and AtNHX (Arabidosis transporting H^+ ION) are the antiport proteins present on the membrane of vacuole. During salt stress condition, there is an increase in NA+ ion in the CELL, which leads to acidity in cell and may be harmful to plants. These antiport transport Na^+ ion into the vacuole from cytoplasm coupled with the transport of H^+ ion from vacuole to cytoplasm. This result in reduction of Na+ concentration in cytoplasm and reduction of acidity in salt-stress condition.

The CORRECT choice is (b) desaturation

To explain I would say: When the TEMPERATURE of the surrounding is lowered, the cells respond metabolically. MEMBRANE REMODELING takes place to make the cell more cold resistant. This takes place by desaturation of fatty acyl chains to form double bonds.

Correct answer is (d) GOLD particles

For explanation I WOULD say: In the technique of single-particle tracking (SPT), individual membrane proteins are labeled with antibody conjugated gold particles and their movement is TRACED using computer-enhanced microscopy.

The correct answer is (b) False

Easy EXPLANATION: FLUIDITY and viscosity are not the same and they are inversely related. Fluidity is a measure of ease of flow and viscosity is the RESISTANCE to flow.

The correct answer is (d) 1890

For explanation: The first insights into the chemical NATURE of cell membrane came from ERNST OVERTON of the University of Zürich during the 1890s. He stated that a substance entering the cell would first have to dissolve in the boundary layer of the cell.

Correct option is (d) Photosynthesis

To elaborate: ENERGY TRANSDUCTION is the conversion of ONE form of energy to another. In photosynthesis, the energy in sunlight is absorbed by the membrane bound PHOTOSYNTHETIC PIGMENTS, converted into chemical energy and then stored as carbohydrates.

Right choice is (B) False

The EXPLANATION: Cytoplasm is the collective name of the INNER fluid of the cell which is surrounded by a plasma MEMBRANE. The soluble part of the cytoplasm is called cytosol, which is not held by any of the cell organelles.

The correct ANSWER is (b) Hypotonic solution

Best EXPLANATION: When the concentration of solute in the solution is greater than that of cell INTERIOR, it is called hypertonic solution. When the concentration of solute in the solution is greater than that of cell interior, it is called hypotonic solution. When both the solution and the cell interior has equal concentration of solute, it is called ISOTONIC solution. WATER diffuses from hypotonic solution towards cell interior with more solute concentration.

Right choice is (a) SPHINGOSINE

To explain I would say: Shingolipids are the derivative of sphingosine, an amino ALCOHOL that contains a long HYDROCARBON chain. Sphingosine is a ceramide LINKED to fatty acid by its amino group.

Correct option is (d) irritability

The best I can explain: All ORGANISMS respond to external stimulus, a property KNOWN as irritability. EVEN the SMALLEST amoeba and bacterial cell possess this feature. In response to external stimulus, a cell may activate from its whole range of metabolic pathways.

Right answer is (d) PHOSPHOLIPID

Explanation: In case of a membrane phospholipid, TWO types of movements are possible: lateral shift i. e. movement from ONE PLACE in the bilayer membrane to the other within the same leaflet; and transverse diffusion is movement of the phospholipid from one side of the membrane to the other, which is a relatively long process.

The correct choice is (B) fluidity

The EXPLANATION: At the transition temperature, the bilayer distinctly CHANGES from liquid crystalline phase to crystalline GEL. This occurs when the temperature is lowered from a standard warm temperature of 37⁰C.

Correct choice is (b) Facilitative transporter

For explanation I WOULD say: Humans consist of membrane-spanning proteins that HELP in the TRANSPORT of glucose molecules through the cell membrane. These molecules have five ISOFORMS from GLUT1 to GLUT5. It facilitates the diffusion of glucose from the bloodstream into the cell through facilitated diffusion.

Correct option is (b) Secondary ACTIVE transport

Best explanation: Primary active transport INVOLVES HYDROLYSIS of ATP or pyrophosphate or GTP to yied energy which helps in the transport of a particular molecule by utilization of that energy. Passive transport involves coupling the transport of one ion or molecule with the transport of another ion or molecule. It is of two types- Symport and Antiport. Symport refers to the pumping of two IONS in the same direction of the cell membrane while Antiport refers to pumping of ions in the opposite direction.

The correct option is (c) MEMBRANE phospholipids

Explanation: SINCE integral PROTEINS are embedded in the phospholipid bilayer of the membrane, the mobility of the integral proteins is determined LARGELY by the physical state of membrane phospholipids.

Correct choice is (a) Lowers the transition temperature

Explanation: The lipid is converted from a liquid crystalline phase to a frozen crystalline phase. The temperature at which this CHANGE OCCURS is called transition temperature. The greater degree of unsaturation in FATTY acids lower the transition temperature and it QUICKLY achieves the crystalline frozen state due to HIGH unsaturation.

The CORRECT choice is (a) True

The best explanation: Action potential can only move in the forward direction GENERATING nerve IMPULSES. This is because the area of the membrane that has just experienced action potential, remains in a REFRACTORY PERIOD and can not be stimulated again.

Right OPTION is (C) NEURONS

The explanation: Nerve cells are called neurons; they conduct, transmit and collect information in FORM of electrical impulses. The structure of neurons is unique and DIFFERENT from other cells in the body.

The correct answer is (d) sphingolipids

The EXPLANATION is: LIPID rafts are the patches of cholesterol and sphingolipids. When membrane lipids are EXTRACTED from the MEMBRANES to synthesize ARTIFICIAL membranes in vitro, cholesterol and sphingolipids tend to self-assemble.