E) All of the answers are correct.
Ion channels are proteins located in the membrane that allow ions to pass through the channel pore. Ion channels can be classified (by what opens and closes the channels) into few groups:
• Voltage-gated channels-open and close in response to membrane potential
Examples: Voltage-gated proton channels, Voltage-gated sodium channels, Voltage-gated potassium channels
• Ligand-gated (neurotransmitter) or ionotropic receptors (ligand binds to extracellular domain of the receptor
Examples: "nicotinic" Acetylcholine receptor, ionotropic glutamate-gated receptors
• Lipid-gated- lipid molecules bind to the transmembrane domain of the channel
Example: Inward-rectifier potassium channels
• Light-gated channels-like rhodopsin channel that is directly opened by photons
• Mechanosensitive (e.g. stretch, pressure) ion channels.
Living indicators are species that are sensitive to changes in the environment. For example air pollution can be monitored by looking at lichen, which are sensitive to sulphur dioxide in the air. The number of lichen at a particular location indicates how clear the air is. Similarly, mayfly larvae are good indicators for water pollution because they're sensitive to the concentration of dissolved oxygen in water.
Non-living indicators are things like satellites which can measure the temperature of the sea surface, weather stations that measure atmospheric temperature, rain gauges to measure rainfall, and dissolved oxygen meters to measure concentration of dissolved oxygen in water.
Answer:
Genotype ratio = 1 X^hX : 1 XX : 1 X^hY : 1 XY
Phenotype ratio = 2 normal daughters : 1 affected son : 1 normal son
Explanation:
Given that the father of the woman has hemophilia, the father must have transferred the allele for hemophilia (let us assume "h") to her. This makes the woman carrier for the disease (genotype = X^hX). The genotype of the normal man would be "XY".
A cross between carrier woman and normal man would obtain 2 normal daughters, 1 affected son and 1 normal son.
Genotype ratio = 1 X^hX : 1 XX : 1 X^hY : 1 XY
Phenotype ratio = 2 normal daughters : 1 affected son : 1 normal son
