Hairs are mostly fibrous proteins and are composed of keratin, and also the main constituent of skin, nails, wool, woof, feathers etc.
Keratin is the essential fibrous protein which has a structural and protective functions in the epithelium.
Answer:
True
Explanation:
When the resting potential of the membrane is changed, the membrane becomes either more negative inside or less negative. This small deviation from the resting potential is called graded potential. A graded potential occurs when a stimulus triggers opening or closing of the mechanically gated or ligand-gated channels present in the plasma membrane.
For example, the presynaptic neuron releases neurotransmitters in response to a nerve impulse. The neurotransmitter binds to receptors present in the plasma membrane of the postsynaptic neuron and triggers the opening of the ion channels to allow the inflow of particular ions to flow. The flow of ions changes the voltage across the membrane. This change in membrane voltage is a postsynaptic potential and is a type of graded potential.
Climate, especially temperature and rainfall patterns
Microclimates on the roof top
Strength of the supporting structure
Size, slope, height and directional orientation of the roof
Type of underlying waterproofing
Drainage elements, such as drains, scuppers and drainage conduits
Accessibility and intended use
Visibility, fit with architecture, and owner’s aesthetic preferences
Fit with other ‘green’ systems, such as solar panels
Materials and labor costs
The mechanical and chemical receptors that control digestive activity are located in the walls of the tract organs.