Answer: Spinal cord.
Explanation:
The spinal cord of the central nervous system helps to move off quickly as a part of the reflex response. Jill stepped on a tack and suddenly he realizes that he should quickly move his legs out of the tack.
The pain is not stimulated until the signals reaches from the receptor to the brain. The formation of the reflex arc ensures that the amount of potential tissue damaged is less.
It forces the body to move quickly from the place that is causing damage.Example: Moving the leg up involuntarily when stepped on pin.
This occurs because the sensory neurons connects to the motor neurons within the spinal cord.This leads to the contraction of bones and muscles.
Hence, the correct option is spinal cord.
Answer:
Due to mixing of particles present in the upper layer of limestone with sandstone during deposition.
Explanation:
The parent layer was limestone layer which is older than sandstone layer. This sandstone layer spreads on the limestone layer because of wind. The wind moves these sandstone from other region and their deposition occurs on the limestone layer. During deposition of sandstone, some particles of limestone which are present at the surface mixes with the sandstone so that's why in sandstone layer, small and weathered pieces of limestone are present.
Answer:
<u>d. Transport proteins within the membrane serve as a tunnel for molecules to enter the cell.
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Explanation:
Solutes are typically moved across the cell through either passive or active transport. The cells, surrounded by a bilipid layer or plasma membrane is amphiphlic- its polar, hydrophilic lipid heads face outwards, while their non-polar hydrophobic lipid tails face inwards towards each other.
While lipid-soluble molecules move across the layer easily, it is also difficult for charged and also large molecules to move across its surface, into the cell. Transmembrane channels, <u>embedded within the membrane</u>, help to maintain selective permeability as transport proteins, pores and gated channels. Simple diffusion happens as a method of passive transport in cells through plasma membranes.
The solutes travel through the plasma membrane in the process of diffusion from regions of high concentration to regions of low concentration; this occurs without the use of energy. <u>Molecules moving against their concentration require active transport mechanism to cross the membrane</u>.
This is True. Translocation is the movement materials from leaves to other tissues. :)
