Cell wall: strong; supporting layer around the cell membrane in plant cells
Answer: D. Epinephrine
Explanation:
During perceived danger the fight-or-flight response includes faster heart beat, quickened breath, tense muscles and thought speed up. This co-ordinated set if physiological changes is triggered by two hormones of the adrenal gland, epinephrine and norepinephrine.
The major activities of these hormones is to increase the amount of chemical energy available for immediate use, increase the heart rate and stroke volume and dilate the bronchioles in the lungs, action the raise the rate of oxygen delivery to the cell.
Answer is epinephrine
Contour: Gives the bird its stream line shape.
<span>Down feathers: Keeps the bird warm.</span>
Answer:
Explanation:
An important property of DNA is that it can replicate, or make copies of itself. Each strand of DNA in the double helix can serve as a pattern for duplicating the sequence of bases. This is critical when cells divide because each new cell needs to have an exact copy of the DNA present in the old cell.