Answer:
Early cyanobacteria in stromatolites are thought to be responsible for increasing the amount of oxygen in the primeval Earth's atmosphere through their continuing photosynthesis. They were the first known organisms to photosynthesize and produce free oxygen.
Hope this helps!!!
Answer:
Epinephrine binds to receptors on some smooth muscles (ex: around arterioles) → Ca++ released from ER → intracellular Ca++ up → stimulates contraction. c. Epinephrine binds to receptors on some smooth muscles (ex: around bronchioles) → phosphorylates protein needed for response to Ca++, preventing response.
<span>Bones are linked together at skeletal joints by </span>cartilage I believe.
The organelle that temporarily breaks apart so that the DNA can divide up is the nucleus. Nucleus store most of the cell's DNA it is responsible for carrying genetic information. It is also responsible for generating genetic expression to ensure the proper activities of the entire cells.
The correct answer is:
Plants close their stomata during times of intense heat or drought in order to prevent water loss and maintain homeostasis.
Explanation:
Guard cells tend to open stomata within the day when there are lots of day and close stomata at night when the sun is not present and photosynthesis is not happening. They will also close stomata if the air is dry or hot, which minimizes water waste indoors evaporation.
