I would say the last one. Yes, the coral reef in the south is being threaten but, it’s not the only one. Many other reefs are being threatened. Why? To find the problem to this reef you need to find the problems of other reefs and compare the data. Which ever the most problem cause you get rid of that first.
Answer:
Active uptake (which I think you mean active transport) is important when the concentration gradient is against that of a certain substance, so it doesn't cross the membrane through diffusion or passive transport. It is sometimes necessary if a substance needs to move across a membrane but can't do so due to electrical charge or that there is a substance on the other side of the membrane preventing diffusion.
Explanation:
Answer:
Due to presence at early days of the planet.
Explanation:
We only find the remains of single celled organisms in the oldest fossils because the single celled organisms are the organisms that were present in the early days of this planet. These single celled microbes were present about 3.7 billion years ago while on the other hand, the oldest rocks are only a little older i. e. 3.8 billion years so these single celled organisms are considered as oldest fossils on this planet.
Answer:
A <u><em>receptor</em></u> is a protein that recognizes and responds to a signal.
Explanation:
A receptor is a protein molecule present on the cells on which the signalling molecules can bind and generate a physiological response. Some receptor molecules can also respond to Sun and light. Each type of cell has specific receptors molecules and hence can respond to specific signals. The receptor molecules hence tend to receive signals for a cell. Molecules such as hormones bind to the receptors.
