Answer:
Threats to the tundra biome
The oil, gas, and mining industries can disrupt fragile tundra habitats. Drilling wells can thaw permafrost, while heavy vehicles and pipeline construction can damage soil and prevent vegetation from returning. This activity also increases the risk of toxic spills.
What is the environment like in the tundra?
Tundra ecosystems are treeless regions found in the Arctic and on the tops of mountains, where the climate is cold and windy, and rainfall is scant. Tundra lands are covered with snow for much of the year, but summer brings bursts of wildflowers.
Explanation:
Brainliest please?
<span>Cytotoxic t-cell subpopulations are specialized to combat intracellular pathogens, whereas helper t-cell subpopulations are specialized to combat extracellular pathogens.
</span>Cytotoxic t-cell are CD8+ cells. Cytotoxic t-cell uses granzymes to <span>kill </span><span>intracellular bacteria, that lives in the cytosol such as viruses. They identify the pathogen forgein peptids that are bounded to MHC-I on the cell surface.
</span>
cd4+ T helper (Th) cells include Th1, Th2, and Th17 cells. They contribute to aliergic reactions and fighting extracellular parasites.
Answer:
A. City A because there are no pollution sources upstream.
Explanation:
Water pollution is th contamination of water. There are many means through which water is contaminated such as industrial waste, agricultural waste and domestic waste et-cetra.
City A and City B get water from sunset lake and moth lake which have factories (industrial waste) and farmland (agricultural waste) nearby them, which are responsible for the contamination of river water. due to this cities can recieve contaminated water which can affect their health.
But the quality of water in City A will be best than that of City B because according to the image, City A do not have nay upstream soooooource of pollution, as factories and farmland are located at downstream.
Hence, the correct option is A.
C they are always found in homologous pairs
