The spectral types and sub-classes represent a temperature sequence, from hotter (O stars) to cooler (M stars), and from hotter (subclass 0) to cooler (subclass 9). The temperature defines the star's "color" and surface brightness. ... Stars are also classified by luminosity class.
<u><em>Answer for question #1 : </em></u>Litter in Earth's water supply from consumer and commercial use creates a toxic environment. The water is ingested by deer, fish and a variety of other animals. The toxins may cause blood clotting, seizures or serious medical issues that can kill animals.
<u><em>Answer for question #2 : </em></u>Bottom trawling - dragging nets across the sea floor to scoop up fish - stirs up the sediment lying on the seabed, displaces or harms some marine species, causes pollutants to mix into plankton and move into the food chain and creates harmful algae blooms or oxygen-deficient dead zones.
<u><em>Answer for question #3 : </em></u>Peregrine usually nests on the cliffs of Rock Cliffs. However, the Falcons have been able to adapt to using taller buildings. Window boxes and other niches in the buildings provide a place to lay a female egg. Peregrines lay their eggs in a nest depression called a “scrape.”
<u><em>Answer for question #4 : </em></u>Decline of milkweed leads to decline in monarch butterflies, simple as that. At the garden center, we sold quite a few milkweed (asclepiads incarnate) and butterfly weed (ascidia tuberose), both of which are vital to the survival of the monarch butterfly.
