Hello!
There are two possible answers to this. The one I'm assuming you're looking for is hydrogen bonds.
Hydrogen bonds are the bonds which hold together the double helix shape of DNA. These bonds result from a positive and negative charge drawing two molecules closer to each other. These bonds are generally seen as weak, however, since there are so many of these bonds (as there are so many nitrogenous bases in one strand of DNA), the double helix strand is fairly strong.
Hope this helps!
The direct source of energy to move the sailboat is probably wind, since wind is what pushes the sail of the sailboat, which is what propels the sailboat forward.
Hope this helps!
Answer:
a To provide cows and other live stock with vaccines so diseased do not spread among farmers and cattle herders.
Explanation:
because that one makes the most sense and it is true
Answer:
The SR-71 Blackbird.
Explanation:
The Lockheed SR-71 "Blackbird" was an American strategic reconnaissance aircraft that traveled at over mach 3, or 3 times the speed of sound. The Concorde was a French passenger jet with a top speed of just over mach 2. The Bell X-1 was the first supersonic test plane and had to be dropped from a larger plane to reach altitude.
Answer:
<em>The correct option is B) as the light colored moths were seen and eaten, the allele for dark colour became more prevalent in the population.</em>
Explanation:
The process of natural selection tends to favour those organisms which are better adapted to live in an environment. Evolution changes the allele frequencies of a population over time depending on the traits favoured by natural selection.
Before the industrial revolution, the colour of the trees was lighter and hence, the light coloured moths were better adapted to such environments as they could hide from predation. After the industrial revolution, the colour of the woods of trees became darker. The light coloured moths were no more able to hide from their predators and hence their population declined.
