Which scenario is an example of natural selection?

•Farmers crossbreed two types of cows to produce a breed of cow that has high quality beef and can tolerate a hot climate.

•Giraffes that have longer necks survive a dry season by eating leaves from the tops of trees. Those giraffes breed more successfully that year.

•People kill rattlesnakes that rattle when approached by humans, but people do not kill rattlesnakes that remain silent. The quiet snakes survive and breed.

•Dogs that have a desirable coat color are bred with one another to produce puppies with the same coat color.

Provide one reason why mitosis occurs.

8) animals respond in various ways to stimuli detected through their senses. some of these responses are stimulated by the presence of danger. which of these animal responses is the best example of a response to an immediate threat? a) a rooster crows every morning at the first sign of light. b) as something approaches an octopus, it shoots a cloud of ink. c) from late fall until spring, bears hibernate to preserve energy. d) a dog is getting hot in the sunlight, so he moves to a shaded area.

The table presents the average day and night temperatures in five cities. it also reveals whether a city receives substantial rainfall (wet climate) or little rainfall (dry climate). which city’s rocks are likeliest to experience frost wedging, and why? a) city a because the consistently subzero temperature would prevent water from melting b) city b because it is a wet region and the temperature fluctuates around the freezing point c) city c because it receives plenty of rain fall and the weather is moderately cool d) city d because the hot and dry weather would cause rocks to absorb water