Answer:
C. At least five mass-extinction events have occurred during the last 500 million years.
Explanation:
- The history of mass extinct is related to the five mass extinctions that are caused over by the 350 million years n which many species have disappeared in there short geologic time.
- A massive extinction is caused in the Permian Triassic extinction event i.e about 250 mn years ago which on an estimate has killed 90% of the species.
- The Cretaceous–Paleogene extinction event that occurred over 66 million years ago is known to have wiped out the dinosaurs and many other species.
<span>The trick here is to understand the definition of each of the cellular transport or function mechanisms listed. These are some interesting (and strange) analogies!
Facilitated Diffusion
This is when a mechanism assists in diffusing (spreading) some material into an environment. The dog on the wagon going through a spring loaded door would shoot it out into the environment. This is an odd analogy but Point 3 would be the one.
Active Transport
Is when energy is expended to transport molecules somewhere against a concentration gradient or some other barrier. Examples include transporting molecules across a cell wall. The best analogy is the dog being dragged into a bathtub (Point 1).
Phagocytosis
This is when a larger cell consumes a molecule often like eating. This matches to point 2 - the child eating the doughnut.
Passive Diffusion
Is when a concentration of molecules naturally diffuse into an environment. This suits point 5 - the crowded room full of people.
Pinocytosis
Is the budding of cell membranes to consume liquid in the surrounding environment. I guess a woman drinking tea is the closest analogy listed (Point 4).</span>
Answer:
In North America, around June 21, Earth tilts on its axis toward the sun, which is Summer Solstice and when the Northern Hemisphere has the most daylight of any time of year. Winter solstice the Northern Hemisphere tilts the farthest away from the sun and when we have the least amount of daylight of any time of the year.
Explanation:
As Earth revolves around the Sun, it rotates on its axis. Sometimes Earth tilts toward the Sun which is when Summer occurs. In the Winter Earth tilts away from the Sun.
A. Duplication is one of the different types of chromosomal mutations.
Tuberculosis vaccines are vaccinations intended for the prevention of tuberculosis. Immunotherapy as a defence against TB was first proposed in 1890 by Robert Koch. Today, the only effective tuberculosis vaccine in common use is bacilli Calmette-Guérin, first used on humans in 1921.
