Hello there.
<span>Regulation of the cell cycle is dependent upon cyclins and cyclin-dependent kinases. The key(s) that allows a cell to progress beyond the restriction point is (are)
</span><span>c. cyclin A and Cdk2.
</span>
Answer:
I'm pretty sure the first one is c. The second one is b.
Explanation:
1-The longest a total solar eclipse can last is 7.5 minutes.
2-The width of the path of totality is usually about 160 km across and can sweep across an area of Earth's surface about 10,000 miles long.
3-Almost identical eclipses occur after 18 years and 11 days.
4-This period of 223 synodic months is called a saros.
5-Each year there are between 2 and 5 solar eclipses.
6-The total solar eclipse, when the Moon completely obscures the Sun and leaves only the faint solar corona, is known as a Totality.
7-Total solar eclipses are rare, happening only once every 18 months.
8-Total solar eclipses produce harmful rays that can cause blindness.
9-If any planets are in the sky at the time of a total solar eclipse, they can be seen as points of light.
10-During a total solar eclipse, conditions in the path of totality can change quickly. Air temperatures drop and the immediate area becomes dark.
11- A solar eclipse can only occur when the Moon is close enough to the ecliptic plane during a new moon
The correct option is A.
Living organisms depend on their environment to survive, when there are changes in the environment which are not favorable to the living organisms, it will eventually leads to the wiping out of the living organisms. As time goes on and the environment recover, the living organisms that will be found in the new environment are those who will be able to survive in it.
