Answer:
Two groups of proteins, called cyclins and cyclin-dependent kinases (Cdks), are responsible for the progress of the cell through the various checkpoints. Cyclins regulate the cell cycle only when they are tightly bound to Cdks.
Explanation:
Groundwater is the water found beneath the earth's surface in spaces in soil, in cracks and rocks. These spaces are called aquifers. Groundwater serves many purposes where most of it is used in irrigation purposes. In the year 2005, 68 percent, most of the groundwater withdrawals, were used for irrigation, 19 percent was for public supply and the remaining 13 percent was used for other applications in industries.
Answer:
d) A chemical change results in a new substance being formed; whereas, a physical change will result in a different state of matter.
Explanation:
Answer:
thermal energy to heat our homes; mechanical energy to transport people and things; and electrical energy to power just about every other technology we use.
Explanation:
Answer:
B. Contains the male gametophytes
Explanation
The male cones release their pollen, which is carried around the air by blowing wind, and hopefully to another female pine cone on a different pine tree. Sorry this isn't under 20!
