External skeleton is the correct answer. Hope this helps out !
Just like other cells, the part of the bacterium that is able to interact with its outside environment is its cell membrane. Generally, the main function of the cell membrane is for barrier and protection. This decides which molecules will be allowed to permeate or not. Hope this helps.
The correct answer is C. A windstorm blew down trees in the Boundary Waters Canoe Area in Minnesota on July 4, 1999.
Explanation:
A weather event refers to a specific phenomenon in weather that in most cases is not common but particular and specific, which is different to weather patterns, this includes specific hurricanes, abnormal rain patterns, etc. Considering this, the one that is an example of a weather event is "A windstorm blew down trees in the Boundary Waters Canoe Area in Minnesota on July 4, 1999" because this is a specific phenomenon rather than a pattern in weather as int the case of hurricane seasons or permanent weather conditions.
Option D is correct.
A synapse is the opening between neurons that neurotransmitters pass through.
Answer: Paleozoic
Explanation: The Paleozoic Era, which ran from about 542 million years ago to 251 million years ago, was a time of great change on Earth. The era began with the breakup of one supercontinent and the formation of another plants became widespread. And the first vertebrate animals colonized land.
