Answer:
B. The membrane lets certain substances move across it freely, while others must move through a “gate”.
Explanation:
Selective permeability is a property of cellular membranes that only allows certain molecules to enter or exit the cell. This is important for the cell to maintain its internal order irrespective of the changes to the environment. For example, water, ions, glucose and carbon dioxide may need to be imported or exported from the cell depending on its metabolic activity. Similarly, signaling molecules may need to enter the cell and proteins may need to be released into the extracellular matrix. The presence of a selectively permeable membrane allows the cell to exercise control over the quantum, timing and rate of movement of these molecules.
This is true - psychology measures observable behaviours and used scientific methods
Answer:
Which of the following is true of the composition of all materials?
All materials are made up of smaller parts that cannot be seen without magnification
Explanation:
Material composition entails smaller parts that made up of such materials which are embedded in it. it could be chemical, addictive, which are not seen
Answer:
Aerobic means with oxygen.
A cold front does count as weather, if you're looking for more info on cold fronts and warm fronts visit the site below.
http://www.weatherquestions.com/What_are_fronts.htm
