Answer:
The membrane is selectively permeable because substances do not cross it indiscriminately.
Explanation:
Answer:
7th Science Honors Ch. 4 Vocab
A B
population size: the number of individual organisms present in a population at any given time
population density: the number of individuals in a population per unit of area
population distribution: how organisms are arranged within an area; sometimes called population dispersion.
Explanation:
Cyanobacteria, also known as blue-green algae, are found in vast quantities in fresh and salt water. Cyanobacteria are able to conduct photosynthesis. By utilising energy from the sun, they produce carbohydrates from water and carbon dioxide. As a byproduct, they produce oxygen. So cyanobacteria provided oxygen to the atmosphere that allowed other lifeforms to develop.
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