17=3
18=4
I'm not that sure about 17, but I think it's right
Answer :There was enough oxygen in the atmosphere to support a major burst of life on Earth
Explanation:
The Great Oxygen Event marks the time, approximately 2.5 billion years ago, when there was enough oxygen in the atmosphere to support a major burst of life on Earth
For the first half of the Earht's history, there was no oxygen in the atmosphere. It was inhabited only by single-celled organisms.Of those simple life forms, the cyanobacteria may have. evolved a way to take energy from sunlight, and used it to make sugars out of water and carbon dioxide. They used the same chemical process we know as photosynthesis. This released vast quantities of oxygen into the atmosphere and triggered the evolution of complex life.
Answer:
"low cost of water to users and lack of government subsidies for improving the efficiency of water use"
Explanation:
- low cost of water to users and lack of government subsidies for improving the efficiency of water use
The leading cause of water pollution? agriculture.
In the western United States, as compared to the eastern United States, the major water problem is chronic drought and insufficient runoff
Answer:
Phenotype
Genotype
Explanation:
Phenotype is the physical appearance because it's the outward expression of the person, which is determined by one's Genotype.
Answer:
unicellular - both prokaryotes and eukaryotes
contain mitochondrion - eukaryotes only
are generally less than 2 pm - Prokaryotes only
multicellular - eukaryotes only
lack membrane-bound organelles - prokaryotes only
Explanation:
Prokaryotes are generally unicellular, that is, they are made up of single cells only. However, there are unicellular and multicellular eukaryotes with some eukaryotes like humans and advanced plants having as many as millions of cells.
Prokaryotes generally lack nucleus and other membrane-bound organelles such as chloroplast and mitochondrion. Eukaryotes on the other hand have nucleus and membrane-bound organelles such as mitochondrion and chloroplast.
When it comes to size, prokaryotes are generally small and microscopic while eukaryotes consist of both microscopic and macroscopic cells or organisms. However, prokaryotes are generally smaller than microscopic eukaryotes.
