Answer:
Eukaryotic cells probably evolved about 2 billion years ago. Their evolution is explained by endosymbiotic theory. Mitochondria and chloroplasts evolved from prokaryotic organisms. Eukaryotic cells would go on to evolve into the diversity of eukaryotes we know today.
Hope this helps.
Explanation:
How will what affect polar bears?
Answer:
The sun (abiotic) affects the grass, trees, flowers, etc. by giving off its energy to the plants so they can grow.
Another example is water (abiotic) affects mostly every biotic factor such as humans, plants, or animals because all living things need water to survive.
Answer:
Angle of light source
Explanation:
Independent variable is the variable that the experimenter changes or manipulates in an experiment in order to bring about a measurable response, which is the dependent variable.
In this question, a student wants to investigate the effects of phototropism in bean plants. She places a light source directly above one plant, at a forty-five degree angle to another, and at a ninety-degree angle from the third. This shows that the variable being manipulated (independent variable) is the ANGLE OF THE LIGHT SOURCE.