Answer:
Explanation:
Positive phototropism is growth toward a light source, and negative phototropism is growth away from a light source. ... Sunflowers are a great example of positive phototropism, because not only do their stems curve toward the light but their flowers turn to face the sunlight as well.
Answer:
So where then did all the carbon that living organisms are built of come from? It turns out that most of the carbon we use today came from a collision with another smallish planet about 4.4 billion years ago.
Cells defend themselves from viruses, bacteria with armor of protein errors
