A, because plant cells do have membrane-bound nuclei. they have chloroplasts, so that isn't it. Plants don't use oxygen for photosynthesis, but carbon dioxide. The plant walls are made up of cellulose,, not lipids. It must be A.
This question has a two part answer. The first part is that an asteroid hitting the earth and the second part is massive volcanoes erupting around the world.
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.
