Answer:Enzymes are biological catalysts. Catalysts lower the activation energy for reactions. The lower the activation energy for a reaction, the faster the rate. So enzymes speed up reactions by lowering activation energy
Diatoms contain chloroplasts that have four membranes. These four membranes are evidence of secondary endosymbiosis (Option c).
<h3>What is secondary endosymbiosis?</h3>
Secondary endosymbiosis is a hypothesis used to explain why diatom chloroplasts have four membranes.
According to this hypothesis, diatoms received different genes from distinct photosynthetic and non-photosynthetic ancestors.
The acquisition of genes of different ancestors led to diatoms having chloroplasts with four membranes.
Learn more about the endosymbiosis hypothesis here:
brainly.com/question/2957447
It’s a because hdkss and this and that’s the answer
Answer:
65 million years ago
Explanation:
At the end of the Cretaceous Period. Dinosaurs became extinct at the boundary between the Cretaceous and Paleogene eras, about 66 million years ago, at a time when there was worldwide environmental change resulting from the impact of a large celestial object with the Earth and/or from vast volcanic eruptions.
