A food chain shows a single connected path of energy flow through an ecosystem. It shows the different levels of eating in an ecosystem. Both a good web and a good chain include a number of organisms including both producers and consumers. A food chain is very simple while a food web is complex and consists of a number of food chains. In a food chain each organism has only one consumer or producer.
Answer:
Gradually, as generations of elephants continued to selectively use and develop their trunks.
Explanation:
Jean-Baptiste Lamarck was famous French Naturalist. He was a soldier, a biologist and an academic. He gave an early theory of evolution known as the theory of Lamarckism.
It was Lamarck who first believed that elephants earlier had small trunks. But eventual when there was scarcity of food and water, the elephants stretched out its trunk to reached out for food such as trees and also water. And as a result their offspring inherited long and powerful trunk.
In his theory of Lamarckism, he believed that the species passes on its traits to the offspring which they acquired through their use in their lifetime. In this case, the elephants might have used their trunks in such a way that they became long and strong over time and they passed tis trait to their babies.
Answer:
mRNA is “messenger” RNA. mRNA is synthesized in the nucleus using the nucleotide sequence of DNA as a template. This process requires nucleotide triphosphates as substrates and is catalyzed by the enzyme RNA polymerase II. The process of making mRNA from DNA is called transcription, and it occurs in the nucleus.
Answer:B
Explanation:
The circulatory system is made up of blood vessels that carry blood away from and towards the heart. Arteries carry blood away from the heart and veins carry blood back to the heart. The circulatory system carries oxygen, nutrients, and hormones to cells, and removes waste products, like carbon dioxide.
