Plants use sunlight, soil, and water to grow. Animals use leaves, branches, trees, or soil for shelter and other living things for food. These are examples of interactions of biotic and abiotic elements in ecosystems. In a pond, the plants, soil, and water create suitable habitat for many different birds, insects, and fish. Other animals, such as bears, eat fish and berries. Feeding interactions give living things the nutrients they need to survive.
A. external
These types of signals are observed when there is a cut on the body. The epidermal cells lose contact with one another and divide faster until they are in contact once again. After they come into contact, division slows down again.
Answer:
e. 1/2; semiconservative
Explanation:
1/2 (proportion) of DNA molecules (each molecule is double stranded not single stranded) will contain any radioactivity after two rounds of replication.
This experiment also demonstrates that replication is semiconservative
.
DNA replication is semi-conservative because each helix that is created contains, one strand from the helix from which it was copied.