Answer: some energy is lost from the pyramid, energy is transferred from bottom (producers) to top, but in decreasing amounts.
Explanation: total energy is conserved, but not necessarily within the energy pyramid, which is an open system where energy is lost from the pyramid, mainly as heat but also as sound.
Energy is transferred up the pyramid but the amount transferred at each stage is less because of losses outside the pyramid.
Answer:
Deforestation and the burning of fossil fuels
Explanation:
Deforestation leads to less carbon dioxide to oxygen production, and burning fossil fuels releases large amounts of carbon dioxide.
Answer:
Yes, two hydrogen bonds could form between thymine and cytosine.
Explanation:
Cytosine is a pyrimidine base found in both DNA and RNA, and Thymine is a pyrimidine base found in only DNA. Electronegative Oxygen and Nitrogen atoms with free lone pairs are potential hydrogen bond acceptors. Hydrogen atoms attached to very electronegative atoms like Oxygen and Nitrogen have strong partial positive charge and are potential hydrogen bond donors.
One hydrogen bond could form between the C4 carbonyl group on thymine which is a hydrogen bond acceptor and the C4 amino group on cytosine which is a hydrogen bond donor. Also, another hydrogen bond could be formed between N3 of thymine which is a hydrogen bond donor and the N3 of cytosine that is a hydrogen bond acceptor.
It is important to note that hydrogen bond cannot be formed between them because the C2 carbonyl groups found on both bases are both hydrogen bond acceptors.
The correct answer is option (B) continental drift.
Continental drift is a theory explaining the movement of the earth’s continents over the geological time scale, drifting across the ocean bed. It was proposed by Alfred Wegener in 1912. Similar plants and animal fossils found around the shores of the different continents suggests that these continents were once joined as a single super continent named Pangaea. This Pangaea broke up long ago and the continents moved to their current positions. The ancient fossils of the same species of plants and animals were found on rocks of the same age but on the continents that are now widely separated.
Green plants remove carbon dioxide from the atmosphere by photosynthesis.
