Answer:
Both are true; the second is part of the cell theory.
According to Chargaff's rule, pyrimidine and purine occur in equal ration (1:1) in the DNA of all cells. Adenine (A) and Thymine (T) occur in equal proportion while Guanine (G) and Cytosine (C) occurs in equal proportion in the DNA of an organism. This pattern is repetitive and found in both DNA strands.
Ecosystems have trouble adjusting to short-term changes - This is false.
Eco system changes can be long term and short term. Few short-term environmental changes that can change an eco system are - drought, smog, volcanic eruptions, floods etc. An ecosystem can easily adapt to short-term changes. For example, after a forest fire plants can re-grow from their roots. Many species have features to help them cope with natural, short-term environmental changes.
Enzymes can be denatured by:
1) pH Levels
2) Temperature levels
3) Enzyme inhibitor Presence
4) Substrate Concentration
Hope this helps!
Humans can respire aerobically and anaerobically. Pyruvate and ATP are products both aerobic cell respiration and anaerobic cell respiration in Humans.
