Answer: We got it wrong when we checked off flooding. We are going with C) craters on surface. AND E) death of organisms and populations.
Explanation:
They occur in germ cell DNA, which are the cells that create sperm or Ova. For every 85 million nucleotides assembled in DNA during human sperm or Ova production, One will be a mutation
<u>Answer:</u>
The correct answer is Uracil which is nitrogen base found in RNA.
<u>Explanation:</u>
Uracil is a nitrogenous base which is located within an RNA molecule but not within a DNA molecule.
Uracil, represented by the letters A, G, C and U, is one of the four nucleobases that are found in the nucleic acid of RNA which binds to adenine.
While thymine is present in the DNA and binds to adenine.
Answer: c
Explanation: Plants and animals need nitrogen to make proteins but they cannot take it in from the air. Because nitrogen is unreactive as a gas, it has to be transformed into a new molecule. When bacteria in the soil takes nitrogen from the air, it becomes nitrates. Finally, it can move through the food chain in this form.
The question is incomplete. The complete question is:
Question: Why do organisms without oxygen need to convert pyruvate to lactate?
A) because pyruvate is toxic to the cells
B) in order to regenerate NAD+
C) in order to use lactate in the citric acid cycle
D) because lactate is needed to produce ATP
Answer:
B) in order to regenerate NAD+
Explanation:
Kreb's cycle and electron transport chain (ETC) are the aerobic stages of cellular respiration. ETC regenerates NAD+ and FAD+ by oxidation of NADH and FADH2 produced during glycolysis and Kreb's cycle. Here, oxygen serves as the terminal electron acceptor.
Glycolytic reactions use NAD+ as an electron acceptor and produce NADH. Therefore, a constant supply of NAD+ is required to sustain glycolysis. In absence of oxygen, ETC cannot occur and organisms convert pyruvate into lactate. Pyruvate is reduced in lactate and NADH serves as the electron donor. Thereby, lactate fermentation regenerates NAD+ to continue the process of glycolysis.
