Why are circulatory systems unnecessary for organisms with gastrovascular cavities?
A) they do have circulatory systems, they are just smaller and less complex
B) they don't use oxygen
C) diffusion is unnecessary
D) all cells are near the external environment, so diffusion alone is sufficient
Answer: D) all cells are near the external environment, so diffusion alone is sufficient
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Biology
- The osmoregulatory/excretory system of a freshwater flatworm is based on the operation of _____.
- Materials are returned to the blood from the filtrate by which of the following processes?
- Excretory organs known as Malpighian tubules are present in _____.
- The production of antibodies
- The end product of thymine degradation is _______.
- All of the following are directly involved in protein turnover except _______.
- Components of the transulfuration pathway include all of the following except _____.
- Homogentisate is an intermediate in the degradation of __________.
- Amino acids whose degradation yields a-ketoglutarate include all of the following except _________.
- Amino acids whose degradation yields succinyl-CoA includes all of the following except ________.
- Which of the following reactions require SAM?
- One type of wax we discussed is used to protect your car. Name that wax
- Amino acids whose degradation yields acetyl-CoA include all of the following except ________.
- All of the following are referred to collectively as the branched chain amino acids except _________.
- The fixation of nitrogen requires _______.
- Asparagine is formed from aspartic acid and _________ .
- The oxidation state of the methenyl group (-CH=) is comparable to that of ____.
- All of the following are directly involved in the synthesis of deoxyribonucleic acid except _______.
- One-carbon carriers in metabolism include
- Extra Question) Which of the following is an a-keto acid/a-amino acid pair used in transamination?
- The conversion of phosphatidylethanolamine to phosphatidylcholine requires ______
- Chorismate is a precursor in the synthesis of all of the following except _______.
- SAM is a methyl donor in the synthesis of ______.
- The tranport of GSH out of cells serves all of the following functions except ______.
- All of the following are purine bases except _____.