21. The difference between autotroph and heterotroph is that
a. heterotrophs must get energy from sources other than the sun
b. heterotrophs can use chemical or light energy sources
c. heterotrophs do not obtain energy from autotrophs
d. all of the above
A?
25. Which of the following is NOT true for the cellular respiration process?
a. The total amount of ATP that a cell gains for each glucose molecule that enters glycolysis depends on the presence of carbon dioxide
b. Pyruvate produced during glycolysis enters a mitochondrian during the second stage of cellular respiration
c. The final electron acceptor in aerobic respiration is oxygen
d. Acetyl-CoA combines with a four-carbon molecule
A?
28. The structure of chromosomes is best explained as DNA
a. broken apart into separate genes
b. extended to form very long, thin molecules
c. wrapped tightly around associated proteins
d. coiled up into a ball
I'm stuck between C and D
29. A normal, healthy human offspring develops when
a. an X chromosome is donated by each parent
b. a change in the chromosome number occurs
c. the structure of a chromosome is changed by mutation
d. none of the above
D?
Thanks
-MC
21. To determine the difference between autotrophs and heterotrophs, we need to evaluate the statements given in the options.
a. Heterotrophs must get energy from sources other than the sun. This statement is true. Heterotrophs are unable to produce their own food through photosynthesis and therefore rely on external sources for energy.
b. Heterotrophs can use chemical or light energy sources. This statement is also true. Heterotrophs can obtain energy both from consuming other organisms (chemical energy) and from sunlight indirectly through the consumption of autotrophs (light energy).
c. Heterotrophs do not obtain energy from autotrophs. This statement is false. Heterotrophs can obtain energy from autotrophs by consuming them.
Considering the above, the correct statement would be d. all of the above. Heterotrophs must get energy from sources other than the sun, they can use chemical or light energy sources, and they can obtain energy from autotrophs through consumption.
25. Let's evaluate the statements given in the options to determine which one is not true for the cellular respiration process.
a. The total amount of ATP that a cell gains for each glucose molecule that enters glycolysis depends on the presence of carbon dioxide. This statement is false. The presence of carbon dioxide does not directly affect the total amount of ATP gained during cellular respiration.
b. Pyruvate produced during glycolysis enters a mitochondrion during the second stage of cellular respiration. This statement is true. Pyruvate generated from glycolysis enters the mitochondrion where it undergoes further processes in the citric acid cycle.
c. The final electron acceptor in aerobic respiration is oxygen. This statement is true. Oxygen serves as the final electron acceptor in the electron transport chain during aerobic respiration.
d. Acetyl-CoA combines with a four-carbon molecule. This statement is also true. Acetyl-CoA combines with oxaloacetate, a four-carbon molecule, to start the citric acid cycle.
Considering the above, the statement that is not true for the cellular respiration process is a. The total amount of ATP that a cell gains for each glucose molecule that enters glycolysis depends on the presence of carbon dioxide.
28. To determine the best explanation for the structure of chromosomes, we need to evaluate the options provided.
a. DNA broken apart into separate genes. This is not an accurate explanation of chromosome structure. While genes are segments of DNA within chromosomes, chromosomes contain more than just genes.
b. DNA extended to form very long, thin molecules. This is partly true. Chromosomes are formed by DNA molecules that are tightly coiled and condensed, making them appear as long, thin structures.
c. DNA wrapped tightly around associated proteins. This statement is true. Chromosomes consist of DNA strands that are tightly wrapped around proteins called histones. This organization helps to compact the DNA and protect it.
d. DNA coiled up into a ball. This explanation does not accurately describe the structure of chromosomes. While chromosomes are highly coiled and condensed, they do not form a spherical ball-like structure.
Considering the above, the best explanation for the structure of chromosomes is c. DNA wrapped tightly around associated proteins.
29. To determine what happens during the development of a normal, healthy human offspring, we need to evaluate the options provided.
a. An X chromosome is donated by each parent. This statement is true. In a normal human offspring, one sex chromosome is inherited from each parent, resulting in a pair of sex chromosomes (XX in females and XY in males).
b. A change in the chromosome number occurs. This statement is false. In a normal, healthy human offspring, the chromosome number remains constant. Any changes in chromosome number, such as aneuploidy or chromosomal abnormalities, would not result in a normal offspring.
c. The structure of a chromosome is changed by mutation. This statement is false. Mutations can occur in individual genes, but in a normal offspring, the overall structure of chromosomes remains intact.
Considering the above, the correct statement is d. none of the above.