When would a cell most likely contain the most nucleotides?
A. S
B. G1
C. M
D. G2
A cell copies its DNA during the S phase, and nucleotides are the building blocks of DNA. Thus, the step preceding the S phase, the G1 phase, is the phase of the cell cycle when the cell would contain the most nucleotides.
For a cell to divide into more cells, it must grow, copy its DNA, and produce new daughter cells. The cell cycle regulates cellular division. This process can either prevent a cell from dividing or trigger it to start dividing.
The cell cycle is an organized process divided into two phases: interphase and the M (mitotic) phase. During interphase, the cell grows and copies its DNA. After the cell reaches the M phase, division of the two new cells can occur. The G1, S, and G2 phases make up interphase.
- G1: The first gap phase, during which the cell prepares to copy its DNA
- S: The synthesis phase, during which DNA is copied
- G2 : The second gap phase, during which the cell prepares for cell division
It may appear that little is happening in the cell during the gap phases. Most of the activity occurs at the level of enzymes and macromolecules. The cell produces things like nucleotides for synthesizing new DNA strands, enzymes for copying the DNA, and tubulin proteins for building the mitotic spindle. During the S phase, the DNA in the cell doubles, but few other signs are obvious under the microscope. All the dramatic events that can be seen under a microscope occur during the M phase: the chromosomes move, and the cell splits into two new cells with identical nuclei.
Therefore, the Correct Answer is B.
More Questions on TEAS 7 Science
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Q #1: What is the correct order of the stages of the cell cycle?
A. G1,S,G2,M
B. G2,S,G1,M
C. M,S,G2,G1
D. S,M,G1,G1
Answer Explanation
The cell cycle is an organized process divided into two phases: interphase and the M (mitotic) phase. During interphase, the cell grows and copies its DNA. After the cell reaches the M phase, division of the two new cells can occur. The G1, S, and G2 phases make up interphase.
- G1: The first gap phase, during which the cell prepares to copy its DNA
- S: The synthesis phase, during which DNA is copied
- G2 : The second gap phase, during which the cell prepares for cell division
It may appear that little is happening in the cell during the gap phases. Most of the activity occurs at the level of enzymes and macromolecules. The cell produces things like nucleotides for synthesizing new DNA strands, enzymes for copying the DNA, and tubulin proteins for building the mitotic spindle. During the S phase, the DNA in the cell doubles, but few other signs are obvious under the microscope. All the dramatic events that can be seen under a microscope occur during the M phase: the chromosomes move, and the cell splits into two new cells with identical nuclei.
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Q #2: Which is true regarding the Urinary system?
A. Kidneys makes urine, Kidney help regulate water balance.
B. As a person ages, kidney tissue and filtration capacity increase, Regulates levels of electrolytes such as sodium and potassium.
C. Eliminates metabolic wastes., Kidneys makes urine., Kidney help regulate water balance.
D. Kidney help regulate water balance, Regulates levels of electrolytes such as sodium and potassium, Eliminates metabolic wastes
Answer Explanation
Kidneys makes urine is incorrect. Kidneys do not make urine. They help regulate water balance, regulate levels of electrolytes such as sodium and potassium, and eliminate metabolic wastes. Urine is a byproduct of these functions.
As a person ages, kidney tissue and filtration capacity increase is incorrect. As a person ages, the kidneys and bladder change. This can affect functions such as bladder control and how well the kidneys filter blood. Kidney changes range from a decrease in kidney tissue to decreased filtration capacity.
Kidneys help regulate water balance is correct. Kidneys help regulate water balance, regulate levels of electrolytes such as sodium and potassium, and eliminate metabolic wastes. Urine is a byproduct of these functions.
Regulates levels of electrolytes such as sodium and potassium is correct. There must be a continual balance of water and salt in the blood. The urinary system, specifically the kidneys, help maintain this balance. It also balances levels of metabolites or electrolytes such as sodium, potassium, and calcium.
Eliminates metabolic wastes is correct. Urea, creatinine, uric acid, and ammonium are the primary types of nitrogenous wastes excreted from the body. The urinary system also detects and excretes excess water from the blood and out of the body.
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Q #3: What raw inorganic material would an autotroph most likely use to create chemical energy for growth?
A. carbon dioxide
B. minerals in soil
C. decaying matter
D. sugar molecules
Answer Explanation
Autotrophs are organisms that use basic raw materials in nature, like the sun, to make energy-rich biomolecules. Minerals are naturally inorganic.
Autotrophs are organisms that make energy-rich biomolecules from raw material in nature. They do this by using basic energy sources such the sun. This explains why most autotrophs rely on photosynthesis to transform sunlight into usable food that can produce energy necessary for life. Plants and certain species of bacteria are autotrophs.
