Reporting Category Biology

Scientists determined the total mass of DNA from a sample of animal cells. The masses of equal numbers of cells were taken during three different stages of the cell cycle. Stage I contains cells massed during G1 of the cell cycle. Which statement best describes the cells during Stage II?

• The cells have replicated their DNA, but have not completed mitosis and cytokinesis.

• The cells have completed mitosis and cytokinesis without replicating their DNA.

• The cells have replicated their DNA and completed mitosis and cytokinesis.

• The cells have temporarily exited the cell cycle without replicating their DNA.

Answer explanation

During Stage II, the cells have replicated their DNA, but have not completed mitosis and cytokinesis. Therefore, the mass of DNA is double the mass of the DNA in stages I and III.

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NGSS.HS-LS1-4

Which type of movement across a cell's plasma membrane requires energy supplied by ATP?

• Passive Transport

• Simple Diffusion

• Active Transport

• Osmosis

Answer explanation

Active transport requires cellular energy, which is supplied by ATP.

Which characteristic best distinguishes these cells as either prokaryotic or eukaryotic?

• The organization of the genetic material

• The location of the cytoplasm

• The role of the cell membrane

• The function of the flagella

Answer explanation

The organization of the genetic material is the best characteristic to distinguish these cells as either prokaryotic or eukaryotic.

The graph shows the oxygen consumed by an athlete during different stages of training.

Based on the graph, which process is occurring between minute 5 and minute 10?

• Nuclei are building amino acids for energy storage.

• Ribosomes are building carbohydrates to increase energy output.

• Chloroplasts are using energy to produce oxygen.

• Mitochondria are using oxygen to produce ATP.

Answer explanation

Mitochondria produce energy for cells. The increase in the consumption of oxygen between 5 and 10 minutes is due to mitochondria using oxygen to produce ATP.

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NGSS.HS-LS1-7

NGSS.HS-LS2-3

Normal cells that have a contact inhibition feedback mechanism that prevents the cells from replicating when other cells are touched. A diagram of cells with contact inhibition and cells without contact inhibition is shown. Which statement best describes what will happen to cells in an organism that lack contact inhibition?

• The cells will continue to grow, causing a tumor in the body.

• The cells will replicate normally, replacing body cells that die.

• The cells will replicate until the food supply for each cell is used, causing each cell to die.

• The cells will stop replicating once one layer is produced, as other body cells will crowd them out.

Answer explanation

Contact inhibition is a mechanism that stops the cell cycle and prevents cells from performing replication/proliferation and growth. The cells in an organism that lack contact inhibition will continue to replicate/proliferate and grow, and potentially lead to the development of tumors.

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NGSS.HS-LS1-3

Which sample most likely contains viruses?

• Sample 1

• Sample 2

• Sample 3

• Sample 4

Answer explanation

Sample 3 is a virus due to the absence of organelles and the presence of a small genome.

Which model accurately shows a cell progressing through Mitosis?

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Answer explanation

The stages of mitosis (prophase, metaphase, anaphase, and telophase) are in the correct sequence based on the model shown.

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NGSS.HS-LS1-4

Which table best compares the events that occur during different stages of the cell cycle?

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Answer explanation

DNA replication occurs during the S phase. Nuclear division occurs during the M phase.

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NGSS.HS-LS1-4

Which of these shows an example of an insertion mutation?

• A

• B

• C

• D

Answer explanation

An insertion mutation is a result of inserting new nitrogenous bases into DNA. In this model, new “K” and “L” genes have been inserted into the chromosome.

Tags

NGSS.HS-LS3-2

A model of the genetic control of coat color in rabbits is shown.

Which Punnett square represents a cross that would produce albino offspring?

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Answer explanation

The albino allele (c) is recessive to all other alleles, so expression of the albino phenotype requires two copies of the allele. This option is the only option where two albino alleles would result.

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NGSS.HS-LS3-1

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