2025 Biology Regents Practice 1

In the mid 1990s, people across several states, including Minnesota and Wisconsin, were finding large numbers of frogs and other amphibians with extra limbs. Scientists were stumped over the cause of the deformities. Theories regarding the possible cause of these abnormalities ranged from UV radiation, chemical contaminants in the water, parasites, or even airborne substances.

Which question could be asked to determine if the abnormalities seen in the frog legs were caused by an inherited mutation?

• Do the offspring with an abnormality live in the same environment as the parents?

• Were the parents exposed to the same environmental factors as their offspring?

• Is the mutation that causes abnormal legs present in the DNA of the sex cells of the parents?

• Do the cells within the legs of the parents contain DNA with the mutation that causes abnormal limbs?

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NGSS.HS-LS3-1

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A group of scientists are investigating the process of de-extinction, the production of an organism belonging to an extinct species. Wooly mammoth populations in North America peaked about 10,000 years ago, during the last ice age. The reasons behind its extinction are not completely clear, but a warming climate, retreat of the glaciers, and hunting all likely contributed to their demise. They have been targeted for de-extinction in part because they went extinct relatively recently and samples of mammoth tissues are available to provide DNA

Based on the information given, select the statement that supports a claim regarding which modern elephant would be the best surrogate to carry a mammoth embryo.

• The Asian elephant because they weigh the same at birth and have some similar structural characteristics

• The Asian elephant because its number of chromosomes is closest to the woolly mammoth's chromosome number

• The African elephant because it is most likely stronger and larger so it would more easily carry a woolly mammoth embryo

• The African elephant because it has long tusk on a smaller head like the woolly mammoth.

The scientists hope to produce embryos that include mammoth DNA through cloning. Females selected from the closest living relatives of the mammoth would carry the embryo thought birth.

Use specific information from the model to describe why the cells of the embryo and the resulting "de-extinct" mammoth would be expected to have the same genetic content as the extinct donor mammoth.

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NGSS.HS-LS3-1

NGSS.HS-LS3-2

Cancer is the result of uncontrolled cell division in body cells, possibly leading to an irregular mass known as a tumor. The presence of tumors may affect normal functioning of the body's organ systems.

Using the model, which claim can be made that describes an effect of genetic changes on the process of mitosis?

• The genetic changes result in abnormal meiotic division that produce daughter cells with double the chromosome number as the original cell.

• The genetic changes have no effect on the cells' ability to control mitotic cell division and cause the formation of malignant tumors.

• The genetic changes cause the normal cells to lose control of mitosis and cause tumor formation

• The genetic changes cause the daughter cells to lose control of meiosis and produce malignant tumors.

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NGSS.HS-LS1-4

Stem cells are being researched as a potential treatment for some forms of cancer. Stem cells can develop into many different types of cells in the body.

Complete the model below to explain how a single stem cell can become a neuron or epithelial cell

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NGSS.HS-LS1-4

Based on the model, why would researchers be interested in treatments that cause tumor cells to enter a "sleeping state"?

• Tumor cells that enter the "sleeping state" will continue to divide and complete the life cycle until they die

• Tumor cells will complete fewer cell divisions during their life cycle and will be smaller than other non-tumor cells

• Tumor cells that enter the "sleeping state" are more likely to become differentiated and form healthy nerve tissue.

• Tumor cells that enter the "sleeping state" during their life cycle would be less likely to divide

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NGSS.HS-LS1-4

In the study of genetic mutations, researchers often look for patterns in the DNA sequences of affected individuals. What question could help determine if a specific mutation is responsible for a genetic disorder?

• Is the mutation found in all individuals with the disorder?

• Do individuals without the disorder also have the mutation?

• Is the mutation present in the DNA of the parents of affected individuals?

• Does the mutation occur more frequently in one gender?

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NGSS.HS-LS3-2

When considering the impact of environmental factors on genetic expression, which question would be most relevant to investigate?

• Do environmental factors affect all organisms in the same way?

• Do environmental factors alter the DNA sequence of an organism?

• Can environmental factors influence the expression of certain genes without changing the DNA sequence?

• Are environmental factors more influential than genetic factors in determining an organism's traits?