Question: Q: Approximately how many billion years ago did our solar system begin? Read this paragraph and choose the correct option from the provided answers: Our solar system began about 5 billion years ago. The Sun, planets, and other solar system objects all formed at about the same time. The leading hypothesis for how they formed is called the nebular hypothesis . Choices: - four billion - three billion - nine billion - five billion A:
Answer: five billion

Question: Q: Cancer involves what changes that modify cell-cycle control and alter the growth rate or progression of the cell through the cell cycle? Read this paragraph and choose the correct option from the provided answers: 16.7 | Cancer and Gene Regulation By the end of this section, you will be able to: Describe how changes to gene expression can cause cancer Explain how changes to gene expression at different levels can disrupt the cell cycle Discuss how understanding regulation of gene expression can lead to better drug design Cancer is not a single disease but includes many different diseases. In cancer cells, mutations modify cell-cycle control and cells don't stop growing as they normally would. Mutations can also alter the growth rate or the progression of the cell through the cell cycle. One example of a gene modification that alters the growth rate is increased phosphorylation of cyclin B, a protein that controls the progression of a cell through the cell cycle and serves as a cell-cycle checkpoint protein. For cells to move through each phase of the cell cycle, the cell must pass through checkpoints. This ensures that the cell has properly completed the step and has not encountered any mutation that will alter its function. Many proteins, including cyclin B, control these checkpoints. The phosphorylation of cyclin B, a post-translational event, alters its function. As a result, cells can progress through the cell cycle unimpeded, even if mutations exist in the cell and its growth should be terminated. This post-translational change of cyclin B prevents it from controlling the cell cycle and contributes to the development of cancer. Choices: - deletions - enhancements - stabilization - mutations A:
Answer: mutations

Question: Q: In what type of body of water is most of the earth's water located? Read this paragraph and choose the correct option from the provided answers: Most of Earth's water is salt water in the oceans. As seen below, only 3 percent of Earth's water is fresh ( Figure below ). Freshwater is water that contains little or no dissolved salt. Most freshwater is frozen in ice caps and glaciers. Glaciers cover the peaks of some tall mountains. For example, the Cascades Mountains in North America and the Alps Mountains in Europe are capped with ice. Ice caps cover vast areas of Antarctica and Greenland. Chunks of ice frequently break off ice caps. They form icebergs that float in the oceans. Choices: - streams - rivers - seas - oceans A:
Answer:
oceans