Answer the following question given this paragraph: 18.3 Erythrocytes The most abundant formed elements in blood, erythrocytes are red, biconcave disks packed with an oxygen-carrying compound called hemoglobin. The hemoglobin molecule contains four globin proteins bound to a pigment molecule called heme, which contains an ion of iron. In the bloodstream, iron picks up oxygen in the lungs and drops it off in the tissues; the amino acids in hemoglobin then transport carbon dioxide from the tissues back to the lungs. Erythrocytes live only 120 days on average, and thus must be continually replaced. Worn-out erythrocytes are phagocytized by macrophages and their hemoglobin is broken down. The breakdown products are recycled or removed as wastes: Globin is broken down into amino acids for synthesis of new proteins; iron is stored in the liver or spleen or used by the bone marrow for production of new erythrocytes; and the remnants of heme are converted into bilirubin, or other waste products that are taken up by the liver and excreted in the bile or removed by the kidneys. Anemia is a deficiency of RBCs or hemoglobin, whereas polycythemia is an excess of RBCs. Q: The most abundant formed elements in blood, erythrocytes are red, biconcave disks packed with an oxygen-carrying compound called this? Choices: - plasma - hydrogen - pus - hemoglobin A:
hemoglobin
(Question)
Answer the following question given this paragraph: Upon fertilization a diploid zygote is formed. In humans, a zygote has 46 chromosomes, 23 inherited from each parent. The gametes, sperm and eggs, are haploid cells, with 23 chromosomes each. Q: In humans, a zygote has how many chromosomes? Choices: - 36 - 42 - 23 - 46 A:
(Answer)
46
Ques: Answer the following question given this paragraph: After a star becomes a red giant, it will take one of several different paths to end its life. Which path is followed by a star after the red giant phase depends on its mass. During the fusion life of a star, its size is the result of a competition between fusion heat pushing the material out and gravity pulling the material in. At the end, gravity always wins. After the star has lived through its red giant stage, the fusion essentially ends (the star runs out of fuel) allowing gravity to collapse the star. Some of the outer layers of material will be blown away and the core becomes smaller and denser. The core will become either a neutron star, a white dwarf, a black dwarf, or a black hole. Q: After what life stage does the fusion inside a star end? Choices: - blue giant - yellow dwarf - white dwarf - red giant A:
Ans: red giant
(Q).
Answer the following question given this paragraph: Renewable energy resources include solar, water, wind, biomass, and geothermal power. These resources are usually replaced at the same rate that we use them. Scientists know that the Sun will continue to shine for billions of years. So we can use the solar energy without it ever running out. Water flows from high places to lower ones. Wind blows from areas of high pressure to areas of low pressure. We can use the flow of wind and water to generate power. We can count on wind and water to continue to flow! Burning wood ( Figure below ), is an example of biomass energy. Changing grains into biofuels is biomass energy. Biomass is renewable because we can plant new trees or crops to replace the ones we use. Geothermal energy uses water that was heated by hot rocks. There are always more hot rocks available to heat more water. Q: Biomass, solar, wind, water, and geothermal power are examples of what kinds of energy resources? Choices: - mechanical - electrical - fossil fuel - renewable A:
(A).
renewable
Ques:Answer the following question given this paragraph: Prevailing winds are the result of atmospheric circulation cells. They influence the climate of a region. Q: What do prevailing winds influence? Choices: - weather - temperature - barometric pressure - climate A:

Ans:climate
Ques:Answer the following question given this paragraph: As we view the land around us we see landforms. Landforms are physical features on Earth's surface. Landforms are introduced in this section but will be discussed more in later chapters. Constructive forces cause landforms to grow. Lava flowing into the ocean can build land outward. A volcano can be a constructive force. Destructive forces may blow landforms apart. A volcano blowing its top off is a destructive force. The destructive forces of weathering and erosion change landforms more slowly. Over millions of years, mountains are worn down by rivers and streams. Q: Physical features on the earth's surface are known as ______ Choices: - atmospheres - diversity - biospheres - landforms A:

Ans:
landforms