Answer the following question given this paragraph: The mechanical advantage of a machine is related to how it changes force. Explain this relationship. Q: The mechanical advantage of a machine is related to how it changes what? Choices: - pressure - nature - example - force A:
force
Answer the following question given this paragraph: Acids are substances that provide hydrogen ions (H+) and lower pH, whereas bases provide hydroxide ions (OH) and raise pH. The stronger the acid, the more readily it donates H+. For example, hydrochloric acid and lemon juice are very acidic and readily give up H+ when added to water. Conversely, bases are those substances that readily donate OH. The OH ions combine with H+ to produce water, which raises a substance's pH. Sodium hydroxide and many household cleaners are very alkaline and give up OH rapidly when placed in water, thereby raising the pH. Most cells in our bodies operate within a very narrow window of the pH scale, typically ranging only from 7.2 to 7.6. If the pH of the body is outside of this range, the respiratory system malfunctions, as do other organs in the body. Cells no longer function properly, and proteins will break down. Deviation outside of the pH range can induce coma or even cause death. So how is it that we can ingest or inhale acidic or basic substances and not die? Buffers are the key. Buffers readily absorb excess H+ or OH, keeping the pH of the body carefully maintained in the aforementioned narrow range. Carbon dioxide is part of a prominent buffer system in the human body; it keeps the pH within the proper range. This buffer system involves carbonic acid (H2CO3) and bicarbonate (HCO3) anion. If too much H+ enters the body, bicarbonate will combine with the H+ to create carbonic acid and limit the decrease in pH. Likewise, if too much OH is introduced into the system, carbonic acid will rapidly dissociate into bicarbonate and H+ ions. The H+ ions can combine with the OH ions, limiting the increase in pH. While carbonic acid is an important product in this reaction, its presence is fleeting because the carbonic acid is released from the body as carbon dioxide gas each time we breathe. Without this buffer system, the pH in our bodies would fluctuate too much and we would fail to survive. Q: What are substances that provide hydrogen ions (h+) and lower ph? Choices: - proteins - nutrients - bases - acids A:
acids
Q: Answer the following question given this paragraph: Like all living things, plants detect and respond to stimuli in their environment. Unlike animals, plants can't run, fly, or swim toward food or away from danger. They are usually rooted firmly in the soil, like the tree in Figure below . Q: Where are most plants firmly rooted? Choices: - rock - grass - mineral - soil A:
A: soil
Question: Answer the following question given this paragraph: Neutron stars are the corpses of stars left over after supernova explosions. They are the size of a small city, but can spin several times per second. (Try to imagine this in your head. ) Consider a neutron star of radius 10 km that spins with a period of 0.8 seconds. Imagine a person is standing at the equator of this neutron star. Calculate the centripetal acceleration of this person and compare it to the acceleration due to gravity on Earth. Q: Neutron stars are the corpses of left over what? Choices: - planet explosions - gravitational explosions - stellar explosions - supernova explosions A:
Answer: supernova explosions
*Question*
Answer the following question given this paragraph: CHAPTER SUMMARY 11.1 Discovering How Populations Change Evolution by natural selection arises from three conditions: individuals within a species vary, some of those variations are heritable, and organisms have more offspring than resources can support. The consequence is that individuals with relatively advantageous variations will be more likely to survive and have higher reproductive rates than those individuals with different traits. The advantageous traits will be passed on to offspring in greater proportion. Thus, the trait will have higher representation in the next and subsequent generations leading to genetic change in the population. The modern synthesis of evolutionary theory grew out of the reconciliation of Darwin's, Wallace's, and Mendel's thoughts on evolution and heredity. Population genetics is a theoretical framework for describing evolutionary change in populations through the change in allele frequencies. Population genetics defines evolution as a change in allele frequency over generations. In the absence of evolutionary forces allele frequencies will not change in a population; this is known as Hardy-Weinberg equilibrium principle. However, in all populations, mutation, natural selection, genetic drift, and migration act to change allele frequencies. Q: What is the term for a theoretical framework for describing evolutionary change in populations through the change in allele frequencies? Choices: - percent genetics - density genetics - total genetics - population genetics A:
**Answer**
population genetics
(Question)
Answer the following question given this paragraph: Consumers take in food by eating producers or other living things. Q: What members of an ecosystem food chain take in food by eating producers or other living things? Choices: - primary producers - decomposers - insectivores - consumers A:
(Answer)
consumers