Answer the following question given this paragraph: 37.2 | How Hormones Work By the end of this section, you will be able to: Explain how hormones work Discuss the role of different types of hormone receptors Hormones mediate changes in target cells by binding to specific hormone receptors. In this way, even though hormones circulate throughout the body and come into contact with many different cell types, they only affect cells that possess the necessary receptors. Receptors for a specific hormone may be found on many different cells or may be limited to a small number of specialized cells. For example, thyroid hormones act on many different tissue types, stimulating metabolic activity throughout the body. Cells can have many receptors for the same hormone but often also possess receptors for different types of hormones. The number of receptors that respond to a hormone determines the cell's sensitivity to that hormone, and the resulting cellular response. Additionally, the number of receptors that respond to a hormone can change over time, resulting in increased or decreased cell sensitivity. In up-regulation, the number of receptors increases in response to rising hormone levels, making the cell more sensitive to the hormone and allowing for more cellular activity. When the number of receptors decreases in response to rising hormone levels, called down-regulation, cellular activity is reduced. Receptor binding alters cellular activity and results in an increase or decrease in normal body processes. Depending on the location of the protein receptor on the target cell and the chemical structure of the hormone, hormones can mediate changes directly by binding to intracellular hormone receptors and modulating gene transcription, or indirectly by binding to cell surface receptors and stimulating signaling pathways. Q: What biochemicals mediate changes in target cells by binding to specific receptors? Choices: - amino acids - acids - enzymes - hormones A:
hormones
Answer the following question given this paragraph: A spectrometer produces a spectrum from starlight. Astronomers can learn a lot about a star by studying its spectrum. Q: What is a spectrometer able to produce from starlight? Choices: - radio waves - exposure - aspect - spectrum A:
spectrum
Q: Answer the following question given this paragraph: Water power does not burn a fuel. So it causes less pollution than many other kinds of energy. Water power is also a renewable resource. Water keeps flowing downhill. Although we use some of the energy from this movement, we are not using up the water. Q: What type of resource is water power? Choices: - biological - nonrenewable - geothermal - renewable A:
A: renewable
Question: Answer the following question given this paragraph: Gyroscopes used in guidance systems to indicate directions in space must have an angular momentum that does not change in direction. Yet they are often subjected to large forces and accelerations. How can the direction of their angular momentum be constant when they are accelerated?. Q: What instruments used in guidance systems to indicate directions in space must have an angular momentum that does not change in direction? Choices: - actuators - elevators - magnets - gyroscopes A:
Answer: gyroscopes
*Question*
Answer the following question given this paragraph: Most plant cells have a large central vacuole . It can make up as much as 90 percent of a plant cell's total volume. The central vacuole is like a large storage container. It may store substances such as water, enzymes, and salts. It may have other roles as well. For example, the central vacuole helps stems and leaves hold their shape. It may also contain pigments that give flowers their colors. Q: Most plant cells have a large central what? Choices: - nuclei - loci - membranes - vacuole A:
**Answer**
vacuole
*Question*
Answer the following question given this paragraph: The mother's mammary glands go through changes during the third trimester to prepare for lactation and breastfeeding. When the baby begins suckling at the breast, signals are sent to the hypothalamus causing the release of prolactin from the anterior pituitary. Prolactin causes the mammary glands to produce milk. Oxytocin is also released, promoting the release of the milk. The milk contains nutrients for the baby's development and growth as well as immunoglobulins to protect the child from bacterial and viral infections. Q: Human mammary glands can produce what substance, which can be used to feed children? Choices: - edema - urea - sperm - milk A:
**Answer**
milk