Answer the following question given this paragraph: In addition to producing FSH and LH, the anterior portion of the pituitary gland also produces the hormone prolactin (PRL) in females. Prolactin stimulates the production of milk by the mammary glands following childbirth. Prolactin levels are regulated by the hypothalamic hormones prolactin-releasing hormone (PRH) and prolactin-inhibiting hormone (PIH), which is now known to be dopamine. PRH stimulates the release of prolactin and PIH inhibits it. The posterior pituitary releases the hormone oxytocin, which stimulates uterine contractions during childbirth. The uterine smooth muscles are not very sensitive to oxytocin until late in pregnancy when the number of oxytocin receptors in the uterus peaks. Stretching of tissues in the uterus and cervix stimulates oxytocin release during childbirth. Contractions increase in intensity as blood levels of oxytocin rise via a positive feedback mechanism until the birth is complete. Oxytocin also stimulates the contraction of myoepithelial cells around the milk-producing mammary glands. As these cells contract, milk is forced from the secretory alveoli into milk ducts and is ejected from the breasts in milk ejection ("let-down") reflex. Oxytocin release is stimulated by the suckling of an infant, which triggers the synthesis of oxytocin in the hypothalamus and its release into circulation at the posterior pituitary. Q: The posterior pituitary releases which hormone, which stimulates uterine contractions during childbirth? Choices: - estrogen - insulin - estradiol - oxytocin A:
oxytocin
Answer the following question given this paragraph: Greenhouse gases in the atmosphere absorb heat. This is called the greenhouse effect and it makes the planet warmer. Human actions have increased the greenhouse effect. Q: What has increased the greenhouse effect? Choices: - ozone depletion - temperature changes - climate change - human actions A:
human actions
Q: Answer the following question given this paragraph: Evolution that occurs over a long period of time is called macroevolution . It might take place over millions of years. This scale of evolution occurs above the level of the species. Fossils provide evidence for evolution at this scale. The evolution of the horse family, shown in Figure below , is an example of macroevolution. Q: What is evolution that occurs over a long period of time called? Choices: - spontaneous mutation - introgression - catabolism - macroevolution A:
A: macroevolution
Question: Answer the following question given this paragraph: Introduction Breathing is an involuntary event. How often a breath is taken and how much air is inhaled or exhaled are tightly regulated by the respiratory center in the brain. Humans, when they aren't exerting themselves, breathe approximately 15 times per minute on average. Canines, like the dog in Figure 39.1, have a respiratory rate of about 1530 breaths per minute. With every inhalation, air fills the lungs, and with every exhalation, air rushes back out. That air is doing more than just inflating and deflating the lungs in the chest cavity. The air contains oxygen that crosses the lung tissue, enters the bloodstream, and travels to organs and tissues. Oxygen (O2) enters the cells where it is used for metabolic reactions that produce ATP, a high-energy compound. At the same time, these reactions release carbon dioxide (CO2) as a by-product. CO2 is toxic and must be eliminated. Carbon dioxide exits the cells, enters the bloodstream, travels back to the lungs, and is expired out of the body during exhalation. Q: What gas is expired out of the body during exhalation? Choices: - carbon monoxide - hydrogen - oxygen - carbon dioxide A:
Answer: carbon dioxide
*Question*
Answer the following question given this paragraph: There are three types of mechanical waves. They differ in how they travel through a medium. The three types are transverse, longitudinal, and surface waves. All three types are described in detail below. Q: How many types of mechanical waves are there? Choices: - five - nine - one - three A:
**Answer**
three
(Question)
Answer the following question given this paragraph: Plastids are organelles in plant cells that may have various jobs. The main types of plastids are chloroplasts, chromoplasts, and leucoplasts. Q: Chloroplasts, chromoplasts, and leucoplasts are all plastids, organelles found in what kind of cells? Choices: - animal cells - lung cells - heart cells - plant cells A:
(Answer)
plant cells