Answer the following question given this paragraph: The first horizon is the "A" horizon. It is more commonly called the topsoil . The topsoil is usually the darkest layer of the soil. It is the layer with the most organic material. Humus forms from all the plant and animal debris that falls to or grows on the ground. The topsoil is also the region with the most biological activity. Many organisms live within this layer. Plant roots stretch down into this layer. The roots help to hold the topsoil in place. Topsoil is needed to grow most crops ( Figure below ). Q: What is the "a" horizon commonly known as? Choices: - sediment - core - crust - topsoil A:
topsoil
(Question)
Answer the following question given this paragraph: The kidneys help the body maintain homeostasis in several ways. They filter all the blood in the body many times each day and produce urine. They control the amount of water and dissolved substances in the blood by excreting more or less of them in urine. Q: Which body organ filters the blood in the body and creates urine? Choices: - intestines - liver - the arteries - the kidneys A:
(Answer)
the kidneys
Ques: Answer the following question given this paragraph: Active transport pumps can also work together with other active or passive transport systems to move substances across the membrane. For example, the sodium-potassium pump maintains a high concentration of sodium ions outside of the cell. Therefore, if the cell needs sodium ions, all it has to do is open a passive sodium channel, as the concentration gradient of the sodium ions will drive them to diffuse into the cell. In this way, the action of an active transport pump (the sodiumpotassium pump) powers the passive transport of sodium ions by creating a concentration gradient. When active transport powers the transport of another substance in this way, it is called secondary active transport. Symporters are secondary active transporters that move two substances in the same direction. For example, the sodiumglucose symporter uses sodium ions to "pull" glucose molecules into the cell. Because cells store glucose for energy, glucose is typically at a higher concentration inside of the cell than outside. However, due to the action of the sodiumpotassium pump, sodium ions will easily diffuse into the cell when the symporter is opened. The flood of sodium ions through the symporter provides the energy that allows glucose to move through the symporter and into the cell, against its concentration gradient. Q: The flood of sodium ions through the symporter provides the energy that allows what to move through the symporter and into the cell? Choices: - insulin - sucrose - mitochondria - glucose A:
Ans: glucose
(Q).
Answer the following question given this paragraph: Q: From what did the first proto-oncogenes arise? Choices: - spores - carcinogens - bacteria - viral infections A:
(A).
viral infections
Ques:Answer the following question given this paragraph: 21.5 | The Immune Response against Pathogens By the end of this section, you will be able to: Explain the development of immunological competence Describe the mucosal immune response Discuss immune responses against bacterial, viral, fungal, and animal pathogens Describe different ways pathogens evade immune responses Now that you understand the development of mature, naive B cells and T cells, and some of their major functions, how do all of these various cells, proteins, and cytokines come together to actually resolve an infection? Ideally, the immune response will rid the body of a pathogen entirely. The adaptive immune response, with its rapid clonal expansion, is well suited to this purpose. Think of a primary infection as a race between the pathogen and the immune system. The pathogen bypasses barrier defenses and starts multiplying in the host's body. During the first 4 to 5 days, the innate immune response will partially control, but not stop, pathogen growth. As the adaptive immune response gears up, however, it will begin to clear the pathogen from the body, while at the same time becoming stronger and stronger. When following antibody responses in patients with a particular disease such as a virus, this clearance is referred to as seroconversion (sero- = "serum"). Seroconversion is the reciprocal relationship between virus levels in the blood and antibody levels. As the antibody levels rise, the virus levels decline, and this is a sign that the immune response is being at least partially effective (partially, because in many diseases, seroconversion does not necessarily mean a patient is getting well). An excellent example of this is seroconversion during HIV disease (Figure 21.26). Notice that antibodies are made early in this disease, and the increase in anti-HIV antibodies correlates with a decrease in detectable virus in the blood. Although these antibodies are an important marker for diagnosing the disease, they are not sufficient to completely clear the virus. Several years later, the... Q: What bodily system is primarily responsible for fighting pathogens in the body? Choices: - digestion - Cardiovascular - Muscular - immune A:

Ans:immune
Ques:Answer the following question given this paragraph: Most groundwater does not flow out of an aquifer as a spring or geyser. So to use the water that's stored in an aquifer, people must go after it. How? They dig a well. A well ( Figure below ) is a hole that is dug or drilled through the ground down to an aquifer. Q: What is a hole that is dug or drilled through the ground down to an aquifer called? Choices: - moat - ditch - canal - well A:

Ans:
well