What does it mean that some organisms are selected by the environment to survive and reproduce? natural selection What is a genetic characteristic that allows an organism to survive and reproduce? Key terms Term Meaning Adaptation A trait that improves an organism’s ability to survive and reproduce in an environment Fitness The ability of an […]

What is eutrophication explain with reference to aquatic ecosystem? Eutrophication (the overenrichment of aquatic ecosystems with nutrients leading to algal blooms and anoxic events) is a persistent condition of surface waters and a widespread environmental problem. This type of eutrophication is not reversible unless there are substantial changes in soil management. What happens when eutrophication […]

Which element forms an ionic compound when it reacts with lithium *? bromine What elements are most likely to form ionic compounds? The ions are held together by ionic bonds, which form an ionic compound. Ionic compounds generally form between elements that are metals and elements that are nonmetals. For example, the metal calcium (Ca) […]

What is the definition of dermal tissue? angiosperms. In angiosperm: Dermal tissue. The dermal tissue system—the epidermis—is the outer protective layer of the primary plant body (the roots, stems, leaves, flowers, fruits, and seeds). The epidermis is usually one cell layer thick, and its cells lack chloroplasts. What is dermal tissue responsible for? Dermal tissue […]

Are covalent bonds chemical reactions? When electrons redistribute their orbitals to include two or more atomic nuclei, as is the case in a covalent bond, or donate or accept electrons, as is the case in an ionic bond, a chemical reaction has occurred. Two general types of bonds form during chemical reactions: ionic and covalent. […]

In what parts of the brain does the majority of development occur between the ages of 3 to 6? frontal lobes How does the brain develop during childhood? Starting from birth, children develop brain connections through their everyday experiences. They’re built through positive interactions with their parents and caregivers and by using their senses to […]

What do T cells do in lymph nodes? Within lymph nodes, T cells can receive signals during both short-lived and long-lived interactions with antigen-bearing DCs. These contacts are highly regulated events that are influenced by the timing of activation, signal strength, the inflammatory environment and the presence of other responding T cells. Are T cells […]

Why do climate zones differ between continents even though locations are similar? A climate zone depends on a region’s latitude, continental position, and relationship to prevailing winds, large water bodies, and mountains, among other factors. The temperature, rainfall, length of dry season, and other features of the climate zone determine which plants can grow. Why […]

Why is a large animal made of small cells? Small cells are most efficient at taking up oxy- gen and nutrients from the environment. What is one reason multicellular organisms, such as people, are made up of many small cells instead of one large cell? Smaller cells have more surface area for oxygen and nutrients […]

What would be the best method for separating a mixture of salt and water? For example, water can be separated from salt solution by simple distillation. This method works because water has a much lower boiling point than salt. When the solution is heated, the water evaporates. It is then cooled and condensed into a […]