Answer the following question given this paragraph: Variation and Adaptation Natural selection can only take place if there is variation, or differences, among individuals in a population. Importantly, these differences must have some genetic basis; otherwise, selection will not lead to change in the next generation. This is critical because variation among individuals can be caused by non-genetic reasons, such as an individual being taller because of better nutrition rather than different genes. Genetic diversity in a population comes from two main sources: mutation and sexual reproduction. Mutation, a change in DNA, is the ultimate source of new alleles or new genetic variation in any population. An individual that has a mutated gene might have a different trait than other individuals in the population. However, this is not always the case. A mutation can have one of three outcomes on the organisms' appearance (or phenotype):. Q: Genetic diversity in a population comes from two main sources - sexual reproduction and what else? Choices: - radiation - education - pathogen - mutation A:
mutation
(Question)
Answer the following question given this paragraph: Some samples of matter appear to have properties of solids, liquids, and/or gases at the same time. This can occur when the sample is composed of many small pieces. For example, we can pour sand as if it were a liquid because it is composed of many small grains of solid sand. Matter can also have properties of more than one state when it is a mixture, such as with clouds. Clouds appear to behave somewhat like gases, but they are actually mixtures of air (gas) and tiny particles of water (liquid or solid). The mass of an object is a measure of the amount of matter in it. One way to measure an object's mass is to measure the force it takes to accelerate the object. It takes much more force to accelerate a car than a bicycle because the car has much more mass. A more common way to determine the mass of an object is to use a balance to compare its mass with a standard mass. Although weight is related to mass, it is not the same thing. Weight refers to the force that gravity exerts on an object. This force is directly proportional to the mass of the object. The weight of an object changes as the force of gravity changes, but its mass does not. An astronaut's mass does not change just because she goes to the moon. But her weight on the moon is only one-sixth her earth-bound weight because the moon's gravity is only one-sixth that of the earth's. She may feel "weightless" during her trip when she experiences negligible external forces (gravitational or any other), although she is, of course, never "massless. " The law of conservation of matter summarizes many scientific observations about matter: It states that there is no detectable change in the total quantity of matter present when matter converts from one type to another (a chemical change) or changes among solid, liquid, or gaseous states (a physical change). Brewing beer and the operation of batteries provide examples of the conservation of matter (Figure 1.8). During the brewing of beer, the ingredients (water, yeast, grains, malt, hops, and sugar) are... Q: Some samples of matter appear to have properties of solids, liquids, and/or gases at the same time. this can occur when the sample is composed of many what? Choices: - turn pieces - large pieces - few pieces - small pieces A:
(Answer)
small pieces
Ques: Answer the following question given this paragraph: Figure 31.3 Cellulose, the main structural component of the plant cell wall, makes up over thirty percent of plant matter. It is the most abundant organic compound on earth. Plants are able to make their own cellulose, but need carbon from the soil to do so. Q: Cellulose is the main structural component of what part of the plant cell, and makes up over thirty percent of plant matter? Choices: - flowers - roots - proteins wall - cell wall A:
Ans: cell wall
(Q).
Answer the following question given this paragraph: Since the mid 1800s, Earth has warmed up quickly. Look at Figure below . The 14 hottest years on record have all occurred since 1900. Eight of them have occurred since 1998! This is what is usually meant by global warming . Q: Eight of the hottest years on record have occurred since what year? Choices: - 2002 - 1997 - 1991 - 1998 A:
(A).
1998
Ques:Answer the following question given this paragraph: In the Cell Cycle: Cancer (Advanced) concept, cancer is described as developing due to unregulated cell division. That is, cancer is a disease characterized by a population of cells that grow and divide without respect to normal limits. These cancerous cells invade and destroy adjacent tissues, and they may spread throughout the body. The process by which normal cells are transformed into cancer cells is known as carcinogenesis . This process is also known as oncogenesis or tumorigenesis. Oncogenes are mutated genes involved in the development of cancer. Q: Cancer develops when what process is unregulated? Choices: - metabolism - meiosis - cellular respiration - cell division A:

Ans:cell division
Answer the following question given this paragraph: The process in which rocks or other solids change to liquids is called melting. Melting occurs when particles of a solid absorb enough energy to partly overcome the force of attraction holding them together. This allows them to move out of their fixed positions and slip over one another. Melting, like other changes of state, is a physical change in matter, so it doesn't change the chemical makeup or chemical properties of matter. Q: At what temperature does solid water melt to a liquid? Choices: - below 32 degrees c - below 0 degrees c - above 32 degrees c - at temperatures above 0 degrees c A:
at temperatures above 0 degrees c