Answer the following question given this paragraph: The first organisms were made of only one cell ( Figure below ). The earliest cells were prokaryotes . Prokaryotic cells are surrounded by a cell membrane. They do not have a nucleus. Their organelles are free in the cell. The cells get their nutrients directly from the water they live in. The cells need to use these nutrients to live and grow. Q: The earliest cells were prokaryotes, surrounded by a cell membrane but lacking which key structure? Choices: - mitochondria - ribosomes - lysosomes - nucleus A:
nucleus
(Question)
Answer the following question given this paragraph: Steps of Virus Infections A virus must use cell processes to replicate. The viral replication cycle can produce dramatic biochemical and structural changes in the host cell, which may cause cell damage. These changes, called cytopathic (causing cell damage) effects, can change cell functions or even destroy the cell. Some infected cells, such as those infected by the common cold virus known as rhinovirus, die through lysis (bursting) or apoptosis (programmed cell death or "cell suicide"), releasing all progeny virions at once. The symptoms of viral diseases result from the immune response to the virus, which attempts to control and eliminate the virus from the body, and from cell damage caused by the virus. Many animal viruses, such as HIV (human immunodeficiency virus), leave the infected cells of the immune system by a process known as budding, where virions leave the cell individually. During the budding process, the cell does not undergo lysis and is not immediately killed. However, the damage to the cells that the virus infects may make it impossible for the cells to function normally, even though the cells remain alive for a period of time. Most productive viral infections follow similar steps in the virus replication cycle: attachment, penetration, uncoating, replication, assembly, and release (Figure 21.8). Attachment A virus attaches to a specific receptor site on the host cell membrane through attachment proteins in the capsid or via glycoproteins embedded in the viral envelope. The specificity of this interaction determines the hostand the cells within the hostthat can be infected by a particular virus. This can be illustrated by thinking of several keys and several locks, where each key will fit only one specific lock. Q: Symptoms of viral diseases result from what kind of response to a virus? Choices: - infection - pathogenic - mutation - immune A:
(Answer)
immune
Ques: Answer the following question given this paragraph: Nearly all fish reproduce sexually and have separate sexes. Fertilization is generally external, and most fish are oviparous. Many adults of the same species may come together in a group and release gametes into the water at the same time, which is called spawning. Fish hatch into larvae that are different from the adult form of the species. Q: What do you call it when adult fish of the same species come together in a group and release gametes into the water at the same time? Choices: - migration - schoaling - poaching - spawning A:
Ans: spawning
(Q).
Answer the following question given this paragraph: The Table below compares the specific heat of four different substances. Metals such as iron have low specific heat. It doesn't take much energy to raise their temperature. That's why a metal spoon heats up quickly when placed in a cup of hot coffee. Sand also has a relatively low specific heat. Water, on the other hand, has a very high specific heat. It takes a lot more energy to increase the temperature of water than sand. This explains why the sand on a beach gets hot while the water stays cool. Differences in the specific heat of water and land even affect climate. To learn how, watch the video at this URL: http://www. youtube. com/watch?v=dkBStF2Rnu4. Q: Why does a metal spoon heat up quickly when placed in a hot drink? Choices: - insulation - high specific heat - convection - low specific heat A:
(A).
low specific heat
Ques:Answer the following question given this paragraph: The most important way that humans communicate is with language. Language is the use of symbols to communicate. In human languages, the symbols are words. Words may stand for things, people, actions, feelings, or ideas. By combining words in sentences, language can be used to express very complex thoughts. Q: What is the most important way that humans communicate? Choices: - inheritance - painting - instinct - language A:

Ans:language
Answer the following question given this paragraph: Zinc reacting with hydrochloric acid produces bubbles of hydrogen gas. Q: Zinc reacting with hydrochloric acid produces bubbles of which gas? Choices: - carbon - helium - mustard - hydrogen A:
hydrogen