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Large viruses began as what type of cells inside bigger host cells?

parasitic

Large viruses were once parasitic cells inside bigger host cells. Over time, genes needed to survive and reproduce outside host cells were lost.

Frogs and toads have long back legs which are specialized for what action?

jumping

Frogs The frog order also includes toads. Unlike other amphibians, frogs and toads lack a tail by adulthood. Their back legs are also longer because they are specialized for jumping. Frogs can jump as far as 20 times their body length. That’s like you jumping more than the length of a basketball court! red-eyed tree frog.

What is the term for a change in the inherited traits of organisms over time?

evolution

Darwin proposed the theory of evolution by natural selection. Evolution is a change in the inherited traits of organisms over time. Natural selection is the process by which living things with beneficial traits produce more offspring, so their traits become more common over time.

What type of diseases do antibiotics not affect?

viruses

Viruses are not affected by antibiotics. Several viral diseases can be treated with antiviral drugs or prevented with vaccines.

How do reptiles typically reproduce?

sexually

Reptiles typically reproduce sexually and lay eggs.

All organisms must adapt to what in order to survive?

environment

All organisms must adapt to their environment in order to survive. This is true whether they live in water or on land. Most environments are not as extreme as the deep ocean where tube worms live. But they all have conditions that require adaptations. In this chapter, you will read about a wide variety of environments and the organisms that live in them.

Biochemical compounds that include sugars, starches, and cellulose are examples of what?

carbohydrates

Carbohydrates are biochemical compounds that include sugars, starches, and cellulose. They contain carbon, hydrogen, and oxygen, and they are used mainly for energy by living things.

What emerges from an insect egg?

larva

When an insect egg hatches, a larva emerges. The larva eats and grows and then enters the pupa stage. The pupa is immobile and may be encased in a cocoon . During the pupa stage, the insect goes through metamorphosis . Tissues and appendages of the larva break down and reorganize into the adult form. How did such an incredible transformation evolve? Metamorphosis is actually very advantageous. It allows functions to be divided between life stages. Each stage can evolve adaptations to suit it for its specific functions without affecting the adaptations of the other stage.

What can protons and neutrons be broken down into?

quarks

Today, scientists think that electrons truly are fundamental particles that cannot be broken down into smaller, simpler particles. They are a type of fundamental particles called leptons. Protons and neutrons, on the other hand, are no longer thought to be fundamental particles. Instead, they are now thought to consist of smaller, simpler particles of matter called quarks. Scientists theorize that leptons and quarks are held together by yet another type of fundamental particles called bosons. All three types of fundamental particles—leptons, quarks, and bosons—are described below. The following Figure below shows the variety of particles of each type.

What is the name of the stage of life when a child becomes sexually mature?

puberty

Puberty is the stage of life when a child becomes sexually mature. Puberty lasts from about 10 to 16 years of age in girls and from about 12 to 18 years of age in boys. In both girls and boys, puberty begins when the pituitary gland signals the gonads (ovaries or testes) to start secreting sex hormones (estrogen in girls, testosterone in boys). Sex hormones, in turn, cause many other changes to take place.

What part of the brain is divided from front to back into the left and right hemispheres?

cerebrum

The cerebrum is divided down the middle from the front to the back of the head. The two halves of the cerebrum are called the right and left hemispheres. The two hemispheres are very similar but not identical. They are connected to each other by a thick bundle of axons deep within the brain. These axons allow the two hemispheres to communicate with each other. Did you know that the right hemisphere of the cerebrum controls the left side of the body, and vice versa? This can happen because of the connections between the two hemispheres.

Because their cells are arranged in bundles, the appearance of skeletal and cardiac muscles is described as what?

striated

http://zonalandeducation. com/mstm/physics/mechanics/vectors/introduction/introductionVectors. html.

What resource is considered nonrewable for human purposes, because it takes so long to form and is depleted by farming and other activities?

soil

Although renewable, soil takes a very long to form—up to hundreds of millions of years. So, for human purposes, soil is a nonrenewable resource. It is also constantly depleted of nutrients through careless use and eroded by wind and water. For example, misuse of soil caused a huge amount of it to simply blow away in the 1930s during the Dust Bowl (see Figure below ). Soil must be used wisely to preserve it for the future. Conservation practices include contour plowing and terracing. Both reduce soil erosion. Soil also must be protected from toxic wastes.

What scientist created the modern system for classifying organisms?

linnaeus

Linnaeus published his classification system in the 1700s. Since then, many new species have been discovered. The biochemistry of many organisms has also become known. Eventually, scientists realized that Linnaeus’s system of classification needed revision.

Since warmer molecules have more energy, they are more what?

active

The density of air varies from place to place. Air density depends on several factors. One is temperature. Like other materials, warm air is less dense than cool air. Since warmer molecules have more energy, they are more active. The molecules bounce off each other and spread apart. Another factor that affects the density of air is altitude.

Which type of animal creates useful substances such as honey, wax, lacquer, and silk?

insects

Insects produce useful substances, such as honey, wax, lacquer, and silk.

Stringed instruments can help show the relationship between tension and what in strings?

frequencies

f 2 = v w / λ 2 = v w / 2L = 2 f 1 . Similarly, f 3 = 3 f 1 , and so on. All of these frequencies can be changed by adjusting the tension in the string. The greater the tension, the greater v w is and the higher the frequencies. This observation is familiar to anyone who has ever observed a string instrument being tuned. We will see in later chapters that standing waves are crucial to many resonance phenomena, such as in sounding boxes on string instruments.

Ectotherms undergo a variety of changes at the cellular level to acclimatize to shifts in what?

temperature

There are 44 autosomes and 2 sex chromosomes in the human genome, for a total of 46 chromosomes (23 pairs). Sex chromosomes specify an organism's genetic sex. Humans can have two different sex chromosomes, one called X and the other Y. Normal females possess two X chromosomes and normal males one X and one Y. An autosome is any chromosome other than a sex chromosome. The Figure below shows a representation of the 24 different human chromosomes. Figure below shows a karyotype of the human genome. A karyotype depicts, usually in a photograph, the chromosomal complement of an individual, including the number of chromosomes and any large chromosomal abnormalities. Karyotypes use chromosomes from the metaphase stage of mitosis.

Convex lenses are thicker in the middle than at the edges so they cause rays of light to converge, or meet, at a point called what?

focus

Convex lenses are thicker in the middle than at the edges. They cause rays of light to converge, or meet, at a point called the focus (F). Convex lenses form either real or virtual images. It depends on how close an object is to the lens relative to the focus. Figure below shows how a convex lens works. You can also interact with an animated convex lens at the URL below. An example of a convex lens is a hand lens.

What are magnesium carbonate, aluminum hydroxide, and sodium bicarbonate commonly used as?

antacids

Magnesium carbonate, aluminum hydroxide, and sodium bicarbonate are commonly used as antacids. Give the empirical formulas and determine the molar masses of these compounds. Based on their formulas, suggest another compound that might be an effective antacid. ♦ Nickel(II) acetate, lead(II) phosphate, zinc nitrate, and beryllium oxide have all been reported to induce cancers in experimental animals.

What type of taste do bases normally have?

bitter

Bases often have a bitter taste and are found in foods less frequently than acids. Many bases, like soaps, are slippery to the touch.

The maintenance of constant conditions in the body is also known as what?

homeostasis

Homeostasis, or the maintenance of constant conditions in the body, is a fundamental property of all living things. In the human body, the substances that participate in chemical reactions must remain within narrows ranges of concentration. Too much or too little of a single substance can disrupt your bodily functions. Because metabolism relies on reactions that are all interconnected, any disruption might affect multiple organs or even organ systems. Water is the most ubiquitous substance in the chemical reactions of life. The interactions of various aqueous solutions—solutions in which water is the solvent—are continuously monitored and adjusted by a large suite of interconnected feedback systems in your body. Understanding the ways in which the body maintains these critical balances is key to understanding good health.

What is the term for tough protein fibers that connects bones to each other?

ligaments

Ligaments are made of tough protein fibers and connect bones to each other. Your bones, cartilage, and ligaments make up your skeletal system .

What is the first part of the large intestine called?

cecum

Cecum The first part of the large intestine is the cecum, a sac-like structure that is suspended inferior to the ileocecal valve. It is about 6 cm (2.4 in) long, receives the contents of the ileum, and continues the absorption of water and salts. The appendix (or vermiform appendix) is a winding tube that attaches to the cecum. Although the 7.6-cm (3-in) long appendix contains lymphoid tissue, suggesting an immunologic function, this organ is generally considered vestigial. However, at least one recent report postulates a survival advantage conferred by the appendix: In diarrheal illness, the appendix may serve as a bacterial reservoir to repopulate the enteric bacteria for those surviving the initial phases of the illness. Moreover, its twisted anatomy provides a haven for the accumulation and multiplication of enteric bacteria. The mesoappendix, the mesentery of the appendix, tethers it to the mesentery of the ileum.

Boyle discovered that what property of a gas is inversely proportional to its volume?

pressure

in a one-liter container (Figure 22.15). In this case, the force exerted by the movement of the gas molecules against the walls of the two-liter container is lower than the force exerted by the gas molecules in the one-liter container. Therefore, the pressure is lower in the two-liter container and higher in the one-liter container. At a constant temperature, changing the volume occupied by the gas changes the pressure, as does changing the number of gas molecules. Boyle’s law describes the relationship between volume and pressure in a gas at a constant temperature. Boyle discovered that the pressure of a gas is inversely proportional to its volume: If volume increases, pressure decreases. Likewise, if volume decreases, pressure increases. Pressure and volume are inversely related (P = k/V). Therefore, the pressure in the one-liter container (one-half the volume of the two-liter container) would be twice the pressure in the two-liter container. Boyle’s law is expressed by the following formula:.

What is the layer of tissue between the body and shell called?

mantle

Mollusks have a hard outer shell. There is a layer of tissue called the mantle between the shell and the body.

Well suited to absorb water and dissolved minerals from the soil, thin-walled dermal cells and tiny hairs cover what basic plant structures?

roots

Roots are covered with thin-walled dermal cells and tiny root hairs. These features are well suited to absorb water and dissolved minerals from the soil.

What is the major artery of the body, taking oxygenated blood to the organs and muscles of the body?

aorta

The Heart The heart is a complex muscle that consists of two pumps: one that pumps blood through pulmonary circulation to the lungs, and the other that pumps blood through systemic circulation to the rest of the body’s tissues (and the heart itself). The heart is asymmetrical, with the left side being larger than the right side, correlating with the different sizes of the pulmonary and systemic circuits (Figure 16.10). In humans, the heart is about the size of a clenched fist; it is divided into four chambers: two atria and two ventricles. There is one atrium and one ventricle on the right side and one atrium and one ventricle on the left side. The right atrium receives deoxygenated blood from the systemic circulation through the major veins: the superior vena cava, which drains blood from the head and from the veins that come from the arms, as well as the inferior vena cava, which drains blood from the veins that come from the lower organs and the legs. This deoxygenated blood then passes to the right ventricle through the tricuspid valve, which prevents the backflow of blood. After it is filled, the right ventricle contracts, pumping the blood to the lungs for reoxygenation. The left atrium receives the oxygen-rich blood from the lungs. This blood passes through the bicuspid valve to the left ventricle where the blood is pumped into the aorta. The aorta is the major artery of the body, taking oxygenated blood to the organs and muscles of the body. This pattern of pumping is referred to as double circulation and is found in all mammals. (Figure 16.10).

What do you call a growing mass of cancerous cells that pushes into nearby tissues?

tumor

Lung cancer is a disease in which the cells found in the lungs grow out of control. The growing mass of cells can form a tumor that pushes into nearby tissues. The tumor will affect how these tissues work. Lung cancer is the most common cause of cancer-related death in men, and the second most common in women. It is responsible for 1.3 million deaths worldwide every year ( Figure below ). The most common symptoms are shortness of breath, coughing (including coughing up blood), and weight loss. The most common cause of lung cancer is exposure to tobacco smoke.

What is the major intracellular cation?

potassium

Potassium Potassium is the major intracellular cation. It helps establish the resting membrane potential in neurons and muscle fibers after membrane depolarization and action potentials. In contrast to sodium, potassium has very little effect on osmotic.

The enzyme pepsin plays an important role in the digestion of proteins by breaking down intact protein to what short-chain amino acids?

peptides

Protein A large part of protein digestion takes place in the stomach. The enzyme pepsin plays an important role in the digestion of proteins by breaking down the intact protein to peptides, which are short chains of four to nine amino acids. In the duodenum, other enzymes— trypsin, elastase, and chymotrypsin—act on the peptides reducing them to smaller peptides. Trypsin elastase, carboxypeptidase, and chymotrypsin are produced by the pancreas and released into the duodenum where they act on the chyme. Further breakdown of peptides to single amino acids is aided by enzymes called peptidases (those that break down peptides). Specifically, carboxypeptidase, dipeptidase, and aminopeptidase play important roles in reducing the peptides to free amino acids. The amino acids are absorbed into the bloodstream through the small intestines. The steps in protein digestion are summarized in Figure 34.17 and Table 34.6.

Terrestrial ecosystems, also known for their diversity, are grouped into large categories called what?

biomes

Terrestrial ecosystems, also known for their diversity, are grouped into large categories called biomes. A biome is a largescale community of organisms, primarily defined on land by the dominant plant types that exist in geographic regions of the planet with similar climatic conditions. Examples of biomes include tropical rainforests, savannas, deserts, grasslands, temperate forests, and tundras. Grouping these ecosystems into just a few biome categories obscures the great diversity of the individual ecosystems within them. For example, the saguaro cacti (Carnegiea gigantean) and other plant life in the Sonoran Desert, in the United States, are relatively diverse compared with the desolate rocky desert of Boa Vista, an island off the coast of Western Africa (Figure 20.3).

High explosives create shock waves that exceed the speed of sound, a phenomenon that goes by what term?

supersonic

The modern day formulation of gun powder is called black powder. It is still commonly used today. Its formulation is still quite similar to what was used in 9 th century China. Black powder is considered a low explosive. It is a mixture that burns quickly, but the resulting shock wave travels at subsonic speeds. The speed at which it burns is dependent on the accessibility of oxygen atoms to the carbon source. In contrast, high explosives like nitroglycerin detonate instead of burning, creating shock waves that are supersonic (faster than the speed of sound).

What do you call a structure composed of two or more types of tissues that work together to do a specific task?

organ

An organ is a structure composed of two or more types of tissues that work together to do a specific task. Most modern plants have several organs that help them survive and reproduce in a variety of habitats. Major organs of most plants include roots, stems, and leaves. These and other plant organs generally contain all three major tissue types.