bioligy

A student adds a suspension of baker's yeast cells into bread dough. After this mixture is left in a large bowl undisturbed for several hours, the student returns to find that the bread dough has doubled in size. Which gas molecule is responsible for this increase in dough size?

CO2

A scientist is studying the metabolic processes carried out by a certain bacterium. Which of the following observations would indicate that the bacterium is performing fermentation?

Ethyl alcohol is produced.

Which of the following statements about aerobic respiration is correct?

It requires oxygen.

Which of the following can be a product of fermentation?

lactic acid

The chemical reaction for photosynthesis is: 6CO2 + 6H2O → C6H12O6 + 6O2 The chemical reaction for cellular respiration is: C6H12O6 + 6O2 → 6CO2 + 6H2O What can be said about these two reactions?

The products of photosynthesis are the reactants of cellular respiration.

Yeast contained in bread dough perform fermentation, which causes the bread to rise. Which gas released by the yeast causes the bread to rise?

carbon dioxide

In the respiration-photosynthesis cycle shown above, what are the reactants of photosynthesis that belong in box 2?

carbon dioxide and water

Plant and animal cells release energy stored in the bonds of glucose molecules when they perform

cellular respiration.

During cellular respiration, the bonds of food molecules are broken, so energy can be released to fuel other cellular processes. In order for this to occur, which of the following statements must be true?

New compounds with lower-energy bonds must be formed when the high-energy bonds in food molecules are broken.

Which of the following is true about plants and cellular energy?

Plants use light energy to produce food molecules during photosynthesis and obtain cellular energy from the bonds of these food molecules during cellular respiration.

Which biological process involves the conversion of one type of chemical energy into another type of chemical energy?

cellular respiration

Which of the following are products in the process of photosynthesis?

glucose and oxygen

During the process of photosynthesis, chlorophyll within the leaves of plants captures light energy from the Sun to produce simple sugars. What gas is released into the air as a byproduct of photosynthesis?

oxygen

During _______, energy from the Sun is stored in the bonds of sugar molecules.

photosynthesis

The food an animal eats provides the energy needed for that animal's life processes. The following diagram shows an example of how energy can flow through the environment to a human's cells. Which energy source would most appropriately fill the first box?

Solar energy is the initial source of energy for most ecosystems.

Amino acids contain the elements carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur. Of the 20 amino acids found in humans, 11 are called "nonessential" because they can be manufactured by the body when needed. Which elements in these 11 amino acids are commonly obtained from the metabolism of sugar molecules?

hydrogen carbon oxygen

A student isolates an unknown bacterial sample from the bottom of a swamp area. The student discovers that this species of bacteria is able to live and grow in an oxygen-free environment, but it requires a nitrate-rich soil. Which of the following respiration pathways is this species of bacteria most likely using?

anaerobic respiration

During photosynthesis, plants capture light energy from the Sun to break the bonds in reactants, such as carbon dioxide and water, and form carbon-containing molecules, such as glucose. The carbon-containing molecules can then be used

to assemble larger molecules, such as DNA, proteins, and fats.

Organisms undergo many different processes in order to be able to store energy and utilize that energy. Through which of the following processes is energy released in the form of ATP?

cellular respiration

During the process of photosynthesis, plants use energy from the Sun to convert carbon dioxide and water into glucose and oxygen. These products are, in turn, used by the plant or animals that eat the plant during cellular respiration to produce ATP. ATP molecules store cellular energy. When phosphate groups are removed and molecules of ADP are formed, energy is released. This energy can be used to perform

cellular work.

Which of the following are reactants in the process of aerobic respiration?

glucose and oxygen

During cellular respiration, energy is stored in the form of _______.

ATP

In the deepest parts of Earth's oceans, there are no photosynthetic organisms to produce molecular oxygen. As a result, these areas are called "anaerobic" environments. Which organism would most likely be able to survive in an anaerobic environment like the one described?

a bacterium that uses sulfate during respiration

Which of the following are products in the process of aerobic respiration?

carbon dioxide and water

Which of the following are reactants in the process of photosynthesis?

carbon dioxide and water

At the beginning of cellular respiration, energy is stored in the bonds of molecules. At the end of cellular respiration, energy is stored in the bonds of molecules.

glucose ATP

In the respiration-photosynthesis cycle shown above, what are the products of photosynthesis that belong in box 1?

glucose and oxygen

During photosynthesis, plants take in light energy from the Sun, carbon dioxide from the air, and water through their roots. Which of the following is a product of photosynthesis?

glucose sugar oxygen

During photosynthesis, radiant energy from the Sun is transferred to plants and other photosynthetic organisms. The chloroplasts in the cells of these organisms then transform the radiant energy into chemical potential energy stored in the bonds of

highly condensed carbon compounds such as carbohydrates.

Which of these is the main difference between aerobic respiration and anaerobic respiration?

Anaerobic respiration does not require oxygen.

A researcher performed an experiment in which he exposed young corn plants to a harmless, radioactive form of carbon dioxide gas containing carbon-14 instead of carbon-12. He then began feeding corn produced by the plants to a small group of goats. After several weeks, the researcher took blood and tissue samples from the goats. He was able to detect increased concentrations of carbon-14 in the goats' lipids, proteins, carbohydrates, and DNA. Which statement best explains the researcher's findings?

Carbon atoms found in the sugar molecules of the corn were used by the goats' bodies to form other large molecules.

During photosynthesis, plant cells take in water (H2O) and carbon dioxide (CO2) and release oxygen (O2). How is this different from what takes place during aerobic respiration?

During aerobic respiration, cells take in O2 and release CO2, H2O, and ATP.

What type of energy transformation takes place during photosynthesis?

Light energy is converted into chemical energy.

A falcultative anaerobic organism is able to perform aerobic respiration in the presence of oxygen and fermentation in the absence of oxygen. An example of a falcultative anaerobic organism is brewer's yeast, which is used in the production of alcoholic beverages. If sealed in a vessel containing oxygen gas, water, and sugar (glucose), the yeast will eventually deplete the oxygen gas. As long as glucose is available, however, the yeast can still survive. Brewer's yeast use oxygen preferentially because

aerobic respiration is more efficient than fermentation.

Organisms undergo many different processes in order to be able to store energy and utilize that energy. Through which of the following processes is energy stored in the form of glucose?

photosynthesis

Which process provides a vital connection between the Sun and the energy needs of living systems?

photosynthesis