Resumen de alcance por ámbito, lo que incluye y lo que no se incluye.

D) It is a process that doesn’t take place in green plants when photosynthesis is taking place.

Appendix C Instructional Explanations Question 1

Plants don’t ‘get food’ from anywhere. Plants make their own food through photosynthesis. During photosynthesis, carbon dioxide and water react together in the presence of light energy and chlorophyll to make glucose. The glucose is converted into starch, fats and oils for storage. This food provides energy for them to carry out cellular processes.

Question 2

Plants use carbon dioxide in photosynthesis, which in turn produces oxygen as a byproduct. The oxygen produced during photosynthesis is used in cellular respiration. Almost all living things, including plants, get energy from cellular respiration. Cellular respiration then produces carbon dioxide as a byproduct. This carbon dioxide moves into the leaves of plants and the cycle continues.

Question 3

Explanation: Photosynthesis only takes place where there is chlorophyll (only found in green plants) and light energy. However, respiration is taking place in plants at all times, because it does not require light energy. The plant can store the sugars made in photosynthesis and continue to synthesize them through respiration at night. Respiration and photosynthesis can take place simultaneously in plants, even within the same cells. Continuous cellular respiration is necessary to keep cells alive, so it is occurring in plants and animals at all times.

Question 4

The metabolic energy produced by cellular respiration allows cells to carry out the basic functions needed to stay alive. Cellular respiration combines oxygen and the glucose created during photosynthesis to produce this usable energy (ATP). While cells can cooperate to get oxygen and glucose to other cells, but they cannot donate ATP to other cells; each cell must make its own ATP through respiration. If a cell doesn’t make its own ATP, it won’t be able to carry out cellular processes, eventually causing it to die.

Question 5

Green plants will photosynthesize in the presence of sunlight. During photosynthesis, the energy from the sun splits water molecules into hydrogen and oxygen. While some of the Oxygen molecules are then used to synthesize ATP, most are released back into the air.

Question 6

Only respiration, not photosynthesis, continues to take place in plants in the absence of light energy. In fact, respiration is taking place all the time. This includes both during photosynthesis and in the absence of photosynthesis. Oxygen is required for respiration, so plants will continue to take in large amounts of oxygen at night in order to respire. Thus, oxygen is taken by green plants in large amounts when there is no light energy.

Question 7

mass that makes up those sugar molecules comes from the carbon and oxygen atoms originally contained in atmospheric carbon dioxide. The added mass comes from the CO2 molecules taken in by the plants leaves. Some minerals from the soil can account for a very small amount of biomass increase, but most of the mass comes from the carbon in CO2.

Question 8

CO2 and H20 are both waste products of respiration. The seeds in the “No light, Water” treatment would have been respiring throughout the experiment, because respiration does not require light. Since the seeds could not photosynthesize without light, the only byproducts released would have been from respiration.

Question 9

The plant will weigh less, because it will continue to go through cellular respiration in the dark. During cellular respiration CO2, which has mass, is given off. Since the plant cannot

photosynthesize in the dark and gain mass, it will continue to lose mass through respiration in the absence of light energy.

Question 10

Roots cannot photosynthesize, because they are not exposed to light energy and do not (typically) contain chlorophyll. Since roots can't produce sugars through photosynthesis, they must get sugars from plant cells that do photosynthesize. The plant can coordinate to transport sugars to root cells, but the plant cannot transport ATP cells. Thus, root cells will receive sugars from photosynthetic cells and create ATP through their own respiration.

Question 11

Chloroplasts are the energy factories that produce sugars through photosynthesis. These sugars are used by respiration to make ATP. This ATP provides the usable energy required for the cellular processes that are necessary for cells to stay alive. However, the chloroplasts do not produce the ATP themselves, rather they produce the sugar needed for respiration to make ATP. Question 12

Respiration consists of a complicated series of chemical reactions that turn the sugars made into ATP. In the first stage, glucose is oxidized, and the chemical potential energy of its bonds is transferred to the chemical potential bonds of an ATP molecule. The ATP molecule can then be transported throughout the cell where its stored energy is used to complete various tasks within the cell. This process is taking place all the time and provides the metabolic energy required by all cells to function and stay alive.

Appendix D Posttest Questions Correct answers are in bold 1) Where does the food that a plant needs come from?

A) The plant makes its food from minerals and water.

B) The food comes in from the soil through the plant’s roots. C) The food comes in from the air through the plant’s leaves. D) The food comes in both from the soil and the air.