1.
Why do plants undergo photosynthesis?
Correct Answer
B. To produce organic compounds that the plants can then use in respiration
Explanation
Plants undergo photosynthesis to produce organic compounds that they can use in respiration. During photosynthesis, plants convert sunlight, water, and carbon dioxide into glucose and oxygen. The glucose is then used by the plant for energy through respiration. This process allows plants to create their own food and provide the necessary energy for their growth, development, and other essential functions.
2.
Which organelle(s) is/are important for energy in plant cells?
Correct Answer
C. Both a and b
Explanation
Both mitochondria and chloroplasts are important for energy in plant cells. Mitochondria are known as the powerhouses of the cell, where cellular respiration takes place, producing ATP (adenosine triphosphate) which is the energy currency of the cell. Chloroplasts, on the other hand, are responsible for photosynthesis, the process by which plants convert sunlight into chemical energy in the form of glucose. Therefore, both organelles play crucial roles in generating energy for plant cells.
3.
Metabolism is defined as:
Correct Answer
B. The sum of all chemical processes that occur in an organism
Explanation
Metabolism refers to the sum of all chemical processes that take place within an organism. It includes processes such as digestion, respiration, and the conversion of food into energy. Metabolism is not solely focused on the rate at which energy is burned or the burning of fat, but encompasses a wide range of biochemical reactions that occur in an organism to maintain life and support its various functions.
4.
Where does all the energy for everything come from?
Correct Answer
A. The sun
Explanation
The sun is the ultimate source of energy for everything on Earth. Through the process of nuclear fusion, the sun releases vast amounts of energy in the form of light and heat. This energy is then captured by plants through photosynthesis, converting it into chemical energy. Animals obtain this energy by consuming plants or other animals. Thus, the sun provides the energy necessary for all life processes and activities on Earth.
5.
Which comes first: Photosystem I (PSI) or Photosystem II (PSII)?
Correct Answer
B. PSII
Explanation
Photosystem II (PSII) comes before Photosystem I (PSI) in the process of photosynthesis. PSII is responsible for capturing light energy and using it to split water molecules, releasing oxygen and generating ATP (adenosine triphosphate) in the process. The electrons from PSII are then passed on to PSI, where they are re-energized and used to produce NADPH (nicotinamide adenine dinucleotide phosphate), another energy-rich molecule. Therefore, PSII must come first in order to provide the necessary energy and components for PSI to function.
6.
Where do chloroplasts live?
Correct Answer
A. Mesophyll cells
Explanation
Chloroplasts live in mesophyll cells. Mesophyll cells are specialized cells found in the leaves of plants that contain chloroplasts. These chloroplasts are responsible for carrying out photosynthesis, the process by which plants convert sunlight into energy. Therefore, the correct answer is mesophyll cells as they provide the location for chloroplasts to carry out their function.
7.
The stroma of a thylakoid can be compared to the ___________ of a plant cell (or even animal cell)
Correct Answer
cytoplasm
Explanation
The stroma of a thylakoid can be compared to the cytoplasm of a plant or animal cell. Just like the cytoplasm, the stroma is a gel-like substance that fills the thylakoid membrane. It contains various enzymes, molecules, and ions that are necessary for the biochemical reactions that occur during photosynthesis. Similarly, the cytoplasm of a cell is a fluid-filled region that contains various organelles, enzymes, and molecules required for cellular processes. Therefore, the stroma can be compared to the cytoplasm in terms of their composition and function within the cell.
8.
One stack of thylakoids is called a ________.
Correct Answer
granum
Explanation
A stack of thylakoids is called a granum. Thylakoids are membrane-bound compartments found in chloroplasts, which are responsible for carrying out photosynthesis in plants. These thylakoids are arranged in stacks called grana, with each stack containing multiple thylakoids. The grana play a crucial role in the light-dependent reactions of photosynthesis by providing a large surface area for the absorption of light and the production of ATP and NADPH. Therefore, the correct answer is granum.
9.
Plants, algae, and some bacteria capture about ____% of the energy in the sunlight that reaches Earth.
Correct Answer
1
one
10.
Photosynthesis is the process that provides energy for all life.
Correct Answer
B. False
Explanation
Photosynthesis provides energy for ALMOST all life.
11.
Put these steps of photosynthesis in the correct order.
1. Light energy is converted to chemical energy. This chemical energy is temporarily stored in ATP and NADpH, an energy carrier molecule.
2. The chemical energy (stored in ATP and NADpH) powers the formation of organic compounds, using carbon dioxide.
3. Energy is captured from sunlight.
Correct Answer
B. 3, 1, 2
Explanation
The first step in photosynthesis is capturing energy from sunlight (3). This energy is then used to convert light energy into chemical energy, which is temporarily stored in ATP and NADPH (1). Finally, this stored chemical energy powers the formation of organic compounds using carbon dioxide (2). Therefore, the correct order is 3, 1, 2.
12.
Photosynthesis takes place in the _______ of plants.
Correct Answer
Chloroplasts, chloroplasts
Explanation
Chloroplasts are the organelles in plant cells where photosynthesis occurs. They contain chlorophyll, the green pigment that absorbs light energy, which is then used to convert carbon dioxide and water into glucose (a type of sugar) and oxygen.
13.
Some of the sugars that are created are used to make _____
Correct Answer
starch
starches
Explanation
Sugars are used to make starch and starches. Starch is a complex carbohydrate made up of many sugar molecules linked together. When plants produce sugars through photosynthesis, some of these sugars are used to synthesize starch. Starches are polysaccharides that serve as an energy storage molecule in plants. They are made up of multiple sugar units, which are created from the sugars produced by the plant. Therefore, both starch and starches are correct answers as they represent the end product of sugar utilization in plants.
14.
Starch is then stored in stems or roots of the plants and can be broken down to _____ whenever it is needed.
Correct Answer
A. ATP
Explanation
Starch is stored in stems or roots of plants as a long-term energy reserve. When energy is needed, starch can be broken down into glucose molecules. However, glucose is not the direct product of starch breakdown. Instead, starch is broken down into ATP (adenosine triphosphate), which is a molecule that stores and transports energy within cells. Therefore, ATP is the correct answer as it is the molecule that is produced when starch is broken down and used as a source of energy.
15.
What powers metabolism?
Correct Answer
C. ATP
Explanation
ATP (adenosine triphosphate) is the correct answer because it is the primary source of energy for cellular metabolism. It is produced during cellular respiration and fuels various metabolic processes in the body. Glucose is a source of energy, but it is converted into ATP through cellular respiration. Sunlight is necessary for photosynthesis, which produces glucose, but it does not directly power metabolism. Therefore, the correct answer is ATP.
16.
What can a wavelength be defined as?
Correct Answer
B. The distance between two consecutive waves
Explanation
A wavelength can be defined as the distance between two consecutive waves. It represents the length of one complete cycle of a wave, from one peak to the next or from one trough to the next. It is a fundamental property of waves and is commonly used to describe various types of waves, such as electromagnetic waves and sound waves.
17.
Light-absorbing substances are called _______________
Correct Answer
pigments
pigment
Explanation
Light-absorbing substances that are responsible for giving color to various objects are called pigments. Pigments can be found in nature or can be synthesized artificially. They are used in various applications such as coloring paints, inks, dyes, and cosmetics. Pigments absorb certain wavelengths of light and reflect or transmit others, resulting in the perception of color.
18.
Which chlorophyll is directly involved in the light reactions?
Correct Answer
A. Chlorophyll a
Explanation
Chlorophyll a is directly involved in the light reactions of photosynthesis. It is the primary pigment responsible for capturing light energy and converting it into chemical energy. Chlorophyll b, on the other hand, works in conjunction with chlorophyll a to broaden the range of light wavelengths that can be absorbed. However, chlorophyll a is the key pigment that initiates the light reactions by absorbing photons and transferring the energy to other molecules in the photosynthetic process.
19.
Chlorophyll b is known as an ___________ pigment.
Correct Answer
accessory
Explanation
Chlorophyll b is known as an accessory pigment because it assists chlorophyll a in capturing light energy during photosynthesis. While chlorophyll a is the primary pigment responsible for converting light energy into chemical energy, chlorophyll b helps to broaden the range of light wavelengths that can be absorbed. This allows plants to maximize their energy absorption from different light sources, such as blue and red light. Therefore, chlorophyll b plays a crucial role in enhancing the efficiency of photosynthesis by providing additional light-harvesting capabilities.
20.
The pigments that produce yellow and orange fall leaf colors and the colors of many fruits, vegetables, and flowers are called _____________.
Correct Answer
carotenoids
carotenoid
Explanation
Carotenoids are the pigments responsible for producing yellow and orange fall leaf colors, as well as the colors of many fruits, vegetables, and flowers. They are a class of plant pigments that give these organisms their vibrant hues. Carotenoids are also important for photosynthesis and act as antioxidants in plants.
21.
Pigments involved in photosynthesis are located in the __________ of leaf cells
Correct Answer
chloroplasts
chloroplast
Explanation
The pigments involved in photosynthesis are located in the chloroplasts of leaf cells. Chloroplasts are specialized organelles found in plant cells that contain chlorophyll, the main pigment responsible for capturing light energy during photosynthesis. These chloroplasts are responsible for converting light energy into chemical energy, which is then used to produce glucose and oxygen. Therefore, the correct answer is "chloroplasts."
22.
Clusters of pigments are in the membranes of disk-shaped structures called _________
Correct Answer
B. Thylakoids
Explanation
Clusters of pigments are found in the membranes of disk-shaped structures called thylakoids. These thylakoids are responsible for capturing light energy during photosynthesis. The pigments within the thylakoids absorb light and initiate the process of converting light energy into chemical energy, which is then used to produce ATP and NADPH for the synthesis of glucose. Thylakoids are an essential part of the chloroplasts in plant cells and play a crucial role in the light-dependent reactions of photosynthesis.
23.
Each cluster of pigments is known as a
Correct Answer
C. Photosystem
Explanation
A cluster of pigments in plants that are involved in the process of photosynthesis is called a photosystem. Photosystems are responsible for capturing light energy and converting it into chemical energy, which is used to produce glucose and oxygen. These pigments are located in the thylakoid membranes of chloroplasts and work together to absorb light of different wavelengths. By organizing pigments into photosystems, plants are able to efficiently capture and utilize light energy for the production of food.
24.
When do the light reactions begin?
Correct Answer
A. When accessory pigment molecules in both photosystems absorb light
Explanation
The light reactions in photosynthesis begin when accessory pigment molecules in both photosystems absorb light. These pigments, such as chlorophyll and carotenoids, are able to capture light energy and transfer it to the reaction centers of the photosystems. This absorption of light initiates a series of electron transfer reactions, leading to the production of ATP and NADPH, which are essential for the subsequent dark reactions of photosynthesis.
25.
When light strikes a thylakoid in a chloroplast, energy is transferred to _________ in a pair of __________ molecules. (separate answers with commas, example: tigers, bears)
Correct Answer
electrons, chlorophyll a
Explanation
When light strikes a thylakoid in a chloroplast, the energy is absorbed by chlorophyll molecules, specifically chlorophyll a. This energy is then transferred to electrons within the chlorophyll molecules, which become energized and enter an excited state. These energized electrons are then used in the process of photosynthesis to generate ATP and NADPH, which are essential for the production of glucose and other organic molecules.
26.
When a substance loses electrons, it undergoes a(n) _____________ reaction.
Correct Answer
oxidation
Explanation
When a substance loses electrons, it undergoes oxidation. Oxidation is a chemical reaction in which a substance loses electrons, resulting in an increase in its oxidation state. This process is often associated with the addition of oxygen or the removal of hydrogen from a substance. It is an important reaction in many chemical and biological processes, such as combustion and cellular respiration.
27.
Every oxidation reaction must be accompanied by a(n) _______________ reaction.
Correct Answer
reduction
Explanation
Every oxidation reaction involves the loss of electrons from a substance. In order to balance the loss of electrons, there must be a corresponding reduction reaction that involves the gain of electrons by another substance. This reduction reaction helps to maintain the overall charge balance in the reaction. Therefore, every oxidation reaction must be accompanied by a reduction reaction.
28.
Every oxidation reaction must be accompanied by a reduction reaction in which another substance accepts those electrons. This substance is called the __________ __________ ___________ and it is located in the thylakoid membrane.
Correct Answer
primary electron acceptor
Explanation
In oxidation reactions, electrons are lost from a substance. To maintain charge balance, these electrons must be accepted by another substance, which is called the primary electron acceptor. In the context of the thylakoid membrane, where photosynthesis takes place, the primary electron acceptor is responsible for accepting the electrons released during the oxidation of chlorophyll molecules. It plays a crucial role in the electron transport chain, transferring the electrons to downstream components, ultimately leading to the production of ATP and NADPH.
29.
The _______ ________ ________ lies between two large green clusters of pigment molecules. (hint: it's a step in photosynthesis AND cellular respiration)
Correct Answer
electron transport chain
Explanation
The electron transport chain is a step in both photosynthesis and cellular respiration. It is a series of proteins and molecules located in the inner mitochondrial membrane that transfers electrons and generates ATP. In photosynthesis, the electron transport chain is involved in the light-dependent reactions, where it transfers electrons from chlorophyll to generate energy. In cellular respiration, it is part of the final stage, where it accepts electrons from NADH and FADH2 and uses them to produce ATP. The electron transport chain is located between two large green clusters of pigment molecules, referring to chlorophyll in photosynthesis.
30.
The __________ ___________ ___________ is known as the series of molecules in the thylakoid membrane that accepts the electrons donated from the primary electron acceptor.
Correct Answer
electron transport chain
Explanation
The electron transport chain is a series of molecules in the thylakoid membrane that accepts the electrons donated from the primary electron acceptor. This process is crucial in photosynthesis as it helps generate ATP and NADPH, which are necessary for the production of glucose. The electrons are passed along the chain, creating a flow of energy that is used to power the synthesis of ATP molecules. Without the electron transport chain, the production of ATP and NADPH would be compromised, hindering the overall process of photosynthesis.
31.
The electron transport chain lies between two large green clusters of pigment molecules. A protein acts as a __________ _____.
Correct Answer
membrane pump
Explanation
The electron transport chain is located between two large green clusters of pigment molecules. In this process, a protein acts as a membrane pump. This means that it helps transport electrons across the membrane, creating a flow of charged particles that generates energy. The protein acts as a pump by utilizing the energy from the electron transfer to move protons across the membrane, creating a concentration gradient that can be used to generate ATP.
32.
The energy lost by the electrons as they pass through each protein is used for what?
Correct Answer
D. Both a and b
Explanation
The energy lost by electrons as they pass through each protein in the electron transport chain is used to power both the electron transport chain itself (option a) and ATP synthase (option b). The electron transport chain generates a proton gradient across a membrane (in mitochondria or chloroplasts), and ATP synthase utilizes the energy from this gradient to synthesize ATP, which is the main energy currency of the cell. Therefore, both processes are crucial for cellular energy production.