Biology Midterm Exam Review 2021
Morgan has diabetes and must carefully monitor his food intake. He is learning the calorie count of the different macromolecules—carbohydrates, proteins, and fats—so that he can make choices to keep his blood sugar in the proper range. He notices that the word calorie is sometimes spelled with a capital C. Which statements accurately describe calories and Calories? Select all of the answers that apply.
A Calorie is equal to 1000 calories, A Calorie is equal to a kilocalorie.
Cells with DNA damage undergo apoptosis.
Cancer cell
They are non-differentiated cells.
Cancer cell
This process increases number of body cells
Cell Division
This process produces specialized cells.
Cell Division
This process repairs injuries
Cell Division
All cells contain cell membranes. Which of the following describes the composition of cell membranes?
Cell membranes are composed of lipid molecules, which provide a flexible structure.
The molecules in the food we eat contain chemical energy stored in chemical bonds. Which statement BEST explains how this energy is released?
Chemical bonds in food molecules are broken, releasing energy and allowing cells to use the energy to make ATP.
ATP, a higher-energy molecule than ADP, is synthesized from ADP in the electron transport chain. Given that molecules cannot go from a lower energy to a higher energy on their own without an external input of energy, how does the energy for this reaction enter the system?
Energy enters the system when NADH and FADH2 carry their high-energy electrons to the electron transport chain where, through chemiosmosis, their energy is used to transport hydrogen ions across the membrane into the intermembrane space, causing the buildup of a charge difference.
Yasmine is asked to describe the structural organization of chloroplasts. She writes the following sentence: "A chloroplast contains thylakoid stacks, called stroma, that are surrounded by fluid-filled grana." Which change to the sentence is necessary to make the sentence accurate?
Exchange the positions of "stroma" and "grana."
Organelles and materials needed for DNA synthesis are made
G1 Phase
Proteins and other materials needed for cell division are synthesized.
G2 Phase
Xavier and Jill are practicing the 100-meter sprint. Which statement BEST describes the metabolic pathways their muscles will utilize to produce the quick energy needed for this intense exercise?
Glycolysis begins glucose metabolism, and in the absence of oxygen, lactic acid fermentation takes over.
Celeste and Raymond are studying the differences between prokaryotes and eukaryotes. They learn that in eukaryotic cells the electron transport chain is in a different location than in prokaryotic cells. Which statements give the correct explanation of this difference?
In eukaryotes, the electron transport chain is composed of a series of electron carriers located in the inner membrane of the mitochondrion, In prokaryotes, the electron transport chain is in the cell membrane.
Can observe living algae
Light Microscope
Is the less expensive option
Light Microscope
What BEST describes the role of light in the overall process of photosynthesis?
Light provides the energy for assembling small molecules into sugars.
Lysosomes are organelles that contain enzymes. Which of the following is a function of lysosomes?
Lysosomes break down lipids, carbohydrates, and proteins.
Chromatids are distributed to the two daughter nuclei.
M Phase
During the light-dependent reactions of photosynthesis, which event must occur for ATP synthase to function properly?
Molecular oxygen must combine with ATP synthase.
The cells are differentiated and specialized.
Normal cell
The cells have a normal nucleus.
Normal cell
The cells undergo metastasis.
Normal cell
Mature mammalian red blood cells, called erythrocytes, have no nucleus, ribosomes, or mitochondria. The cytoplasm of erythrocytes is rich in hemoglobin, the protein that carries oxygen. The large amount of hemoglobin allows the red blood cells to carry the large amount of oxygen cells need for the high rate of metabolism in mammals. Erythrocytes have a biconcave shape, meaning they are thinner in their center than along their edges as shown in the model. Based on the structure of erythrocytes, how do red blood cells help to maintain homeostasis in mammalian organisms?
Oxygen diffuses into and out of red blood cells to maintain homeostasis. The biconcave shape of erythrocytes provides an increased surface area on the cells for diffusion to occur.
Does not use cellular energy
Passive transport
Particles move from an area of high concentration to an area of low concentration
Passive transport
Plants depend on a wide variety of carbon compounds, including carbohydrates, lipids, and proteins. What BEST describes the role of photosynthesis in producing these compounds?
Photosynthesis produces 12-carbon molecules that can be broken apart into smaller compounds.
The overall reactions for photosynthesis and cellular respiration are opposite of each other. Select two statements that describe the two processes.
Photosynthesis uses carbon dioxide from the atmosphere and produces oxygen, Cellular respiration uses oxygen to release energy from food and produces carbon dioxide as a by-product.
A number of scientists made contributions to cell theory. Which scientist was the first to use a light microscope to observe cells in a slice of cork?
Robert Hooke
At the end of this phase, each chromosome is made up of two chromatids
S Phase
Forms images of the surfaces of cells, not the interior
Scanning Electron Microscope
Has the higher magnification power
Scanning Electron Microscope
Requires placing algae cells in a vacuum
Scanning Electron Microscope
ATP is produced in all stages of cellular respiration. Which two statements describe the process of ATP synthesis in the electron transport chain?
The ATP synthase spins when the hydrogen ions rush past, acting as a "matchmaker" and grabbing another phosphate group to attach to an ADP molecule.
The process of combustion, or burning, is similar to the chemical processes that release energy in cells. Wood burns at a very high temperature, about 600°C. Which two statements explain how the human body is able to obtain energy without becoming too hot?
The breakdown of glucose occurs in many small steps, Low-temperature breakdown of glucose is enabled by enzymes that catalyze specific reactions.
Which of the following happens when cancer occurs?
The control of the cell cycle is impaired.
Mariana eats an orange. Which statement describes the ultimate source of the energy that her body receives when she digests the orange?
The light energy that originates from the sun provides the energy to grow oranges, which contain macromolecules.
The illustration shows a model of the transport of solute particles from outside the cell to inside the cell. What type of cell transport is modeled?
The model illustrates active transport because energy is required for solute particles to cross the cell membrane.
The model shows a substance crossing a cell membrane.
The model shows the process of active transport because the solute particles are moving from an area of low concentration to an area of high concentration.
Multicellular organisms contain organ systems. Which of the following BEST describes the organs in an organ system?
The organs in an organ system are made up of similar cells.
Researchers have been developing an artificial leaf, a device that mimics the actions of photosynthesis. The artificial leaf harnesses the energy of sunlight and uses it to provide energy for a series of chemical reactions. Potential products include hydrogen gas (H2) and methane gas (CH4). What is one way that the chemical processes of the artificial leaf are similar to photosynthesis?
The products contain high-energy chemical bonds.
If a cubical cell with 2-cm sides doubles the dimensions of its sides, what change occurs to the ratio of its surface area to volume?
The ratio is halved.
Chlamydomonas is a genus of single-celled photosynthetic algae. Which of the following is NOT a way that chlamydomonas maintains homeostasis?
The reproductive system of chlamydomonas contains specialized cells that enable the organism to reproduce both sexually and asexually.
What BEST describes the roles of photosystem I and photosystem II in the process of photosynthesis?
They absorb sunlight and transfer the energy to electrons.
Under normal conditions, gases diffuse through small holes in the leaves of a plant. When the weather is very hot and dry, plants may close these openings to conserve water. How are the closures most likely to affect photosynthesis?
They decrease the rate of photosynthesis by preventing carbon dioxide from entering the leaf.
Which of the following statements are typical for cancer cells? Select all that apply.
They tend to be unspecialized, They may form tumors that metastasize, They have defective genes.
In the process of glycolysis, four ATP molecules are synthesized from four ADP molecules. Why does glycolysis not yield four molecules of ATP?
Two ATP molecules are lost in the cytoplasm.
Glycolysis is the first stage of cellular respiration and is an anaerobic process. During glycolysis, glucose is converted to two molecules of pyruvic acid. How is glycolysis kept functioning during cellular respiration?
Two molecules of ATP from the cell are invested at the beginning of the process of glycolysis.
A cell is placed in an isotonic solution. How does the cell maintain homeostasis in this environment?
Water will move across the cell membrane to the inside of the cell because the cell has a higher concentration of solute particles than the solution.
White blood cells, called leukocytes, are very different in structure and function than red blood cells. White blood cells help fight infections, parasites, and bacteria. They do this by engulfing pathogens and synthesizing antibodies. Unlike red blood cells, white blood cells can reproduce.
White blood cells have a rough endoplasmic reticulum so that large molecules, such as antibodies, can be synthesized, White blood cells have a nucleus to store the coded instructions for reproducing and synthesizing important molecules.
Includes endocytosis and exocytosis
active transport
Natasha is making a model of cellular respiration. Her model shows the pathway followed when there is enough oxygen available. What does Natasha's model show?
an aerobic pathway consisting of glycolysis, the Krebs cycle, and the electron transport chain
The diagram shows the structure of adenosine diphosphate (ADP). What describes the conversion of ADP to ATP?
an input of energy to attach a third phosphate group
The p53 protein is involved in DNA repair and in triggering cell death when repair is not possible. Why are some cancers associated with defective p53 genes? Select all that apply.
because cells with damaged DNA are not triggered to die
The cells have an abnormal nucleus.
cancer cell
Which is the role of the electron transport chain in the process of photosynthesis?
carrying electrons from photosystem II, to photosystem I, to NADP+
Stuart is listing the changes to matter and energy that occur during the process of photosynthesis. Which of these examples should he include in his list?
chemical changes that convert carbohydrates into smaller molecules
Nancy is explaining why chlorophyll is classified as a plant pigment and how it is useful in photosynthesis. Which property of chlorophyll would be most appropriate for her to cite?
chlorophyll's ability to absorb light
If the side of a cubical cell doubled, what would the cell then require? Select all the correct answers.
eight times more nutrients, to excrete eight times more waste
During photosynthesis, what best describes the role of the compound with the chemical formula C6H12O6?
either a product or a reactant, depending on whether the cell needs to store energy or release energy
Daniel is developing a model of the light-independent reactions of photosynthesis, also known as the Calvin cycle. How should the model show how carbon compounds enter and exit the cycle?
enter as carbon dioxide, exit as 3-carbon molecules
The cells of all organisms contain DNA. In cells of which of the following groups is the cellular DNA enclosed in a nucleus?
eukaryotes
Xavier is describing the role of electron carriers, such as NADP+, in photosynthesis. Which property of NADP should Xavier cite?
its ability to accept and release high-energy electrons and a hydrogen ion
Like animals, plants contain a hierarchical organization of interacting systems. Which of the following is an example of an organ in a plant?
leaf
Which of the following structures are typically present in both plant and animal cells?
mitochondria
Microscopes can be used to explore cells. Which of the following types of microscopes is used to produce a three-dimensional image of the surface of a cell?
scanning electron microscope
The Krebs cycle consists of many small steps, each catalyzed by an enzyme. What is another name for the Krebs cycle?
the citric acid cycle
Savannah is asked to explain the locations of the stages of cellular respiration. What location should she give for the site of the Krebs cycle reactions?
the matrix of the mitochondria
Which organelles allow plants to support heavy structures such as leaves and flowers?
the vacuoles because they are filled with fluid, which provide rigidity
Why do cells divide? Select all that apply.
to produce new cells during an organism's growth, to replace damaged cells and tissues
Particles move from an area of low concentration to an area of high concentration
Active transport
Requires cellular energy
Active transport
Jose and Rema are making sourdough bread. They have been feeding the starter dough for a week now, and it has undergone lactic acid fermentation. They mix the dough and add a portion of the starter, which will give the bread its famous texture and sour flavor. What process will occur next to make the dough rise?
Alcoholic fermentation takes place and ethyl alcohol and CO2 gas are formed, creating pockets in the dough.
Which of the following statements is part of the cell theory?
All cells are produced from existing cells.
This process causes death of abnormal cells.
Apoptosis
This process decreases the number of body cells.
Apoptosis
This process regulates the cell cycle.
Apoptosis