Chapter 4 : Cells

molecules move spontaneously from an area of high concentration to an area of low concentration.

In passive transport: Please choose the correct answer from the following choices, and then select the submit answer button. ATP is required to move molecules against the concentration gradient. ATP is required to move especially large molecules or ions across a cell membrane. a transport protein moves one molecule against the concentration gradient, while another molecule moves down its gradient. molecules move spontaneously from an area of high concentration to an area of low concentration. molecules move from an area of low concentration to an area of high concentration.

exocytosis

Insulin is made by pancreatic cells, packaged in small vesicles, and then released into the bloodstream. This describes what sort of cell transport? Please choose the correct answer from the following choices, and then select the submit answer button. endocytosis pinocytosis exocytosis receptor-mediated endocytosis osmosis

winding a clock by hand; having the clock run on the stored energy from winding

Primary active transport is to secondary active transport as ______________ is to ______________. Please choose the correct answer from the following choices, and then select the submit answer button. a molecule moving alone across a membrane; a molecule moving together with another across a membrane winding a clock by hand; having the clock run on the stored energy from winding molecules moving down their concentration gradient directly across a phospholipid bilayer; molecules moving down their concentration gradient through a membrane transport protein oxygen moving across a membrane; carbon dioxide moving across a membrane walking; running

Protein A is a transmembrane protein; Protein B is a peripheral membrane protein.

Protein sequence A shows a string of leucines (hydrophobic amino acids) at one end, and a string of arginine (hydrophilic amino acids) at the opposite end. Protein sequence B contains purely hydrophilic amino acids. It is known that both proteins are membrane proteins. Which of the following statements best classifies Protein A and Protein B? Please choose the correct answer from the following choices, and then select the submit answer button. Protein A is a transmembrane protein; Protein B is a peripheral membrane protein. Protein A is a transmembrane protein; Protein B is a peripheral membrane protein that can only be situated on the inner side of the membrane. Protein A is a transmembrane protein; Protein B is a peripheral membrane protein that can only be situated on the outer side of the membrane. Protein A is a transmembrane protein; Protein B is also a transmembrane protein. Protein A is a surface protein; Protein B is a transmembrane protein.

active transport

Sodium is transported out of a cell through a transport protein from an area of lower concentration to an area of higher concentration with the use of ATP. Which type of membrane transport is involved in this process? Please choose the correct answer from the following choices, and then select the submit answer button. active transport receptor-mediated endocytosis facilitated diffusion simple diffusion osmosis

is void of water.

The inner region of a plasma membrane's phospholipid bilayer: Please choose the correct answer from the following choices, and then select the submit answer button. contains the head regions of the phospholipid molecules. stores hormones for future use. is void of water. has a net negative charge. has a high salt concentration.

Endosymbiosis refers to the engulfment of a prokaryotic cell that developed into an organelle, whereas invagination refers to the membrane folding in on itself and forming membranous organelles.

What is the difference between endosymbiosis and invagination? Please choose the correct answer from the following choices, and then select the submit answer button. Endosymbiosis is the best current theory for the origin of ribosomes. Endosymbiosis pertains to compatible organisms, whereas invagination refers to a relationship among completely different organisms. Endosymbiosis pertains to organelle evolution, whereas invagination refers to a mechanism by which organisms obtain food from their surroundings. Endosymbiosis involves the plasma membrane folding in on itself, whereas invagination refers to engulfment of another cell. Endosymbiosis refers to the engulfment of a prokaryotic cell that developed into an organelle, whereas invagination refers to the membrane folding in on itself and forming membranous organelles.

A pilus is an appendage that is used for prokaryotic attachment to surfaces, whereas a flagellum helps the prokaryote move.

What is the main difference between flagella and pili? Please choose the correct answer from the following choices, and then select the submit answer button. Both pili and flagella are the same thing, and the terms can be used interchangeably. A pilus is an appendage that is used for prokaryotic attachment to surfaces, whereas a flagellum helps the prokaryote move. A pilus is used to help prokaryotes and eukaryotes move; a flagellum only helps prokaryotes move. A flagellum is considered an appendage; a pilus is not. Pili are found in eukaryotes, whereas flagella are unique to prokaryotes.

They separate chemicals into different compartments, concentrating them for certain reactions.

What major advantage does the presence of organelles offer eukaryotic cells? Please choose the correct answer from the following choices, and then select the submit answer button. They separate chemicals into different compartments, concentrating them for certain reactions. They help make eukaryotic cells larger. They help to blend together the chemicals throughout the cell. They greatly simplify eukaryotic cells, making them less complex. They make eukaryotic cells stronger.

The salad dressing is hypertonic, so water diffuses out of the lettuce leaves' cells, causing the leaves to wilt.

When lettuce leaves are coated in salad dressing, they will wilt. Why? Please choose the correct answer from the following choices, and then select the submit answer button. The salad dressing prevents water loss, causing the lettuce leaves to wilt. The salad dressing is hypertonic, so water diffuses out of the lettuce leaves' cells, causing the leaves to wilt. The lettuce leaves' cells have a high salt concentration, so water diffuses from the salad dressing into the leaves, causing them to wilt. The salad dressing is hypotonic and pushes water into the lettuce leaves' cells, causing the leaves to wilt. The cells in the lettuce leaves have a lower solute concentration than the salad dressing, so they absorb water, which causes the leaves to wilt.

plasmodesmata: nerve cells

Which of the following cell connections is incorrectly matched with its location in living organisms? Please choose the correct answer from the following choices, and then select the submit answer button. tight junctions: small intestines desmosomes: muscle tissue gap junctions: cardiac tissue plasmodesmata: plant cells plasmodesmata: nerve cells

Mitochondria and chloroplasts both have small, circular pieces of DNA.

Which of the following characteristics supports the theory that mitochondria and chloroplasts were once independent prokaryotic cells? Please choose the correct answer from the following choices, and then select the submit answer button. Mitochondria and chloroplasts both produce energy for the cell. Mitochondria and chloroplasts both have small, circular pieces of DNA. Mitochondria and chloroplasts are both found in plant cells. Mitochondria and chloroplasts are membrane-bound organelles. Mitochondria and chloroplasts store proteins.

a liver cell recognizing and engulfing an LDL molecule

Which of the following describes receptor-mediated endocytosis? Please choose the correct answer from the following choices, and then select the submit answer button. chloride entering a trachea cell via a transport protein the ends of neural cells releasing neurotransmitters sodium and potassium ions being pumped across a cell membrane white blood cells engulfing an invading bacterium a liver cell recognizing and engulfing an LDL molecule

Oxygen moves through the cell membrane from an area of high concentration outside the cell into an area of lower concentration inside the cell.

Which of the following describes simple diffusion? Please choose the correct answer from the following choices, and then select the submit answer button. Hydrogen ions are pumped out of stomach lining cells with the use of ATP. Oxygen moves through the cell membrane from an area of high concentration outside the cell into an area of lower concentration inside the cell. The salts in a laxative cause water to move from surrounding cells into the intestines. Sodium is transported out of the cell to an area of lower concentration with the use of ATP. Glucose is transported into the cell via a transport protein.

Passive transport may involve chemical energy in the form of ATP.

Which of the following is not a correct statement about passive transport across the cell membrane? Please choose the correct answer from the following choices, and then select the submit answer button. Passive transport decreases free energy. Passive transport may involve chemical energy in the form of ATP. Passive transport increases entropy in a system. Facilitated diffusion by transport proteins is one form of passive transport. Diffusion across an electrochemical gradient is one form of passive transport.

the cytoskeleton

Which of the following is not part of the endomembrane system? Please choose the correct answer from the following choices, and then select the submit answer button. the Golgi apparatus the rough endoplasmic reticulum the smooth endoplasmic reticulum the cytoskeleton All of the above are part of the endomembrane system.

carbohydrate chains: provide a "fingerprint" for the cell so it can be identified by other cells

Which of the following membrane molecules is correctly matched to its function? Please choose the correct answer from the following choices, and then select the submit answer button. cholesterol: binds to external chemicals in order to regulate processes within the cell transport proteins: catalyze intra- and extracellular reactions on the plasma membrane receptor protein: helps the plasma membrane retain flexibility recognition protein: provides a passageway that allows polar or charged substances to pass through the plasma membrane Correct: carbohydrate chains: provide a "fingerprint" for the cell so it can be identified by other cells carbohydrate chains: provide a "fingerprint" for the cell so it can be identified by other cells

Vacuoles function as storage spaces and also play a role in plant nutrition, waste management, predator deterrence, reproduction, and physical support.

Which of the following properly describes the role of vacuoles? Please choose the correct answer from the following choices, and then select the submit answer button. Vacuoles are involved in nutrient storage as well as waste management for plants. Correct: Vacuoles function as storage spaces and also play a role in plant nutrition, waste management, predator deterrence, reproduction, and physical support. Vacuoles function as storage spaces and also play a role in plant nutrition, waste management, predator deterrence, reproduction, and physical support. Vacuoles function to connect cells and enable communication and transport between them. Vacuoles help provide physical support to plants, allowing stems, flowers, and other plant parts to stand upright. Vacuoles are empty sacs within a plant cell that simply provide structure.

The stacks of interconnected sacs within the chloroplast are known as thylakoids; the light-collecting for photosynthesis occurs here.

Which of the following statements about chloroplasts is true? Please choose the correct answer from the following choices, and then select the submit answer button. The chloroplast has one single membrane layer due to its small size. The DNA of the chloroplast is found within the thylakoid sacs. Chloroplasts are found in eukaryotic cells, therefore they contain linear DNA. The stacks of interconnected sacs within the chloroplast are known as thylakoids; the light-collecting for photosynthesis occurs here. The stacks of interconnected sacs within the chloroplast are known as stroma; this is where the light-collecting for photosynthesis occurs.

Both the Golgi apparatus and the endoplasmic reticulum work together to form the endomembrane system.

Which of the following statements about the endoplasmic reticulum and the Golgi apparatus is true? Please choose the correct answer from the following choices, and then select the submit answer button. Both the Golgi apparatus and the endoplasmic reticulum work together to form the endocytotic and exocytotic cycles of the cell. The Golgi apparatus is connected to the endoplasmic reticulum via tight junctions. Both the Golgi apparatus and the endoplasmic reticulum work together to form the endomembrane system. Not all eukaryotic cells contain an endomembrane system; only those involved in transporting materials possess this system. The Golgi apparatus is a site of processing and packaging only; the endoplasmic reticulum is responsible for synthesizing compounds such as carbohydrates.

The nucleus contains pores that only open in response to DNA entering or exiting the cell.

Which of the following statements about the nucleus is false? Please choose the correct answer from the following choices, and then select the submit answer button. The nucleus contains pores that only open in response to DNA entering or exiting the cell. The nucleus acts as the genetic control center of the cell, directs all cellular activity, and stores hereditary information. The nucleus consists of two bilayers, layered one on top of the other. The nucleus contains three important structural components: the nuclear membrane, chromatin, and the nucleolus. Ribosomes are assembled inside of the nucleu

Water moves from an area of high solute concentration in our extracellular fluid to an area of lower solute concentration in our cells.

Which of the following statements correctly describes osmosis? Please choose the correct answer from the following choices, and then select the submit answer button. Water moves from an area of high solute concentration in our extracellular fluid to an area of lower solute concentration in our cells. Glucose moves from an area of high concentration outside a cell to an area of low centration inside the cell, where it is used to generate energy. Nutrients move from an area of high concentration in our digestive tract to an area of low concentration in the blood vessels of our digestive tract. Cellular waste moves from an area of high concentration inside the cell to an area of lower concentration outside the cell. Oxygen moves from an area of high concentration in the air to an area of low concentration in the blood vessels of our lungs.

The molecules that make up the membrane are phospholipids.

Which of the following statements is true about a plasma membrane? Please choose the correct answer from the following choices, and then select the submit answer button. It is composed of a single layer of phospholipids. The molecules that make up most of the plasma membrane are polar at their heads and tails. It is a rigid structure that protects the cell like a shell. The molecules that make up the membrane are phospholipids. The molecules making up the plasma membrane are locked in place.

red blood cells

Which of the following types of human cells does not contain DNA? Please choose the correct answer from the following choices, and then select the submit answer button. liver cells muscle cells red blood cells skin cells brain cells

moving testosterone produced within a testicular cell into the bloodstream

Which of the following would be performed by a transport protein in the cell membrane? Please choose the correct answer from the following choices, and then select the submit answer button. binding to adrenaline on heart cells, thereby increasing the heart's rate of contraction recognizing and ingesting a cold virus moving testosterone produced within a testicular cell into the bloodstream initiation of an immune system response upon identifying a foreign cell maintaining the flexibility of the cell membrane

too much adrenaline binding to membrane beta-receptors.

Cystic fibrosis is to "faulty chloride ion transport," as anxiety and high blood pressure are to: Please choose the correct answer from the following choices, and then select the submit answer button. the inability of immune cells to recognize the proteins on a cell's surface. too much adrenaline binding to membrane beta-receptors. too much cholesterol in the membrane. beta-blockers. too much mucus accumulating in the lungs.

occurs without the input of energy.

Diffusion across the cell's outer membrane: Please choose the correct answer from the following choices, and then select the submit answer button. occurs without the input of energy. is also called dynamic equilibrium. never occurs; all molecules cross the membrane within protein carriers. always results with the molecules moving from areas of low concentration to areas of high concentration. requires ATP.

binding to the cytoplasmic (intracellular) side of a receptor protein.

Drugs called beta-blockers do all of the following except: Please choose the correct answer from the following choices, and then select the submit answer button. preventing adrenaline from doing its job. binding to the cytoplasmic (intracellular) side of a receptor protein. reducing outward symptoms of anxiety. blocking signaling through adrenaline receptors. reducing high blood pressure.

DNA

Mitochondria contain circular strands of ____, similar to that found in many prokaryotes.

tight junctions; desmosomes

Modern airplanes are built with waterproof seals around the windows and rivets are used to hold the metal sheets to the frame, forming the fuselage. The waterproof seals are to rivets as ________ are to __________ . Please choose the correct answer from the following choices, and then select the submit answer button. gap junctions; tight junctions desmosomes; tight junctions desmosomes; plasmodesmata plasmodesmata; gap junctions tight junctions; desmosomes

lack a nucleus.

Prokaryotes: Please choose the correct answer from the following choices, and then select the submit answer button. are more complex than eukaryotes. evolved after eukaryotes. are multicellular. lack a plasma membrane. lack a nucleus.

animal; plant

The figure shown on the left is a(n) __________ cell, whereas the cell on the right is a(n) __________ cell. Please choose the correct answer from the following choices, and then select the submit answer button. bacterial; animal eukaryotic; prokaryotic archaeal; bacterial animal; plant plant; bacterial

a glycerol linked to a phosphorus-containing molecule

The hydrophilic head of the cell membrane is composed of: Please choose the correct answer from the following choices, and then select the submit answer button. enzymatic proteins. a glycerol linked to a phosphorus-containing molecule. cellulose. carbon-hydrogen chains. cholesterol.

cell

The most basic unit of any organism is the ____.

is hydrophobic and nonpolar.

The tail portion of an individual phospholipid molecule: Please choose the correct answer from the following choices, and then select the submit answer button. is hydrophobic and polar. is hydrophilic and nonpolar. contains bonds with unequal sharing of electrons. is hydrophobic and nonpolar. is hydrophilic and polar.

osmosis.

The transport of water across a membrane from a solution of lower solute concentration to a solution of higher solute concentration is best described as: Please choose the correct answer from the following choices, and then select the submit answer button. facilitated diffusion. active transport. osmosis. receptor-mediated transport. secondary active transport.

plasma membrane

What cellular structure makes it possible for a cell to differ structurally and biochemically from its surroundings? Please choose the correct answer from the following choices, and then select the submit answer button. nucleus cell wall phospholipid endoplasmic reticulum plasma membrane

They contain circular DNA.

What feature of chloroplasts suggests that they are derived from photosynthetic bacteria? Please choose the correct answer from the following choices, and then select the submit answer button. They contain thylakoids. They have a nucleus. They are filled with stroma. They contain circular DNA. They contain a central vacuole.

2 billion years ago

How long ago did eukaryotic cells evolve? Please choose the correct answer from the following choices, and then select the submit answer button. 2 million years ago 3.5 billion years ago 6,000 years ago 4.5 billion years ago 2 billion years ago

isotonic

If the solution surrounding a cell contains the same amount of solute as the cytoplasm, the osmotic condition is said to be _________.

nuclear

The ______ membrane surrounds the nucleus and separates it from the cytoplasm

Robert Hooke

Question Value: 15 points Who was the first scientist to use the term "cell"? Please choose the correct answer from the following choices, and then select the submit answer button. Antonie van Leeuwenhoek Francis Crick Charles Darwin Robert Hooke Gregor Mendel

a beta-blocker.

A drug that alters membrane function and serves to reduce anxiety is called: Please choose the correct answer from the following choices, and then select the submit answer button. adrenaline. a beta-receptor. caffeine. a beta-blocker. alcohol.

All of the above.

Cilia: Please choose the correct answer from the following choices, and then select the submit answer button. are microtubule-based structures. are short projections. help the cell move through its environment. when they are present, occur in large numbers on a single cell. All of the above.

prokaryotes and eukaryotes

Every cell on earth can be classified into one of which two categories? Please choose the correct answer from the following choices, and then select the submit answer button. unicellular and multicellular reproductive and nonreproductive prokaryotes and eukaryotes archaea and prokaryotes bacteria and mammalian

The membrane is impermeable to the solute, so water moves in and out of the cell to maintain a concentration equilibrium between the interior and exterior of the cell.

How is osmosis across the cellular membrane controlled? Please choose the correct answer from the following choices, and then select the submit answer button. Solute moves freely, into and out of the cellular membrane, carrying water along with it. The interior of the cell receives chemical signals triggered by the glycoproteins outside the cell to tell it when to let water out or take water in. The membrane is impermeable to the solute, so water moves in and out of the cell to maintain a concentration equilibrium between the interior and exterior of the cell. Water is "chaperoned" through the cellular membrane by transporting protein carriers. Osmosis does not occur across the cellular membrane, so it cannot be controlled.

Transmembrane proteins remain in the plasma membrane even though they are not attached to anything.

In chemistry class we learn the rule "like dissolves like" when studying why polar substances dissolve in each other (like sucrose in water) and why nonpolar substances dissolve in each other (like fats in oil). Which of the following statements illustrates this rule? Please choose the correct answer from the following choices, and then select the submit answer button. Ribosomes are found inside of prokaryotic cells rather than outside. More prokaryotic cells could fit inside a 1 cm cube than eukaryotic cells could. Chemical messengers or hormones bind tightly to their receptor proteins on the outside of a cell. Transmembrane proteins remain in the plasma membrane even though they are not attached to anything. Prokaryotes lack a nuclear membrane while eukaryotes have one.

facilitated diffusion.

Polar molecules and many charged molecules like water, ions, amino acids, and sugars pass across the membrane via: Please choose the correct answer from the following choices, and then select the submit answer button. facilitated diffusion. membrane transport. protein-mediated exchange. endocytosis. exocytosis.

is addicted to prescription painkillers.

Proliferation of the smooth ER is likely in an individual who: Please choose the correct answer from the following choices, and then select the submit answer button. has just started lifting weights. is addicted to prescription painkillers. lacks rough ER in their cells. works outdoors in a cold temperatures. is training to run a marathon.

chloroplasts.

The cell organelles most analogous to mitochondria are: Please choose the correct answer from the following choices, and then select the submit answer button. ribosomes. the Golgi apparatus. peroxisomes. lysosomes. chloroplasts.

gives animal cells shape and support.

The cytoskeleton: Please choose the correct answer from the following choices, and then select the submit answer button. gives animal cells shape and support. gives plant cells shape and support. controls the extracellular traffic flow. produces no force and is unrelated to cell movement. All of the above are correct.

phagocytosis, pinocytosis, and receptor-mediated endocytosis

What are the three types of endocytosis? Please choose the correct answer from the following choices, and then select the submit answer button. phagocytosis, pinocytosis, and exocytosis vesicles, LDL particles, and receptors vesicles, LDL particles, and HDL particles phagocytosis, pinocytosis, and receptor-mediated endocytosis plasmocytosis, pinocytosis, and exocytosis

microtubules, intermediate filaments, and microfilaments

What are the three types of protein fibers that make up the cytoskeleton? Please choose the correct answer from the following choices, and then select the submit answer button. microtubules, intermediate filaments, and microfilaments cilia, intermediate filaments, and microfilaments large, intermediate, and small microfilaments tubules, filaments, and flagella There are actually four types of protein fibers that make up the cytoskeleton.

Facilitated diffusion requires the help of a transport protein.

What characteristic makes facilitated diffusion different from simple diffusion? Please choose the correct answer from the following choices, and then select the submit answer button. Facilitated diffusion requires the help of a transport protein. Simple diffusion moves molecules down a concentration gradient. Facilitated diffusion moves molecules against a concentration gradient. Facilitated diffusion requires the input of ATP. Simple diffusion only involves the movement of water across a semipermeable membrane.

maintains membrane flexibility

What is the function of cholesterol in the plasma membrane? Please choose the correct answer from the following choices, and then select the submit answer button. maintains membrane flexibility harvests energy synthesizes proteins controls what passes into and out of a cell provides intercellular communication

mitochondria

Which of the following organelles contains a small circular loop of DNA? Please choose the correct answer from the following choices, and then select the submit answer button. mitochondria nucleus smooth endoplasmic reticulum lysosomes Golgi apparatus

Plants have chloroplasts instead of mitochondria.

Which statement about chloroplasts and mitochondria is false? Please choose the correct answer from the following choices, and then select the submit answer button. Plants have chloroplasts instead of mitochondria. Chloroplasts produce food from sunlight energy. Animal cells do not contain chloroplasts. Both mitochondria and chloroplasts are involved with energy transformation. Mitochondria break down food energy to make ATP.

They provide plant cells with incredible structural strength

Which statement is true about plant cell walls? Please choose the correct answer from the following choices, and then select the submit answer button. They provide plant cells with incredible structural strength. They are the location of photosynthesis in plants. They are made largely from chitin. They serve to retain and degrade waste products. They are filled with stroma.

Vesicles

______________ are found in all metabolically active cells and are involved primarily in transporting materials within, into, and out of cells. Please choose the correct answer from the following choices, and then select the submit answer button. Vesicles Lysosomes Vacuoles Peroxisomes Mitochondria