A&P Ch3 HW Cells and Tissues PDF

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Cells and Tissues...

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Chapter 3

1. A large amount of extracellular material is a characteristic of which type of tissue?

muscle tissue epithelium connective tissue nervous tissue 2.

3- A. Which of the following best explains diffusion?

exchange of nonpolar molecules for polar molecules movement of molecules from an area of high concentration to an area of low concentration movement of molecules from where there are fewer of them to where there are more movement of molecules farther away from equilibrium Correct

By diffusion, molecules spread out to maximize their space.

3-B. Which of the following is most likely to move through the cell membrane by facilitated diffusion?

O2 small lipids Na+ CO2 All attempts used; correct answer displayed Ions move easily through water, which is polar, but cannot pass directly through the lipid (nonpolar) part of the cell membrane.

3-C. What is the basic difference between simple diffusion and facilitated diffusion across a cell membrane?

Simple diffusion is passive but facilitated diffusion is an active process that uses energy. Simple diffusion requires molecules to move through special doorways in the cell membrane. In simple diffusion, molecules move down the concentration gradient but in facilitated diffusion molecules move up the concentration gradient. In facilitated diffusion, molecules only move with the aid of a protein in the membrane. Correct Facilitated diffusion allows molecules that cannot pass through the lipid component of the membrane to pass through via a more compatible protein channel or carrier. This includes ions and polar molecules.

3-D. Which of the following is least likely to increase the rate of diffusion?

small concentration gradient higher concentration of molecules high temperature small molecule size Correct

The larger the concentration gradient, the faster the rate of diffusion. Higher concentration means there are more collisions, so the molecules bounce away from each other more rapidly.

4. The cells in our bodies are made up primarily of which four elements?

hydrogen, nitrogen, calcium, and oxygen sodium, potassium, chloride, and calcium carbon, hydrogen, oxygen, and nitrogen hydrogen, nitrogen, sodium, and oxygen

5. Which of the following molecules brings the appropriate amino acid to the ribosome during protein synthesis?

ribosomal RNA messenger RNA transfer RNA DNA 6. Which cell junctions prevent substances from passing between adjacent cells?

desmosomes gap junctions tight junctions anchoring junctions 7. Which organelle synthesizes proteins that are used in the cytoplasm?

rough endoplasmic reticulum (RER)

ribosomes that are free within the cytoplasm Golgi apparatus mitochondria 8. What is the significance of granulation tissue?

It is seen with aging. It is found in embryos. It formed during tissue repair. It is a type of connective tissue.

9-A. Which of the following lists, in correct order, the phases of interphase?

G1, prophase, and S S, cytokinesis, mitosis Prophase, metaphase, telophase G1, S, and G2 Correct In addition to providing time for the cell to do its usual jobs, the phases of interphase prepare the cell for cell reproduction, which follows

9-B. Which of the following lists, in correct order, the phases of mitosis?

prophase, anaphase, metaphase, telophase prophase, metaphase, anaphase, cytokinesis interphase, prophase, metaphase, anaphase, telophase prophase, metaphase, anaphase, telophase

Correct Some students recall the order of the stages by remembering “PMAT,” which uses the initial from each phase in order. Another way to remember the order is this phrase: “I pee more after tea

9-C. During which of the following phases does DNA replication occur?

Synthesis cytokinesi s prophase mitosis Correct Synthesis is part of interphase, and is completed well before the cell actually divides.

9-D. During which of the following phases does chromatin condense and become chromosomes?

prophase anaphase interphase metaphas e Correct The chromatin condenses into rodlike chromosomes during prophase in preparation for dividing the DNA. Chromosomes are present from late prophase until telophase, when they relax and return to the chromatin state.

10. Which type of tissue is NOT readily repaired if damaged?

epithelial tissue

tissues whose cells remain mitotic throughout life liver tissues whose mature cells are amitotic

11. Which of these organelles is responsible for forming secretory vesicles?

lysosomes Golgi apparatus rough endoplasmic reticulum (RER) smooth endoplasmic reticulum (SER) 12-A. A primary active transport process is one in which __________.

the plasma membrane folds inward to form a vesicle containing extracellular material molecules move through transport proteins that have been activated by ATP molecules pass directly through the phospholipid bilayer of the plasma membrane molecules move across the plasma membrane without an input of energy an intracellular vesicle fuses with the plasma membrane and releases its contents to the extracellular fluid Correct Yes! You've got it! Primary active transporters, such as the sodium-potassium ATPase (or pump), are activated when ATP is hydrolyzed. This activation allows for the transport of solutes across the plasma membrane against concentration gradients.

12-B.Some transport processes use transport proteins in the plasma membrane, but do not require ATP. This type of transport is known as _____.

active transport

simple diffusion exocytosis endocytosis facilitated diffusion Correct Yes! You've got it! Facilitated diffusion is a passive transport process during which molecules move down their concentration gradients through transport proteins.

12- C The majority of water molecules moving across plasma membranes by osmosis do so via a process that is most similar to ____.

cotransport a process that requires energy from the cell active transport simple diffusion facilitated diffusion Correct Yes! You've got it!

12- D The sodium-potassium pump uses ATP to move sodium and potassium ions across the plasma membrane. This statement describes _____.

primary active transport facilitated diffusion simple diffusion exocytosis secondary active transport Correct Yes! You've got it! The sodium-potassium pump is activated by ATP. This activation allows the pump to transport sodium and potassium ions against their gradients.

12-E A vesicle fuses with the plasma membrane and releases its contents to the extracellular fluid. This statement describes _____.

endocytosis facilitated diffusion active transport exocytosis simple diffusion Correct Yes! You've got it! The term exocytosis literally means "out of the cell."

13 A During which phase of the cell cycle does DNA duplication, or replication, take place?

Prophase Interphase Metaphas e Anaphase Correct Yes! DNA replicates during interphase. This process provides each new daughter cell with a full complement of genetic material.

13 B

Part complete When a double helix of DNA is replicated, two complete helices are formed. Together, these helices are called sister __________.

centromeres telomeres chromatids chromosomes Correct Yes! Each new daughter cell receives one of the sister chromatids. After the chromatids separate, each is considered a new chromosome. At the end of cell division, each new cell contains 23 pairs of chromosomes.

13 C During which phase of mitosis do sister chromatids line up at the center of the cell?

Telophase Metaphas e Prophase Anaphase Correct Yes! Spindle microtubules from both poles of the cell attach to the sister chromatids and pull them in both directions. During metaphase, the sister chromatids are forced to the center of the cell.

13 D During which phase of mitosis do the sister chromatids move apart?

Prophase Metaphas e Telophase Anaphase Correct

Yes! During anaphase, the centromeres split and the spindle microtubules pull the sister chromatids to opposite poles of the cell. The single chromatids are now considered chromosomes.

13 E During which phase of mitosis do nuclear envelopes and the nucleoli reappear?

Prophase Telophase Anaphase Metaphas e

Correct Yes! Telophase begins when the chromosomes stop moving. Nuclear envelopes form, and nucleoli reappear. Ultimately, the cell divides in two by a process known as cytokinesis.

13 F During which phase of mitosis do the nuclear envelope and nucleoli disappear?

Prophase Metaphas e Anaphase Telophase Correct Yes! Prophase is the first phase of mitosis. During this phase, the sister chromatids condense, the nuclear envelope and nucleoli disappear, and the spindle apparatus forms.

13 G What is the name of the process by which the cytoplasm divides in two?

Cytoplasmic streaming Microtubule shortening Cytokinesis Segregation

Correct Yes! During cytokinesis, a ring of actin and myosin filaments contract to form a cleavage furrow and the cell divides in two.

14 A Which of the following is the main component of the cell membrane?

carbohydrates cholesterol water phospholipid s Correct Although phospholipids have a polar head, the long fatty acid tails are nonpolar, making the membrane mostly nonpolar.

14 B Which of the following is a characteristic of the cell membrane?

impermeable semipermeable fully permeable not permeable Correct The cell membrane is semipermeable, or selectively permeable, because some things can easily pass through it while others cannot.

14C Which of the following is not a major function of proteins in the cell membrane?

acting as receptors anchoring cells to other structures forming channels

forming the entire glycocalyx Correct The glycocalyx is composed mostly of carbohydrates.

14 D What part of a cell membrane is usually in contact with the interstitial fluid?

cholesterol hydrophobic molecules phosphate heads of phospholipids fatty acid tails Correct The phosphate heads of the phospholipids are polar, so they are attracted to the polar water molecules

15 A Which of the following is not required for osmosis to occur?

water selectively permeable membrane cellular energy concentration gradient Correct Osmosis is a special type of diffusion, which is always a passive process.

15 B Which of the following solutions contains the most solute?

isotonic

hypertonic equilibriu m hypotonic Correct “Hyper” means “high,” so a hypertonic solution has a higher solute concentration than the solution to which it is being compared.

15 C In general, to maintain homeostasis the relationship between our intracellular and extracellular fluids should be which of the following?

intracellular and extracellular should both be hypertonic intracellular should be hypotonic to extracellular isotonic to each other intracellular should be hypertonic to extracellular Correct In order to prevent the cells from either swelling or shrinking, the body fluids should be isotonic, meaning that they are at equilibrium.

15D If a person is severely dehydrated, their extracellular fluids will become hypertonic to the intracellular fluid. What do you predict will happen to the person’s cells?

Extracellular fluids do not impact cell size, because cells contain intracellular fluid. The cells will rupture. The cells will lose water and shrink. The cells will swell. Correct The hypertonic extracellular fluid will draw water out of the hypotonic intracellular fluid, so the cells will shrink. This is called crenulation...