EXAM 2 Ch 3,4,5,6

How many atoms are present in a single molecule of C8H10N4O2?

24

Which statement is FALSE? Mitosis is required to halve the chromosome number. Mitosis is the process used to repair damaged tissues. Mitosis is required for embryonic development. Mitosis occurs during wound healing.

Mitosis is required to halve the chromosome number.

A long piece of ribbon wired along both long edges is twisted into a helix and wrapped around individual pipe cleaners that have been rolled into spools; this grouping is then twisted (super coiled) again to condense it. This could be best used as a simple model for

a chromosome, where the pipe cleaners represent bundles of proteins around which the DNA double helix (wired ribbon) is wrapped.

A factory with an office that controls the information sent to separate rooms for each of the manufacturing and shipping processes would be analogous to

a eukaryotic cell with a nucleus.

Metabolic reactions that break down complex molecules into smaller compounds, thereby releasing usable energy for the cell, are best described as

catabolic.

Which of the following could be built solely from glucose molecules?

starch

The pH scale measures

the concentration of hydrogen ions in a solution.

Of the following values, which indicates the MOST basic pH?

10 (highest number is the most basic)

Nitrogen has seven protons, seven neutrons, and seven electrons. What is the atomic mass of nitrogen?

14

Which of the following statements is the BEST description for plasma membranes?

A double layer of phospholipid molecules with the hydrophobic tails pointed towards each other

The molecule ________ is produced to store energy and is broken down in order to use that energy for cellular processes.

ATP

Which of the following is either consumed or synthesized in virtually every cellular reaction?

ATP

Plants doing photosynthesis use ______________ and produce/give off ___________, while Animals doing cellular respiration use ______________ and produce/give off _________________.

CO2, Oxygen, Oxygen, CO2

During which cellular process is ATP NOT released?

Calvin cycle

Which of the following statements most accurately describes a selectively permeable membrane?

Certain solutes move freely across the membrane by simple diffusion while others must be helped across by active or passive transport proteins; some substances are completely excluded from crossing the membrane.

Which of the following relationships between cell structures and functions is NOT correct?

Chloroplasts- chief site of respiration

Which of the following is/are part of accepted cell theory?

Every living organism is composed of one or more cells, and all living cells arise from preexisting cells.

The ________ is responsible for chemically tagging and packaging proteins and sometimes lipids for transport not only to specific locations within the cell but at times for transport to the exterior of the cell.

Golgi apparatus

Which of the following serves as both reactant in photosynthesis and product in cellular respiration?

H2O

The protons that make up the proton gradient used during the light reactions of photosynthesis come from

H2O.

Which of the following statements about cell division is correct? It is no longer necessary once an organism reaches maturity. It is the process by which fertilization occurs. It occurs in two sequential stages in all cells: mitosis and meiosis. It is the process by which organisms grow and maintain their tissues.

It is the process by which organisms grow and maintain their tissues.

The endoplasmic reticulum (ER) is a single membrane continuous with the nuclear envelope and a series of interconnected sacs throughout the cell. Why might it be beneficial to the cell for the ER to be continuous with the nuclear envelope?

It might be beneficial for the ER and nuclear envelope to be connected because it might make it easier for messages to get from the nucleus to the ER where proteins and lipids are made for the cell; this would most likely require the use of less energy.

For which of the following jobs is active transport most responsible?

Movement of molecules into or out of a cell against a concentration gradient

The Krebs cycle produces

NADH, ATP, and FADH2.

Which of the following is an ion? The amino acid, cysteine H2O O2 Na+

Na+

Which of the following accurately describes crossing over?

Paternal chromosome 7 exchanges segments of DNA with maternal chromosome 7

What is the importance of photosynthesis to organisms other than plants?

Photosynthesis captures energy that other organisms access when they eat either plants or organisms that eat plants.

Plant or animal? (photo of a group of purple dyed, rectangular shaped cells. the third cell is beginning to split)

Plant

Which of the following statements about energy metabolism is FALSE? Plants provide the H2O and CO2 that animals need to carry out respiration. All animals in some way rely on plants for their energy. The energy that powers living systems ultimately comes from the sun. The main objective of respiration is to break down glucose and make ATP.

Plants provide the H2O and CO2 that animals need to carry out respiration.

Replication of a cell's genetic material occurs during

S phase.

Dialysis tubing is a selectively permeable membrane that can be filled with a solution to simulate a cell. A piece of dialysis tubing has been filled with a cloudy white solution of 5 percent starch, 5 percent egg albumin (protein), and 5 percent glucose (a small sugar) dissolved in water to simulate a cell. This cell is weighed and then placed in a beaker of 3 percent iodine dissolved in water. When iodine and starch are mixed together, they form a bluish-black compound that is easily seen. After soaking in the yellow iodine-water solution for one hour, the cell is once again weighed. You also notice that the solution inside of the cell is now a dark blue color while the solution in the beaker is still a light yellow color from the iodine. What do you expect to happen to the weight of the cell over time and what can you deduce from the color change?

The cell should gain weight over time because it is hypertonic to the beaker environment and water will enter the cell through osmosis. The color change indicates that the iodine molecules were small enough to diffuse across the membrane and react with the starch inside the cell. No color change in the beaker tells us that the starch was too large to cross the membrane from the cell and into the beaker.

Which of the following statements regarding photosynthesis and cellular respiration is FALSE? -The process of photosynthesis does not require the input of energy. -Oxygen is required in cellular respiration to assist in the oxidation of glucose. -Photosynthesis fixes CO2 during the Calvin cycle, whereas cellular respiration releases CO2 during the Krebs cycle. -Photosynthesis is an anabolic process, whereas cellular respiration is a catabolic process.

The process of photosynthesis does not require the input of energy.

You are in lab attempting to prepare a slide of cow blood for observation in a wet mount. You place a small drop of the blood on a slide, add a drop of strong saline (salt) solution, and then cover all of it with a coverslip. After returning to your desk, you observe the slide with your microscope and notice that all of the red blood cells (RBCs) do not look like the nice round donut shaped cells in your lab manual. Instead, the RBCs look very shriveled up. Your lab partner has also made a slide, but the RBCs on their slide do look like the ones in the lab manual; your lab partner used a more dilute solution of saline but the same vial of blood. What is the most plausible explanation for the appearance of the blood cells on your slide?

The saline you used was hypertonic to the RBCs; this resulted in water osmosing through the RBC plasma membrane mostly out of the cell.

Examine the figure below. If each sugar molecule represents a percentage point of sugar dissolved in the solution, what change would you expect to see in the solution level over time and why?

The solution level on the left side of the figure would rise while the solution level on the right side of the figure would decrease. This is because the solution on the left side of the figure is hypertonic while the solution on the right side of the figure is hypotonic.

Examine the following figure. Why did the solution level on the left rise while the solution level on the right decreased? (image with a semipermeable membrane, the right side has higher water and very high sugar molecule concentration. left side has no sugar)

The solution on the left was hypertonic to the solution on the right. Therefore, the water moved by osmosis across the membrane from right to left along the water concentration gradient.

Which of the following statements is true of chloroplasts? They give an animal cell its shape. They capture energy from sunlight. They produce proteins used by other parts of the cell. They contain an entire copy of a cell's genetic material.

They capture energy from sunlight.

Imagine a cell membrane filled with a high concentration of sucrose. Sucrose molecules cannot move across a cell membrane due to their large size. Imagine you've placed this cell into a glass of pure water. Which way will molecules flow?

Water will flow from the glass into the membrane to dilute the sucrose.

Cells contain the molecule GTP (guanosine triphosphate). Would this molecule be useful as an energy carrier (similar to ATP)?

Yes, because it contains the same number of phosphates as does ATP.

________ transport of molecules across a selectively permeable membrane requires the input of energy from the cell whereas ________ transport of molecules across a selectively permeable membrane does not require the use of cellular energy.

active, passive

The G0 phase of the cell cycle is distinguished by

an absence of preparation for DNA synthesis.

In which of the following stages of mitosis would you expect to see chromatids become daughter chromosomes?

anaphase

Cells that demonstrate anchorage independence

are primed to become metastatic.

All of the following contribute to genetic uniqueness EXCEPT

binary fission.

The enzyme rubisco is important to the process of

carbon fixation.

What kind of reaction is shown here? (photo of a chain of colorful warm toned dots, an arrow points down to a group that is not chained) catabolic anabolic photosynthesis respiration

catabolic

A specific gene, called GRAB, prevents a cell from entering mitosis if there are any signs of DNA damage. The cell then kills itself by apoptosis. This means that GRAB would be a type of

cell cycle checkpoint

Sister chromatids are held together at a constriction point called a ________.

centromere

Sister chromatids are held together at a region called the

centromere.

Which of the following processes divides the cytoplasm of cells following mitosis?

cytokinesis

If a cell lacked lysosomes, it would not be able to

digest cellular wastes and bacteria.

The structure highlighted in the figure below corresponds to a (photo of an orange cell with the large, purple chromosome circled) gamete. sister chromatid. kinetochore. duplicated chromosome.

duplicated chromosome.

The energy required for life processes must be extracted from an organism's

environment.

Biological catalysts that can start or speed up a chemical reaction are called:

enzymes

Chemical reactions that occur in the human body are controlled by special catalytic molecules called

enzymes.

Cancers are groups of cells that divide rapidly and uncontrollably. Thus, cancer cells

have a relatively short G1 phase.

During crossing over, replicated chromosomes transition from S phase to G2 phase. neighboring daughter cells fuse together to mix genetic information. homologous chromosomes exchange genetic information. chromosomes leave the nucleus and "cross over" into the cytoplasm.

homologous chromosomes exchange genetic information.

If oxygen is removed from a human muscle cell, the concentration of lactate will _____.

increase

When calcium (Ca++) and chloride (Cl−) interact with one another, they bond using ________ bonds.

ionic

A solid waste (garbage) transfer facility that sorts and breaks down garbage into recyclables and waste to be thrown away in the landfill would be a suitable analogy for which cellular organelle?

lysosome

Which of these structures is primarily responsible for the enzymatic breakdown of large molecules in the cell?

lysosome

An instrument that identifies chemicals based upon their weights is the ________.

mass spectrometer

The form of eukaryotic cell division that produces two genetically identical cells is

mitosis

H2O and CH4 are both examples of

molecules.

The induced-fit model of enzyme activity states that

neither the substrate nor the products can bend to bind with the enzyme; the enzyme must bend to allow interaction.

Which cellular structure is responsible for the localized storage of chromosomal DNA?

nucleus

Oogenesis in humans is unlike spermatogenesis in humans in that

only one functional gamete exists at the end of oogenesis

During cellular respiration, ________ is the step that produces the greatest number of ATP molecules.

oxidative phosphorylation

During cellular respiration, ________ is the step that produces the greatest number of ATP molecules. fermentation glycolysis Krebs cycle oxidative phosphorylation

oxidative phosphorylation

Which of the following solutions has the highest concentration of free H+ ions?

pH 1

An amoeba, a protozoan that moves by pseudopodia, approaches a smaller protozoan and extends its pseudopodia (extensions of cytoplasm in plasma membrane) around the smaller protozoan. Once the amoeba's pseudopodia completely surrounds the other protozoan, the amoeba's plasma membrane pinches off by folding back into the amoeba and creating a vesicle containing the smaller protozoan. This vesicle is now within the amoeba itself and will soon fuse with other vesicles containing digestive enzymes. This is an example of

phagocytosis.

The ________ is a phospholipid bilayer that separates the internal components of a living cell from the cell's external environment.

plasma membrane

Which of the following types of bonds hold hydrogen and oxygen atoms together within an individual water molecule?

polar covalent bond

Macromolecules are typically formed by repetitively adding small monomers together. Which macromolecule is properly matched with the appropriate monomer?

polypeptide-amino acid

The nuclear envelope breaks down during which phase of mitosis?

prophase

Which of the following is the largest in size? protein carbon atom nucleotide glucose

protein

In photosynthesis, the carbon used to make sugars is

provided by carbon dioxide.

The plasma membrane of some white blood cells contain ________ that bind with proteins of cells such as bacteria that have invaded the human body. These special proteins tell the white blood cells those bacterial cells do not belong to that particular human and to phagocytize (eat) them.

receptor proteins

Anabolism usually ________ energy for the reaction to occur to produce polymers, whereas catabolism ________ energy to produce monomers.

requires; produces (low chance this one is wrong)

A(n) ________ allows some substances to move freely into and out of a cell by simple diffusion while it will always exclude some substances from crossing. However, some substances that cannot cross by simple diffusion can pass through with the help of either active or passive transport proteins.

selectively permeable membrane

If a bottle of perfume were spilled in the corner of a large lecture hall, the students sitting near that corner of the room would very quickly smell the perfume. Over time, the students sitting in the far corner of the room would smell the perfume. What phenomenon has occurred to the perfume molecules that have entered the air?

simple diffusion

Photosynthetic organisms capture energy from sunlight and convert it into chemical bonds by forming

sugars.

Chromosomes decondense and nuclear envelopes form during the ________ portion of mitosis.

telophase

Many important cellular functions in eukaryotic cells occur within membrane-enclosed organelles, such as cellular respiration occurring within the mitochondria. The membranes of the mitochondria provide a place for enzymes needed for cellular respiration to anchor and function. Prokaryotic cells must also carry out respiration but do not have mitochondria. Where is the most likely place that enzymes needed for cellular respiration are anchored and functioning?

the plasma membrane

The cell cycle has checkpoints or stopsigns that halt the process of mitosis. Why do checkpoints exist?

to allow the cell to determine if any mistakes have been made, and if there have been mistakes, the cell will kill itself.

Which of the following explains why a cell might undergo meiosis?

to produce egg and sperm cells

Which of the following structures is considered an organelle?

vacuole

Which of the following structures is considered an organelle? vacuole microtubule plasma membrane cytosol

vacuole

Which of the following would be likely to move through a plasma membrane by simple diffusion?

water (H2O), carbon dioxide (CO2), oxygen (O2)

Each time you take a breath you are bringing in the oxygen you need to stay alive. The ultimate source of the oxygen used by all aerobic organisms comes from a reaction that breaks down

water.