BLY 121 Test 2- Chupp

which of the following is NOT responsible for amplifying the signal in a cell responding to adrenaline signaling?

One adrenaline molecule can bind to and activate many receptors simultaneously.

During what stage of cellular respiration are the most ATP molecules produced?

Oxidative Phosphorylation

Which one of the following statements BEST represents the relationship between cellular respiration and photosynthesis?

Photosynthesis stores energy in organic molecules, while respiration releases it

Why do the functions of many receptor kinases depend on the fluid nature of the plasma membrane?

The receptor monomers must move together and dimerize to be activated.

Which one of the following BEST describes why genome sequencing can be complicated by repeated sequences?

The repeated sequences are often longer than the sequences obtained by automated sequencing.

How are oxygen atoms released during photosynthesis?

The splitting of water molecules.

Suppose that three critical amino acids in the active site of a specific enzyme are arginine, lysine, and histidine. Which of the following characteristics would you predict the substrate to possess in order to bind the active site of this enzyme?

hydrophillic, with a negative charge

Epidermolysis bullosa is a set of rare genetic disorders that is caused by:

a keratin gene that disrupts intermediate filaments, weakening epidermal cell connections.

A protein on a cell surface that binds to a signaling molecule is an example of which of the following elements of cellular communication?

a receptor protein

The phosphorylation of glucose during glycolysis serves to: (Select all that apply.)

--trap imported glucose inside the cell -destabilize the molecule, making it easier to cleave

Reducing agent that provides electrons and is thus oxidized during the Calvin Cycle

NADPH

According to the phylogenetic tree showing evolutionary relationships among viruses in Figure 13.6 below, which one of the following is MOST closely related to the human lentivirus HIV2?

a simian lentivirus

Kohler and Lipton first discovered platelet-derived growth factor by observing that fibroblasts:

grew better in cell culture when blood serum was added to the growth medium instead of blood plasma.

ATP is chemically related MOST closely to which of the following?

guanine

Sometimes a single-stranded molecule of RNA is able to fold back on itself because the nucleotide sequence on one part of the RNA is complementary to another part. This sequence motif results in a:

hairpin-shaped structure

Which of the following is a button-like point of attachment formed by the linking of integrins to intermediate filaments inside the cell and their binding to a protein of the extracellular matrix on the outside of the cell?

hemidesmosome

The pH in the stroma of the chloroplast should be ____________ compared with the thylakoid lumen due to the ______________ concentration of protons in the thylakoid lumen.

higher; higher

Which one of the following is NOT found in a bacterial nucleoid?

histones

In large genomes, MOST reciprocal translocations occur in:

noncoding DNA

Cancer-causing genes found in some viruses are called:

oncogenes

The citric acid cycle begins when acetyl-CoA combines with _____ to form _____.

oxaloacetate; citrate

Platelet-derived growth factor (PDGF) is a signaling molecule that functions in which of the following types of cell signaling?

paracrine

In a thylakoid membrane, absorbed light energy is passed from one chlorophyll molecule to another until it is:

passed to a reaction center

In plants, the ultimate electron donor in photosynthesis is:

water

The percentage of 18O2 increases when the:

water in the experiment contains 18O2

Which of the following is NOT found in the extracellular matrix of animal cells?

cellulose

Chromosomal mutations that are MOST likely to cause serious damage to an organism are those that affect the:

centromere

A family can share a genetic risk of developing cancer if:

a germ-line mutation in one of the genes implicated in the cancer occurred in an ancestor.

Which of the following is TRUE about the Delta protein?

-Delta directly signals to a Notch transmembrane protein in adjacent cells. -Delta directs adjacent cells to differentiate into glial cells. -Delta is a transmembrane protein found in embryonic brain cells. -Delta is produced by embryonic stem cells as they differentiate into neurons in the brain.

Which of the following are produced during the Krebs cycle?

-NADH -FADH2 -ATP

During what stage(s) of cellular respiration is carbon dioxide produced?

-Pyruvate oxidation -Krebs cycle

How does the extracellular matrix affect a cell that it surrounds? (Select all that apply.)

-The genes that the cell expresses depend in part on the types of proteins in the extracellular matrix. -The cell's shape depends in part on the structure and composition of the extracellular matrix.

Which of the following steps in prokaryotic binary fission is CORRECT?

-The two replicated chromosomes remain attached to the plasma membrane. -Cell wall material is laid down at the midpoint to separate the two daughter cells -DNA is replicated bidirectionally from a single point on the circular chromosome. -The cell continues to grow outward symmetrically, separating the two chromosomes.

A cell's particular shape is largely determined by:

-cytosolic proteins that assemble into structures called cell junctions. -a mesh of proteins and polysaccharides in the extracellular matrix. -cytoskeletal protein networks in the cytoplasm.

Polyploidy, which is widespread among plants, can arise from which of the following processes? (Select all that apply.)

-duplication of a complete set of chromosomes in a single species -hybridization between related species followed by duplication

Which of the following is a product of the breakdown of lipids? (Select all that apply.)

-glycerol -acetyl-CoA -NADH -FADH2

What happens in the Calvin cycle of photosynthesis?

-hydrolysis of ATP to ADP -the incorporation of CO2 into an organic molecule by RUBISCO -the synthesis of a three-carbon carbohydrate

Sexual reproduction results:

-in a new generation that is not genetically identical to its parents. -in offspring that are not genetically identical. -from combining genetic material from two gametes -in a new generation with the same number of chromosomes as each parent.

Microtubules increase in length:

-in cycles, following rapid depolymerization. -by growing outward from the centrosome. -more quickly at one end than the other. -if free tubulin dimers are available.

Essential elements for communication:

-signaling cell -signaling molecule -receptor molecule -receptor cell

Studies of rapidly dividing embryonic animal cells revealed:

-that the production of cyclin proteins is followed by activation of CDK enzymes. -a cyclic activation of protein kinases in sync with the cell cycle. -that inhibition of protein production blocks mitosis. -a cyclic production of certain proteins in sync with the cell cycle.

Core concepts:

1. Cells can communicate over long and short distances. 2. signaling molecules bind to and activate cell-surface and intracellular receptors 3. G protein-coupled receptors are a large, conserved family of receptors that often lead to short-term responses 4. Receptor kinases are widespread and often lead to long-term responses

Signaling between cells involves 4 steps:

1. receptor activation 2.

In living organisms, on average, about one nucleotide in every _____ is mistakenly substituted for another during each round of DNA replication.

10 billion

According to Figure 14.2, the average number of new mutations that occur across an entire human genome in one generation is approximately _____ times higher than in nematodes.

100

How many reactions in glycolysis directly generate ATP?

2

Approximately what percentage of the human genome actually codes for proteins?

2.5%

How many pairs of chromosomes does the human genome normally have?

23

A photosynthetic electron-transport chain captures in chemical form approximately what percentage of the sun's usable energy arriving at the surface of a leaf?

24%

How many CO2 molecules must enter the Calvin cycle for each molecule of triose phosphate that can be exported from the chloroplast?

3

Approximately what percentage of the sun's output is available for photosynthesis?

40%

The human genome has 23 distinct types of chromosomes. How many individual DNA molecules would be present in the nucleus of a human skin cell just before mitosis?

92

Certain complexes of the mitochondrial electron transport chain pump protons. Which of the following BEST describes the movement of protons in this situation?

A. across the inner mitochondrial membrane, from the matrix to the intermembrane space

Which of the following statements is NOT one of the laws of thermodynamics?

All cells arise from pre-existing cells.

In what way is cytokinesis in plant cells similar to binary fission in a bacterium?

Cell wall material is deposited to separate the daughter cells.

what is a key difference between cell signaling by a cell-surface receptor and cell signaling by an intracellular receptor?

Cell-surface receptors bind polar signaling molecules; intracellular receptors bind nonpolar signaling molecules.

The enzyme _____ repairs 99% of mismatched bases immediately during replication.

DNA polymerase

The energy carried by photons is:

Electromagnetic energy

Which one of the following is a candidate for the FIRST electron donor?

Fe2+

What stage(s) of cellular respiration DO NOT occur in the mitochondria?

Glycolysis

Which of the following is NOT true about the eukaryotic cell cycle?

Interphase is typically the shortest of the two stages of the cell cycle.

Which of the following statements is TRUE if a cell has a mutation in the p53 gene such that the p53 protein is no longer able to be phosphorylated?

The cell would proceed through the cell cycle even in the presence of DNA damage.

Sequences of genomic DNA, and its corresponding messenger RNA (mRNA), are often compared to obtain valuable information for genome annotation. Why is this comparison useful?

The exclusion of introns in mRNA reveals the intron-exon structure of many protein coding genes.

Which of the following statements is NOT true about gamete formation in mammals?

The polar bodies formed during meiosis in the female can participate in fertilization with sperm.

Which of the following describes catabolic reactions?

They are exergonic and have a negative change in free energy.

which one of the following is an example of potential energy?

an electrochemical gradient

Animals breathe in air containing oxygen and breathe out air containing less oxygen. The consumed oxygen is used:

as an electron acceptor in the electron transport chain of cell respiration

In which form are electrons transferred during typical redox reactions such as the oxidation of glucose?

as hydrogen atoms

According to Figure 13.8 below, which one of the following accurately lists the taxonomic groups in order of INCREASING genome size (i.e., from smallest to largest)?

bacteria, teleosts, mammals, salamanders

Which is NOT a stage of cellular respiration?

calvin cycle

Which one of the following is NOT a product when photosystem II oxidizes a molecule of water?

carbon dioxide

Insertions and deletions of single nucleotides:

cause frameshift mutations

Animals such as cats, worms, and butterflies are classified as:

chemoheterotrophs

Which one of the following does NOT actively move protons from the mitochondrial matrix to the intermembrane space?

complex II

The amount of _____ is fairly constant throughout the cell cycle, but the amount of _____ varies.

cyclin-dependent kinase/DNA

Some bacteria generate ATP through glycolysis alone. This indicates that the environment they live in is____________.

depleted of oxygen

PFK-1 is ______ by ATP and __________ by ADP.

inhibited; activated

ATP is a good energy currency for cells because it has a(n) _____ amount of Gibbs free energy.

intermediate

Which of the following provide structural support for epithelial cells, such as those in the skin (keratinocytes)?

intermediate filaments

Zebrafish embryos change the color of the melanophore cells in their skin to a darker shade by:

kinesin motor proteins moving pigment granules outward from the center of the cell.

In human cells such as muscle tissue, the product of fermentation is:

lactic acid

Which type of receptor is involved in rapid responses of muscle cells and neurons?

ligand-gated ion channel

Which of the following enable(s) the movement of cells?

microtubules and microfilaments

n the chloroplast, cytochrome b6f is an important complex in the photosynthetic electron transport chain because it accepts electrons from photosystem II and donates them to photosystem I. Another vital function of cytochrome b6f is that, during its reduction-oxidation cycle, it moves _____ from the _____.

protons; stroma into the thylakoid lumen

phosphate groups play a key role in receptor kinase activation by:

providing binding sites to recruit and activate signal-transduction proteins.

Which of the following has the MOST similarity in nucleotide sequence?

sister chromatids

Reactions in which there is a negative change in free energy (-ΔG) are:

spontaneous and exergonic

In eukaryotic cells, the oxidation of pyruvate occurs in:

the matrix or the mitochondria

Reciprocal translocations can affect gene dosage because:

the two chromosomes involved in the translocation may not assort together during meiosis.

ATP synthases in the thylakoid membrane are powered by the flow of protons from the:

thylakoid lumen to the stroma

light energy is converted to chemical energy in the:

thylakoid membrane

Which of the following is a mesh-like attachment between cells formed by binding of transmembrane proteins of one cell to the same protein type on the adjacent cell, preventing substances from passing between cells?

tight junction

What is the function of an enzyme?

to both increase the rate of a specific reaction and decrease the amount of energy needed to reach the transition state