Mcgraw hill biology final

Which level of organization is present in all life forms?

cells

true or false: vertical evolution is the only mechanism of evolution on earth?

false

The human species is called “Homo sapiens” . the first word refers to which taxonomical grouping?

genus

which domain of life contains the most multicellular organisms?

Eukarya

A wristwatch suddenly stops working. After replacing the battery, the watch starts working again. Which of the following statements correctly describes the situation from the perspective of the scientific method?

This is consistent with the hypothesis that a dead battery caused the wristwatch to stop working.

When one atom loses an electron to another atom, it results in the formation of

a cation and an anion that can form an ionic bond.

For water ti vaporize

both energy must be supplied and hydrogen bonds broken

The double arrow in this reaction indicates that it is

CH4 + 2 O2 ↔ CO2 + 2 H2O

in equilibrium

The molecule that is polar and acts like a base is

R−NH2

When placed in an aqueous solution, amphipathic molecules will orient themselves with

hydrophobic hydrocarbon chains in the middle and hydrophilic head groups facing the water.

The major class of macromolecules that stores energy and is the main constituent of plasma membranes is

lipids

The macromolecule composed of amino acids is a

proteins

The sequence of amino acids in a protein is its _________blank structure.

primary

The most accurate nucleotide base composition of the DNA double helix is

T+G=A+C

What is the key structural difference between DNA and RNA?

DNA contains the sugar deoxyribose, whereas RNA contains the sugar ribose. 

Cell theory or cell doctrine is based on some basic principles. Choose the description that best addresses these principles.

All living organisms are composed of one or more cells, cells are the smallest units of life, and new cells come only from pre-existing cells by cell division.

To observe the three-dimensional structure of a cell the best type of microscopy would be

scanning electron microscopy.

Eukaryotes such as animal and plants cells differ from prokaryotes in that prokaryotes

lack of internal compartmentalization

plasma membranes are a feature of

all cells

The organelle responsible for the biosynthesis of proteins that are destined for secretion by the cell is the

endoplasmic reticulum

Which of the following organelles are most likely to be able to divide and reproduce similar to that of a cell?

mitochondria and chloroplasts

Which of the following organelles are most likely to be able to divide and reproduce similar to that of a cell?

amyloplasts

Materials move in and out of the nucleus via endocytosis and exocytosis.

false

What is the major lipid found in membranes?

phospholipids

Which component of the cell membrane might contribute to maintaining the fluidity of plasma membranes under freezing conditions?

high levels of unsaturated phospholipid tails within the lipid bilayer

If a cell suddenly loses the ability to activate fatty acids by the attachment of a CoA molecule, what will be the most significant impact on the cell membrane?

phospholipids will no longer be synthesized in the ER

What are the two major components of cell membranes?

phospholipids and proteins

ture or false: simple diffusion is a spontaneous process

true

The movement of sucrose and H+ into the cell by the same membrane protein reflects the actions of what type of transporter?

symporter

What process best characterizes  Ca2+ movement from the cytosol (low Ca2+ concentration) into the endoplasmic reticulum (high Ca2+ concentration)?

Calcium movement involves active transport.

In ALL exergonic reactions,

the reaction proceeds with a net release of free energy.

How does an enzyme work to catalyze a reaction?

It lowers the activation energy of a reaction.

Noncompetitive inhibitors bind the active site of an enzyme, reducing its activity and the subsequent formation of product

false

noncompetitive inhibitors bind to

allosteric site

The equation, C6H12O6 + 6O2 → 6CO2 + 6H2O  (ATP + Heat), describes which of the following processes?

cell respiration

where does the citric acid cycle occur?

mitocondria matrix

How is a gradient of H+ ions formed across the inner mitochondrial membrane?

The electron transport chain uses energy from transfer of an electron donated by NADH to pump H+  across the inner mitochondrial membrane against its electrochemical gradient.

Sports physiologists at an Olympic training center want to monitor athletes to determine at what point their muscles were functioning anaerobically. They could do this by checking for the buildup of which molecule?

lactate

true or false:

cellular respiration, a  H+ electrochemical gradient is formed so that the H+  concentration is lower in the intermembrane space than inside the matrix.

false

where is the electrochemical gradient formed during cell respiration

where the hydrogen concentration is higher in the intermembrane space

In the structure of ATP synthase, where do H+ ions cross the mitochondrial membrane?

between the transmembrane a and c subunits

When a cell releases a growth factor that binds to receptors on neighboring cells causing them to proliferate, this is an example of

paracrine signaling

When a cell makes a cell membrane bound growth factor that binds to receptors on neighboring cells causing them to proliferate, this is an example of

contact-dependent signaling

When a cell secretes a growth factor that binds to receptors on its own membrane preventing it from proliferating, this is an example of

autocrine signaling

When insulin is secreted from the pancreas and acts on muscle cells to increase glucose uptake, this is an example of

endocrine signaling

When sodium ions move from one cardiac muscle cell to an adjacent cell, causing them to contract in unison, this is an example of

direct intercellular signaling

When epidermal growth factor binds to its _________blank, the receptor phosphorylates itself, triggering a signal transduction pathway.

enzyme-linked receptor

What happens next after the hormone glucagon binds to a G-protein coupled receptor (GPCR)?

The G-protein loses GDP and gains GTP becoming activated.

When a neurotransmitter released from one neuron binds to a _________blank on a second neuron, that neuron depolarizes and fires.

ligand-gated ion channel

true or false: Apoptosis is used in humans in order to eliminate cells infected by viruses, cells that are worn out, and those that have the potential to cause cancer.

true

true or false: The extracellular matrix provide an important source of energy for the organism

false

If a plant cell is stripped of its cell wall it forms a protoplast. A protoplast would

be less rigid than a plant cell.

The protective layer external to the plasma membrane of the plant cell is called

cell wall

These act as rivets anchoring adjacent cells together at spots throughout the cell.

desmosomes

Gap junctions in animal cells are most similar to _________blank in plant cells.

plasmodesmata

If you wanted to separate cells of a plant tissue sample into individual cells you would need to disrupt

middle lamella

Which of the following relationships about nucleotide composition in DNA is TRUE?

C+A=G+T

the mechanisms of DNA replication is

semiconservative

If the sequence for one strand of DNA is 3′-TCGATT-5′ then its complementary strand would have a sequence of 3′-AGCTAA-5′.

false

If the sequence for one strand of DNA is 3′-TCGATT-5′ then its complementary strand would be

5′-AGCTAA-3′

is replication fork involved in DNA replication?

no

what are the proteins involved in DNA replication`

DNA ligase, single stranded binding proteins, topoisomerase, helicase

DNA polymerase functiuon

It is an enzyme that catalyzes the addition of nucleotides to the 3′ end of a growing DNA strand.

Why is there a need to produce Okazaki fragments on the lagging strand, but not on the leading strand of DNA?

The two parental strands of DNA are antiparallel and DNA polymerase makes DNA in the 5′ to 3′ direction only.

The process that produces mRNA from DNA is called

transcription

The processes of transcription and translation are collectively known as

gene expression

An organized unit of DNA sequences that enables a segment of DNA to be transcribed into RNA and ultimately results in the formation of a functional product is called a _________

gene

true or false: RNA polymerase II of eukaryotes always requires more than one general transcription factor to initiate transcription.

true

Which of the following statements about the 5′cap and mRNA processing is TRUE?

The addition of a 5′ cap to mRNA occurs while the pre-mRNA is being made

What is the function of the poly A tail?

increases mRNA stability in eukaryotes.

What is apart of translation machinery?

mRNA, tRNA, translation factors, and ribosomes

If part of a DNA template strand is the sequence GTTAGTCTGTGGGCT. The mRNA transcribed from it is

CAAUCAGACACCCGA

A cells ability to control its level of gene expression is called

gene regulation

What type of regulatory transcription factor binds DNA and increases the transcription of a gene?

an activator exerting positive control

A(n) _________operon is one whose transcription is decreased by effector molecules.

repressible

Whats the function of DNA methlation

inhibits transcription

Lac permease in bacteria is a membrane protein required to transport lactose into the cytoplasm of bacteria. It is encoded by the lacY gene. Certain lacY mutations render the protein completely unable to transport lactose. In these mutants, what will be the transcriptional state of the lac operon?

The lac operon will be repressed regardless of glucose levels.

Sequence the following events of mitosis.

1. Sister chromatids align on the metaphase plate.

2. The cleavage furrow forms.

3. The nuclear membrane breaks up.

4. Sister chromatids condense.

5. Sister chromatids separate.

IV, III, I, V, II

true or false: During prometaphase, the sister chromatids organize into a single row in the center of the cell.

false

true or false Homologous chromosomes are identical copies of each other.

false

During crossing over in meiosis, an unequal exchange of genetic material occurs. This would most likely produce

a deficiency in one homolog and duplication in the other homolog

Meiosis I produces _________blank, and meiosis II produces _________blank cells.

2 haploid, 4 haploid

true or false:One major difference between metaphase I and metaphase II is the presence or absence of bivalents.

true

The formation of the bivalent during meiosis

contributes to the genetic diversity of a species.

The process by which haploid cells are produced from diploid cells is called

meiosis

true or false: During meiosis, homologs are identical, which provides a mechanism for increasing genetic diversity among gametes.

false

The probability of obtaining a dominant phenotype from self-fertilization of a heterozygous individual is

75%

true or false: The law of independent assortment states that the two alleles of the same gene will segregate from each other during gamete formation.

false

A homologous pair of mitotic chromosomes will possess _________blank alleles for each locus

four

What feature of meiosis allows for independent assortment of chromosomes?

random alignment of homologous chromosome pairs on the metaphase plate

incomplete dominance is when

the phenotype of a heterozygote is not the same as either parent, but it is somewhere between the two parents.

in codominance

the heterozygote exhibits the phenotypes of both parents equally

The amino acid serine reacts with indole to make tryptophan in the final step of the tryptophan biosynthesis pathway in bacteria. In a bacterial cell that has become unable to produce or import serine, what would occur at the trp operon?

The trp repressor would be unable to bind to the operator and the trp operon would be transcribed.

When sodium ions move from one cardiac muscle cell to an adjacent cell, causing them to contract in unison, this is an example of

direct intercellular signaling

When epidermal growth factor binds to its _________blank, the receptor phosphorylates itself, triggering a signal transduction pathway.

enzyme-linked receptor