Biology Exam 2

Epigenetics is translated as

"above the genome"

Based on the gel run in lab and lab discussion, a person with MSUD will have how many bands for this gene?

1

Place the steps of DNA transcription in the order in which they occur.

1. The RNA polymerase attaches to the DNA strand upstream from a gene 2. RNA bases are paired with the DNA bases on the template strand by RNA polymerase 3. The RNA breaks away from the RNA polymerase, and they both leave the DNA strand

Based on the gel run in lab and lab discussion, a person without MSUD (and not a carrier) will have how many bands for this gene?

2

Mitosis end result

2 identical cells, diploid cells

Only ___________ different amino acids can form ___________ proteins.

20...thousands

Human somatic cells contain 46 total chromosomes. How many chromosomes would a human sperm cell contain?

23 total

Emma and Jacob are both heterozygous for MSUD. What art the chances that their next child will have MSUD?

25%

Based on the gel run in lab and lab discussion, a person heterozygous for MSUD will have how many bands for this gene?

3

Meiosis end result

4 different cells, haploid cells

How many chromosomes are present in your somatic cells?

46

Communication Protein

A membrane receptor protein binds to a signaling molecule sent from a neighboring cell

Recognition Protein

A pair of liver cells identity one another using cadherin membrane proteins

A restriction enzyme acts like a

A pair of scissors

Structural Protein

A peripheral membrane protein attaches to the network of proteins surrounding the cell

What happens during the initiation step of DNA transcription?

A portion of the DNA unwinds and RNA polymerase attaches to the DNA within the transcription bubble.

Transport Protein

A potassium pump protein uses ATP to move ions across the plasma membrane against their concentration gradient

After an mRNA strand has been transcribed from DNA, it must be processed before translation can take place. Which of the following statements are true about the RNA editing process?

A tail is added to one end of the mRNA molecule and Introns are removed and coding segments are joined.

Passive Transport does not require?

ATP

Which mRNA codon functions as the start codon, directing the ribosome to begin translating the mRNA from the correct end?

AUG

The inheritance pattern for sheep coat color exhibits incomplete dominance. A sheep that is homozygous for the black allele is crossed with a sheep that is homozygous for the white allele. What is the phenotypic outcome of the offspring that result from this cross?

All offspring have gray coats.

Identify the statement that defines an individual who is heterozyous for a gene.

An individual inherits two different alleles for a gene.

Identify the statement that describes an individual who is homozygous for a gene.

An individual inherits two of the same alleles for a gene.

Where in the cell does translation occur?

At the ribosome

In certain breeds of chickens, black feathers (CB ) are codominant with white feathers (CW ). What is the genotype of a chicken of this breed with black feathers?

CBCB

Move easily through the lipid bilayer of the plasma membrane

Carbon Dioxide

A good analogy for the genome and the epigenome is

Computer hardware and software

The promoter is found on?

DNA

Which of the following is NOT directly involved in translation?

DNA

Gene?

Determines a particular characteristic of an organism, codes for a specific protein or RNA, acts as the basic unit of heredity

Which of the following best describes you (as an adult)?

Diploid, multicellular adult

Gene regulation that takes place as the DNA is uncoiled and loosened from the nucleosome to allow the binding of transcription factors is best called

Epigenetic level

Both strands of a DNA double helix are transcribed. True or False

False

Each cell of your body has only the genes needed for the proteins needed by that cell. True or False

False

In a gel, small DNA fragments move toward the positive electrode and large fragments move toward the negative electrode.

False

The cap and tail are added to the spliced RNA in the cytoplasm of the cell.True or False

False

There are alternative ways to splice the introns during RNA processing in the nucleus. True or False

False

How did researchers treat pregnant mice to make sure the offspring would be brown and thin (as opposed to yellow and obese)?

Fed them food with methyl groups

Red-green color blindness is a recessive, X-linked trait. Which statements describe the differences between how the trait for color blindness is expressed in males and females?

Females with one recessive allele and one dominant allele will not express the trait and Males are more likely to express the trait than females.

You inherit your ______________________ but you can alter your __________________________."

Genome...epigenome

What happens during anaphase I of meiosis?

Homologous chromosomes separate but sister chromatids remain joined at their centromeres.

Lily, a student in an introductory biology class, learns that some alleles, such as blood type alleles IA and IB, are codominant with one another. She also learns that blood type allele i is recessive to the IA and IB alleles. Lily knows that her mother has blood type AB and her father has blood type A, but she does not know her own blood type. Identify all the possible genotypes for blood type that Lily may have.

IAi, IBi, IAIB, IAIA

Chromosome?

It is a contiguous piece of DNA, is a unit of DNA carrying genetic information encoded in genes, functions to package, organize, regulate access to DNA, is the largest molecule in cell, is a linear or circular molecule

Identify why this codon functions as a stop codon.

It is formed by a mutation and has no corresponding mRNA anticodon.

How are DNA fragments separated using gel electrophoresis?

Larger DNA fragments move more slowly through the gel than do smaller fragments.

In which organism did the researchers study the agouti gene?

Mouse

contains DNA in the cell

Nucleus

Gene regulation that takes place when the RNA is processed and exported to the cytoplasm is best called

Post-transcriptional level

Gene regulation that takes place after the RNA is translated into the polypeptide chain in the cytoplasm is best called

Post-translational level

During transcription what enzyme adds new nucleotides?

RNA polymerase

Which enzyme is responsible for linking nucleotides together to make mRNA?

RNA polymerase

protein complex that makes RNA polymers corresponding to a DNA template

RNA polymerase

What happens during the elongation step of DNA transcription?

RNA polymerase moves along the template strand of the DNA creating an mRNA strand.

What is a likely evolutionary advantage of sexual reproduction over asexual reproduction?

Sexual reproduction results in greater variation in the offspring

What happens during anaphase II of meiosis?

Sister chromatids separate from each other and migrate to opposite ends of the cell.

How could one identical twin have cancer and the other doesn't?

Some genes are turned off in one of the twins.

Which of the following are properties of protein-facilitated active transport?

Substances move from an area of lower concentration to an area of higher concentration and Substances cross the plasma membrane by being pumped through a protein using ATP.

The process of meiosis is responsible for creating much of the genetic variation seen in sexually reproducing organisms. Which events in the process of meiosis generate this genetic variability?

The arms of adjacent chromatids cross over and switch places with each other in prophase I and A homologous pair lines up along the metaphase plate independently of the other pairs.

What happens during the termination step of DNA transcription?

The mRNA detaches from the RNA polymerase as the RNA polymerase leaves the DNA strand.

Which choice describes diffusion?

The movement of a substance from a region where it is more concentrated to a region where it is less concentrated down its concentration gradient.

What occurs during the heating cycle of PCR?

The two strands of DNA are separated

Which statement describes the central dogma of biology?

Transcription is the process of synthesizing RNA from DNA. Translation is the process of synthesizing an amino acid sequence from RNA.

Gene regulation that takes place as the RNA is transcribed in the nucleus is best called

Transcriptional level

All cells in a person have the same genes.

True

All the skin cells on your finger have the genetic information needed to make the proteins produced by liver cells. True or False

True

Biotechnology applications include medicine, agriculture, industrial and household applications. True or False?

True

Identical twins have the same nucleotide sequence in their DNA. True or False

True

Prior to both mitosis and meiosis, chromosomes are duplicated. True or False

True

RNA is single-stranded while DNA is double-stranded- True or False

True

Which RNA nucleotide will pair with an adenine on the DNA molecule?

Uracil

Which of the following is unique to RNA?

Urcail

How do we study epigenetics in humans?

Use identical twins

What is a peptide bond?

a covalent bond formed when the carboxyl group of one molecule reacts with an amino group of a different molecule

Which statement describes a gene?

a section of DNA in which the code for a protein is located

Which of the following is the definition of a sex-linked trait?

a trait that is coded by a gene located on a sex chromosome

Which of the following requires energy (ATP) to be expended?

active transport

Which of the following will be used to move material into a cell against the concentration gradient?

active transport

The F1 generation of a cross TT x tt will be

all Tt

What are the monomers, or building blocks, of a protein?

amino acids

Translation?

amino acids added to peptide chain, requires tRNA, happens in ribosome, builds protein

Which of the following defines an individual that is true-breeding for a particular trait?

an individual that is homozygous for the gene that encodes the trait

Which statement describes dominant alleles?

any allele that can hide the presence of a different allele

What happens during replication?

both DNA strands are duplicated, described as semi-conservative, DNA polymerase

A methyl group is composed of which two elements?

carbon and hydrogen

contains a carbohydrate chain that allows the body to recognize its own cells

cell recognition protein

Which of the following are common to all 20 amino acids?

central carbon, amino acids, R group, carboxyl group

contains a passage that spans the entire membrane and permits only specific molecules to diffuse across

channel protein

Another word for shriveled cell is ____________________.

crenated

Which of the following will most likely occur when red blood cells are placed in a hypertonic solution?

crenation - because there is a net movement of water out of the cells

Your body cells are ____________, which mean they have two of each "kind" of chromosome.

diploid

Each cell that enters meiosis is ________, which can be designated as ___.

diploid...2n

A salt concentration of .9% salt is isotonic to red blood cells. Which of the following solutions would be hypotonic to red blood cells?

distilled water

How many DNA molecules would you have after 3 cycles of PCR?

eight

participates in chemical reactions involved with metabolism

enzymatic protein

Which portions of the transcribed RNA will become the mRNA that undergoes translation in the cytoplasm?

exons only

A Glucose molecule would move across a plasma membrane by which process?

facilitated diffusion

An individual has the genotype XX and has 45 autosomes, including 3 copies of chromosome 21. This person will be ________ and the condition is known as ___________.

female...Down syndrome

An individual has the genotype XO. This person will be ________ and the condition is known as ___________.

female...Turner syndrome

Tertiary

form three-dimensional shape

Once a length of DNA is cut into pieces, the pieces can be separated using

gel electrophoresis

A methyl group attaches to _________________ and turns them_________________.

genes, off

What type of protein is present in red blood cells to transport oxygen?

hemoglobin

Consider pea plants with purple/white flower color. Purple color is dominant to white flower color. A pea plant with purple flowers but unknown genotype is crossed with a pea plant with white flowers. The offspring show 14 plant with white flowers and 10 plants with purple flowers. What is the genotype of the parent pea plant with purple flowers?

heterozygous

Chromosome #7 from your dad and chromosome #7 from your mom are _______________________ chromosomes.

homologous

Meiosis 1

homologous chromosomes fail to separate, result in 4 abnormal cells

A recessive trait is observed in individuals that are __________ for that trait.

homozygous only

Biological membranes are present in all cells, and they make up the endomembrane system of eukaryotic cells. They have many functions, including acting as barriers that selectively allow the transport of small molecules and ions into and out of the cell or organelle. A biological membrane is a bilayer that contains lipids with

hydrophilic head groups oriented toward the solvent (extracellular fluid and cytosol) and hydrophobic tail groups pointing inward.

The head of a phospholipid bilayer is what?

hydrophilic, phosphate rich

How are biological membranes held together?

hydrophobic interactions

A solution with a higher solute concentration is ______________________ to a solution with a lower solute concentration.

hypertonic

Water intoxication (or excess consumption of water) can lead to swelling of the brain (or cerebral edema). For the brain to swell, what type of solution is the brain placed into?

hypotonic

Consider the dialysis tubing used in lab. The dialysis tubing is ____________ to chloride ions and __________ to water.

impermeable...permeable

Where in the cell does transcription occur?

in the nucleus

An anticodon is a sequence of three nucleotides that

is found on transfer RNA and is complementary to messenger RNA codons.

connects cells together and facilitates communication between them

junction protein

DNA fragments will move slower in a gel if the fragments are

large

Which of the following are components of biological membranes? Select all that apply.

lipids and proteins

An individual has the genotype XXY. This person will be ________ and the condition is known as ___________.

male...Klinefelter syndrome

Genome?

may include plasmids, describes the collection of all of the replicable genetic material of a cell or organism, each organism has one, encodes all the heritable traits of an organism

The phosphate groups of nucleotides have a net _______ charge.

negative

The tail of a phospholipid bilayer is what?

non-polar, does not mix with water, fatty acid chains

Many errors can occur during meiosis. Which term describes the process of sister chromatids not separating at the centromere during cell division?

nondisjunction

Which statement describes an allele?

one variation of the code for a protein

Which of the following is required to include in your PCR tube?

orginial DNA, free nucleotides, Taq polymerase, primers

Which of the following would move across a plasma membrane via simple diffusion?

oxygen gas

An individual who is heterozygous for a trait has a

pair of nonidentical alleles

The order and sequence of amino acids is the ______________ structure of protein.

primary

region of DNA that recruits the transcriptional machinery

promoter

A restriction enzyme is a type of

protein

Quaternary

protein subunits forming a complex structure

Epigenetic therapy in treating MDS leukemia, a cancer of the blood and bone marrow, include which of the following?

reactivating genes

recognizes and binds to signal molecules, leading to a reaction within the cell

receptor protein

Select the phrases that describe the plasma membrane.

regulates transport of molecules into and out of the cell, creates a barrier between the inside and outside of the cell

site of protein synthesis

ribosome

Primary Structure

shapeless strand of amino acids

Transcription?

single DNA strand is used to produce mRNA, happens in nucleus

Meiosis 2

sister chromatids do not separate at the centromere, result in 2 abnormal cells

Need help from a protein to cross the membrane because they are repelled by the lipid bilayer

sodium chloride, calcium ions, amino acids, glucose

Based on information in your lab exercise, Activity 4, what type of mutation is responsible for MSUD?

substitution

provides amino acids to growing protein chain

tRNA

Suppose Jennifer has a PCR product that contains three DNA fragments of 500, 800, and 900 base pairs in length. She separates the three fragments using gel electrophoresis. Which fragment will migrate the farthest from the wells at the top of the gel?

the 500 bp fragment

Genotype

the allele combinations an organism has, Rr

Crossing-over is

the exchange of non-sister chromatid segments.

A test cross is used to determine

the genotype of an individual

Plasma membranes are selectively permeable (semipermeable), meaning that

the membrane permits the transport of only certain substances.

Which statement describes a genotype?

the pair of DNA sequences an organism has for a trait

Phenotype

the physical expression of a gene, baldness

Which statement describes a phenotype?

the physical trait produced by an organism's genetic makeup

Gel electrophoresis is used to separate DNA on the basis of size and charge. DNA will move toward ___________electrode.

the positive

Select the description of RNA splicing.

the process by which noncoding regions are cut out of pre-mRNA and coding regions are joined together to form mature mRNA

may use energy to move substances across a membrane

transport protein

Which of the following type of activity is defective in a person with cystic fibrosis?

transporting ions across a membrane

In the obese and yellow mice, the agouti gene is

turned on all the time

Secondary Structure

twisted into alpha helices and pleated sheets, only formed by some proteins

Allele

variation of a gene, R or r

Osmosis is the diffusion of _____________.

water