bio exam 3

DNA replication in order:

1. unwinding the DNA double helix 2. complementary base pairing 3. joining nucleotides to the growing DNA strand

What is the probability that 2 heterozygous individuals will producce a child that is recessive?

1/4

What is the expected phenotypic ratio of a Mendelian dihybrid cross if both parents are heterozygous for both traits?

9;3;3;1

WHat are some traits that are classified as having polygenic inheritence patterns?

diabetes human height skin color

Independant assortment states that alleles that are inherited independently must be located on _______________ chromosomes.

different

Gene ____________ refers to the production and usage of a gene's product.

expression

What is an example of incomplete dominance?

familial hypercholerserolemia

IN mammals the individuals with the XX chromosomes are ___________ and the individuals with XY are ___________.

females; males

There are _________ different types of DNA nucleotides.

four

Dominant alleles have a DNA equence that produces a _____________ _______________ protein.

fully functioning

Examples of x-linked recessive disorders:

hemophilia color-blindness muscular dystrophy adrenoleukodystrophy menkes syndrome

During after eukaryotic transcription, _____________ molecules are processed.

mRNA

The type of nucleic acid bearing codons for the amino acid sequence is called _________.

mRNA

A growth that is cancerous and has the ability to spread, is referred to as ________________ tumor.

malignant

What units play a role in translation initiation?

messenger RNA Initiator tRNA small ribosomal subunit large ribosomal subunit

During which phase of mitosis are animal cell chromosomes the same distance from both spindle poles?

metaphase

The process by which a cancer travels through the blood and invades new tissues is called ________________.

metastasis

Which parent will pass a recessive X-linked allele to their sons?

mother

Mendel developed the _______________ theory of inheritence, which was based on the exsistence of hereditary units that we now call __________.

particulate; genes

The chart that shows the pattern of inheritance from one generation to the next is known as a ____________________.

pedigree.

At the end of cell division, the cell __________ is the new plasma membrane in a plant cell that marks the location for new cell walls.

plate

What produces the most protein product?

polyribosomes translating an mRNA transcript

Taking pre-mRNA and changing it to a final mRNA transcript requires multiple steps of RNA ________________, like removal of introns.

processing

During which phase of mitosis do spindle fibers attach to kinetochores?

prometaphase

To initiate transcrition, RNA polymerase binds to the _____________ region of the gene.

promoter

WHich type of biomolecule are growth factors made from?

proteins

___________ is the study of the set of proteins that an organism produces.

proteomics

The normal genes that speed up the cell cycle are called _____ ________________.

proto-oncogenes

The body cells (those that do NOT undergo meiosis to become sperm and egg) are called ______________ cells.

somatic

The process of _____________ uses mRNA, tRNA, and ribosomes to synthesize proteins.

translation

The genetic code is said to be a ____________ code, because a set of three nucleotide bases codes for a particular amino acid.

triplet

The presence of only one of which of these alleles is what makes human maes hemizygous for x-linked traits?

x allele

WHat characterizes DNA replication in eukaryotes?

-involves linear chromosomes -creates replication bubbles -has numerous origins of replication

What are similarities between prokaryotic and eukaryotic DNA replication?

- both are semiconservative - both happen from the 5' to 3' direction - both involve DNA polymerase - both result in 2 copies from one parent molecule

What were the contributions of the work of James Watson and Francis Crick?

-Determined that nucleotides were paired inside the double helix - discovered the double helix shape of deoxyribonucleic acid - Determined the sugars and phosphates formed backbones in the DNA

Which of the following occurs during G1?

-accumulation of materials for DNA synthesis - increasing number of organelles - increasing in size

What are similarities between DNA polymerase and RNA polymerase?

-both add nucleotides to the 3' end of the new strand - both are types of proteins

A cell in metaphase would have which of the following characteristics?

-chromosomes aligned along the cell equator - spindle fibers attached to kinetochores - duplicated chromosomes - sister chromatids present

Premises of Mendel's Law of Segregation:

-individuals have 2 factors for each trait -the factors separate during gamete formation - gametes contain only one of the two parental factors - random fusion of all possible gametes occurs upon fertilization, providing gamete two copies of each factor

What are the post-transcriptional modifications of mRNA?

-introns are taken out -addition of a 5' cap -addition of poly-A tail

RNA polymerase has all the following in common with DNA polymerase:

-nucleotides are added to the 3' end - a growing strand runs in a 5' to 3' direction - nucleotides are joined together

Indicate the role(s) of tumor suppressor genes:

-promote apoptosis - inhibit the cell cycle

What happens during the termination phase of translation?

-protein product is released - release factors binds to stop codon - ribosomal subunits dissociate

WHy must the genetic material be a stbale molecule?

-so replication can be accurate -so genetic material can pass from generation to generation

What the important traits of the genetic code?

-umambiguous -contains start/stop signals - degenerate

Properties of an mRNA transcript...

-was made from a DNA template -can be used for translation - was produced by RNA polymerase

A female is a carrier of a recessive, x-linked trait. She produces with an unaffected male. What are the chances that they have an unaffected offspring?

0

Wihtout the special "proofreading" abilities of DNA polymerase, approximately how many errors would occur during DNA replication?

1 in 100,000 base pairs

The steps of DNA replication in prokaryotes:

1. The double helix is separated and unwound 2. DNA polymerase begins the copying process 3. DNA polymerase meet at the termination region

What are the steps of translation?

1. initiation 2. elongation 3. termination

If there are four possible alleles for the "G" gene, how many different alleles does each individual inherit?

2

The hypothesis amoung scientists in the 1950's was that proteins were the genetic material because proteins can contain up to ______________.

20 amino acids

How many children whould we expect to have asteogenesis imperfecta if both parents are heterozygous for this trait?

3/4

The amount of A, T, G, and C varies by species. WIthin a species the amount of A=T and G=C. These are _________ rules.

Chargaff's

Avery, MacLeod, and McCarty demonstrated that ________ was the genetic material.

DNA

In the 1940's, scientists had concluded that the gentic material was most likely either _______ or ___________.

DNA or protein

T or F: DNA polymerase is used during transcription along with RNA polymerase.

FALSE - DNA polymerase is used during DNA replication, but RNA polymerase is used during transcription

T of F: Only one RNA polymerase can transcribe a gene at any given time.

FALSE - it can transcribe many genes at once

T or F: Though DNA strands are antiparellel, the codon-anticodon pairing matches up in a parellel conformation.

FALSE - their in an antiparallel conformation

Which is the lists of the cell cycles in a correct sequential order? (can be in any order)

G1, S, G2, Mitosis

Osteogenesis imperfecta is an autosomal dominant genetic condition. Is it possible for a child to inherit osteogenesis imperfecta from his/her parents if neither of the parents express the condition?

NO -since it is an autosomal dominant disorder, if neither of the parents had the disorder, neither would be able to pass the disease-causing allele to the child

A eukaryotic cell replicates its DNA during the _______ stage (or phase) or interpahse.

S phase

T or F: Blood vessels bring nutrients and Oxygen to cancerous tumors.

TRUE

T or F: Each genetic outcome of a genetic cross between the same parents is indeendant of the others.

TRUE

T or F: It is possible to transfer genes from one type of organism to another type of organism.

TRUE

If cytokensis does NOT happen at the at the end of the cell cycle, what can result?

a multinucleated cell

Pleitropy occurs when __________________________ affect(s) two or more distinct and unrelated traits.

a single mutant gene

One modification to mRNA transcripts is the addition of a tail that is composed of the ______________ nucleotide base.

adenine

The 2 purine bases in DNA are:

adenine and guanine

What did Morgan think was odd about the result of his experiments with X-linked inheritence and fruit flies?

all the recessive individuals were males

SUppose a pre-mRNA transcript has 3 exons: E1, E2, E3. After RNA processing, one mRNA transcript is made up of E1-E2-E3, and another is made up of E1-E2 only. These 2 different transcripts are a result of ____________________ _________ ____________.

alternate RNA splicing

Incorporating new nucleotides into DNA can provide it with the ability to code for a greater number of ____________ ___________.

amino acids

cross-pollination of the garden pea was simple because pollen culd be transsferred from the __________, the male part of the flower, to the ____________, the female part of the flower.

anther; stigma

When 2 molecular strands are connected but oriented in opposite directions, the strands are said to be ______________.

antiparallel

What does DNA ligase do?

attaches DNA fragments

Methemoglobinemia is a(n)....

autosomal recessive disorder

What is the best explination as to why the number of guanines in an organisms DNA is equal to its number of cytosines?

because cytosine pairs with guanin in DNA

The concept of red flowers crossed with white flowers resulting in all pink flowers aligns with an idea of inheritence known as the _____________ concept of inheritence.

blending

WHat method is used by animals for growth and repair of their tissues?

cell division

The animal specific structures that assist with cell division are called _________________________.

centrioles

The attachment point of two sister chromatids is called the _______________.

centromere

Asters radiate from the __________________ toward the ____________ ______________.

centrosome; plasma membrane

During metaphase, spindle fibers function to align ______________ on the metaphase plate.

chromosomes

In prokaryotes, replication can occur in 2 directions at once because the DNA molceule is ________________.

circular

In an autosomal recessive disorder, healthy males will appear as __________ ___________ on a pedigree.

clear squares

Q1 and Q2 are different alleles of a single gene and are both completelt expressed in a heterozygous individual. THis type of inheritence is termed _________________.

codominance

An anticodon is the compliment of the ______________.

codon

WHat is a characteristic of cancer cells?

does not have contact inhibition

Which of the following facilities the binding of tRNA anticodons to mRNA codons?

elongation factors

Which type of inheritence pattern is occuring if one gene is overriding another, such as the gene HERC2 gene producing blue eyes even in the presence of OCA2?

epistatic inheritance

Before a cell undergoes division, the DNA and associated proteins are located within ________________ which appears like a tangled mass of thin threads.

euchromatin

WHich of the following are small proteins that play a structural role in the eukaryotic chromsome?

histones

What genotypes can be determined by a one-trait cross?

homozygous dominant heterozygous

The 2 strands of a DNA double helix are held together by __________ ___________.

hydrogen bonds

If a person inherits a dominant allele but does not express the dominant phenotype, it is referred to as ______________ _______________.

incomplete dominance

The genetic material must have the characteristic of being able to store genetic ______________ about development, cell structure, and metabolism.

information

WHat type of RNA is needed to begin translation?

initiator tRNA

Mitosis follows the G2 stage of ___________ during the cell cycle.

interphase

One function of __________ is that they allow a cell to pick and choose which exons will go into a particular mRNA.

introns

What would contain the most nucleotide bases?

introns + exons

a certain portion of a protein has the amino acid sequence Lys-Gly-Leu. What was the original source of this particular sequence?

it was directed by the bases on the template DNA

WHat does the single-stranded binding protein(SSB) do?

keeps single-stranded DNA apart

During cell division, the protein complexes on either side of the centromere are called ________________.

kinetochores

Specifically, mitosis means ____________ ______________.

nuclear division

The irregularly shaped region that contians the bacterial chromosome is called the _______________.

nucleoid

rRNA strands are transcribed from a template strand of DNA found in the _______________.

nucleolus

Ribosomes participating in production of proteins destined for secretion from the cell are located:

on the E.R.

cancer causing genes are called:

oncogenes

Offspring inherit _______________________________________; if one or both parents passes on a gene with the DNA that does not code for functional proteins, disorders like phenylketonuria can result.

one copy of each gene from both parent

What is the point of replicating prokaryotic or eukaryotic DNA strand at which seperation of the strands occurs to allow for enzyme activity??

replication fork

RNA molecules that contain catalytic propeties and assist with intron splicing are called _____________.

ribozymes

Ribosomes attached to the ER are synthesizing proteins destined for _________________ from the cell.

secretion

What does the DNA double helicase do?

separates double-stranded DNA into single strands

The codon near which the small ribosomal subunit attaches to the mRNA molecule to be translates, which codes for methionine(AUG) is called the __________ codon.

start - anticodons are carried on transfer RNA and coded for specific amino acids

What are the structures for cross-pollination to occur?

stigma, anther, and pollen

The ________ codon binds to a release factor to end translation.

stop

What does the DNA polymerase do?

synthesize DNA, removes RNA and proofreads DNA

What does the DNA primase do?

synthesizes short RNA strands

Mendel bred a plant with a dominant phenotype to an individual with the recessive phenotype. He then analyzed the offspring to deteWHicrmine the unknown genotype. This type of experiment is called a(n) ___________________.

testcross

How many binding sites for tRNA are found on a ribosome?

three

The process of synthesizing an RNA strand from a DNA template is called ___________________.

transcription

What determines the sequence of the rRNA strand?

transcription from DNA template

In griffith's experiment, R strain bacteria acquired a substance from the s strain bacteria. The R strain bacteria was changed or ______________.

transformed

Polyribosomes are strings of ribosomes simultaneously _______________ _________ ___________ strand

translating an mRNA

THe process of ____________ occurs on ribosomes, either free in the cytoplasm or bound to the E.R.

translation

A human cell will contain _____ meters of DNA within the nucleus.

two