test 4

NOT the hallmark of prophase

spindle fibers pull chromosomes to opposite ends of the cell

introns in pre-mRNA are_____.

spliced out of the message

an activator protein would have which of the following effects on an operon with a positive control mechanism ?

stimulate transcription when a coactivator is bound to the allosteric site

RNA synthesis is also known as________

transcription

gene expression in bacteria is regulated primarily by:

transcriptional control

genes in euchromatic regions are: ___ active

transcriptionally

if an mRNA transcript of XYZ gene is introduced into a yeast cell, transcript would be:

transplanted into HUMAN XYZ protein

bacterial chromosome is ____shape and Large/Smaller than the cell

circular DNA molecule LARGER than cell

cross over occurs:

prophase I

homologous chromosomes synapse:

prophase I

beadle and tatum began studies with wild type neurospora. how is the organism best characterized?

normal phenotype will grow on minimal medium

triggered by stop codon

termination

x ray diffraction studies are used to determine ____

distance between atoms and molecules.

protein synthesis processing 5'-->3' direction

elongation

Experimental design is used to examine___.

relationship between genetic changes and metabolic enzymes.

eukaryotic transcription factors help DNA ____

replicate

RNA is _____-stranded.RNA contains the nitrous base____, which is NOT found in DNA

single. uracil

individuals with mutations in excision repair enzymes suffer from____due to ____.

skin cancer due to suns UV rays

causes unwinding of DNA double helix

DNA helicase

the bacteriophages used in alfred hersheys and martha chase experiments show:

DNA injected bacteria

if DNA replication rejoined 2 paternal strands, it is called:

conservative

how enzyme activity regulates in feedback inhibition

end product of the metabolic pathway inactivates the first enzyme in the pathway

what happens during nucleotide excision repair?

NUCLEASE removes damaged DNA

Missense

a mutation that replaces 1 amino acid in a protein with another

in the lac operon, cAMP binds to_______

CAP

cytokinesis in plant cells occurs via FORMATION OF______

CELL plate

the chemical group shown in box 1 is

(thymine ) prymidine

which is produced by meiosis

animal gametes

first stage of translation

initiation

certain tRNA anticodons can pair with MORE THAN 1 codon sequence.

wobble hypothesis

Replication process is said to be semiconservative, because a newly synthesized DNA molecule contains 1_____ 1_______.

1 new strand 1 parental strand

An animal with a diploid # of 36 chromosomes will have ___ chromosomes in its gametes and ___ in its somatic cells

18 chromosomes in gametes 36 chromosomes in somatic cells

mRNA codons specifying amino acid leucine is 5'-CUA-3' Its corresponding anticodon is

3'-GUA-5'

which of the following nucleotide sequences represents the complement to the DNA strand5'-AGATCCG-3'?

3'-TCTAGGC-5'

URACIL forms a complementary pair with ___ in RNA and ____ in DNA

Adenine, adenine

some DNA act as introns in some cells cells ( coding sequences) and exons (noncoding sequences)in the cells of other tissues. this is an example of ________. This______(same) allows for formation of_______.

Alternative Splicing-- formation of DIFFERENT TYPES of CLOSELY RELATED proteins

The first scientists to use Griffiths transformation assay to identify genetic material are:

Avery, MacLeod, and McCarty

beadle and tatum irradiated neurospora and initially grew the mutant strains on complete medium. HOW they determined type of mutation for each strain?

By growing the mold on minimal media supplemented with different combinations of amino acids and vitamins

when a mutation occurs during DNA replication, _____ replaces the incorrect nucleotide with the correct one after the mismatched nucleotide has been removed.

DNA polymerase

typical somatic cell cycle consists of _____ and M phases

Interphase

proteins synthesized in bacteria have which of the following in their amino acid terminal end?

N-formyl-methionine

transcriptional activation of the lac operon requires both high lactose and low glucose conditions because ____

RNA polymerase requires CAP in order to BIND to the lac operon promoter, even in the absence of the repressor.

the _____ is responsible for separating chromosomes during ______ phase of mitosis

mitotic spindle. anaphase

errors in DNA replication can come from:

Sun's UV radiation

In Beadle & Tatum Study it was important that NEUROSPORA was haploid BECAUSE:

a mutation that arises is not masked by a normal allele on a homologous chromosome

In tryptophan operon, the repressor actively binds to the operator when:

a tyroptophan binds to an allosteric site on the repressor protein, thereby activating it.

which of the following is a characteristic of URACIL

ability to bind with adenine

cytokinesis in animal cells involves contraction of a ring of_______ microfilaments

actin pus myosin

transcription factors that increase rate of transcription by binding a target in the general transcriptional machinery AND enhance are known specifically as:

activation proteins

inducible operon is usually controlled by

active repressor (keeps it in the OFF state)

In the experiments of griffith, the conversation of nonlethal R strain bacteria to lethal S strain bacteria is an example of ______

an example of TRANSFORMATION,( a genetic exchange)

homologous chromosomes separate and move to opposite poles

anaphase II

sister chromatids separate and chromosomes move to opposite poles

anaphase II

duplicated centrioles move to opposite poles of a a dividing ______ (animal/plant) cell, during ____ phase of cell cycle.

animal. PROPHASE

in order to fix x-ray crystallographic data, the 2 DNA strands must be ______ to each other.

antiparallel

During protein synthesis, ribosomes ATTACH TO____ TO PRODUCE A ______.

attach to mRNA molecule and travel its length to produce a POLYPEPTIDE.

function of kinetochores

attach to microtubules during mitosis

portion of molecules at S is:

attached amino acid

during prophase____ compacts inside chromosomes

chromatin

eukaryotic chromosomes composed of____

chromatin

would would occur if meiosis didn't occur in sexually reproductive organisms?

chromosome number would DOULBE every generation

what allows each strand of DNA to serve as a template for the new DNA during replication?

complementary base pairing between pyrimidines and purines on opposite strands

______ are densley stained, highly compacted and TRANSCRIPTIONALLY INACTIVE regions in chromatin

heterochromatin

function of CAP

increase affinity of promoter region for RNA polymerase

SEQUENCE of events in prokaryotic translation initiation

initiation tRNA binds the small ribosomal subunit--> initiation complex binds to ribose recognition sequence on mRNA--> large ribosomal subunit binds to initiation complex

how are eukaryotic chromosomes replaced

linear DNA molecules replicate from MULTIPLE origins of replication, BI DIRECTIONALLY

which of the following is made from DNA?

mRNA,tRNA,rRNA

process occurring at arrow 3 (sporphyte-->spore--> gamete)

meiosis

WHO confirmed DNA replication is semiconservative?

meselson and stahl

garrod proposed:

metabolic effects due to LACK of enzyme

tetrads line up on cell equator:

metaphase I

the mitotic spindle is made of:

microtubules

mobile genetic elements such as transpose and retrotranspons are significant b/c

mutations caused by retrotranspons contribute greatly to the species of evolution.

DNA synthesis occurs ___(# of times) during each cell generation

once

in the indictable operon, the ______ is the molecular switch controlling gene expression, while the _____is the DNA region where RNA polymerase binds to begin transcription

operator promoter

feedback inhibition is an example of:

post transitional control

Function of Nucleosomes

prevent DNA strands from tangling

homologous chromosomes undergo synapsis during_____.

prophase I

transitional controls of protein levels in bacteria are governed by _______.

rate at which ribosomes attach to mRNA molecules

retroviruses such as RNA tumor virus, use _____ to make DNA from their RNA genomes.

reverse transcriptase

linus pauling demonstrated hemoglobin structure altered by mutation of a ____ gene.

single

____ contain identical DNA sequences, held together by _____during mitosis

sister chromatids, centromeres.

2 molecules that alternate to form backbone of polynucleotide are:

sugar and phosphate

WHICH IS FALSE

sugar present in DNA is ribose

the molecule that connects a growing polypeptide chain and mRNA is called

tRNA

unlike normal cells, CANCER cells can maintain_______.

telomere length as they divide

______, the ends of a eukaryotic chromosomes, shorten with every cell division

telomeres

nuclear envelope FORMS around single stranded chromosomes

telophase II

neurospores are ideal organisms to study effects of genetic mutations . a mutant neurospora strain that cannot make a substance such as an amino acid can still grow if:

that substance is added to the growth medium

when a cell is in metaphase

the chromosomes are aligned at the cell midplane

mutation in IGF2 gene in pigs results in a 3-fold increase of transcriptional activity of this gene in muscle cells, therefore these pigs are leaner and more muscular. B/c this mutation is located in noncoding region of IGF2 gene, we can infer

the mutation alters the regulatory region of the IGF2 region