Bio 1A Midterm #2

Producing offspring with same traits as parents generation after generation is ______

true-breeding

To get F2 in his first cross Mendel allowed F1 to _____

self-hybridize

Did Mendel's first cross give blending?

No

Particulate Theory of Inheritance- - Mendel (4)

alternative versions of alleles account for variations in inherited characters, for each character an organism inherits 2 alleles (1 from each parent), if 2 alleles differ, then only one is fully expressed, 2 alleles for each character segregate for gamete production

Mendel's Law of Segregation states that 2 alleles for each character segregate during _____

gamete production

Inheritable unit of DNA that determines a character is ____

gene

Different variations of a gene are called ____

alleles

Mendel's First Law predicts ____ ratio in a monohybrid cross

3:1

Organism's expressed character is called _____

phenotype

Organism's genetic (allelic) makeup is called ____

genotype

Having 2 identical allies for a given character is ____

homozygous

Having 2 different alleles for a given character is_____

heterozygous

In a test cross we cross individual with unknown genotype with _____ _____ individual

homozygous recessive

P/p x P/p would give us ___% PP, ___% Pp and ___% pp

25, 50, 25

In a dihybrid cross we cross individuals with ___ characters

2

heterozygous dihybrid cross gives __:__:__:__

9 3 3 1

Heterozygous dihybrid cross gives __:__ if we look at one character

3 1

Each allele segregates ______ during gamete formation

independently

Trihybrid cross has ___ squares in Punnett Square

64

Multiple alleles are____

two or more alternate forms of gene in a population

In case with multiple alleles an individual has ___

2

dominant allele is NOT ____ or_____

more common, better

Chromosome Theory of Inheritance (2)

genes are located on chromosomes, chromosomes segregate and assort independently during meiosis

Thomas Hunt Morgan uses drosophila because (4)

easy to culture, prolific, short generation time, only 4 pairs of chromosomes

drosophila flies have ___ pair(s) of autosomes and ___ pair(s) of sex chromosomes

3, 1

______ provided evidence for the Chromosome Theory of Inheritance

Thomas Hunt Morgan

standard trait is called______

wild type

w+ is____

wild type

Linked genes ______ assort independently

do not

Recombination frequency is proportional to _____

distance between genes

Formula for distance between genes

# recombinants/#total x 100

linked genes more than 50 map units apart behave ____

as if unlinked

why DNA wasn't always accepted as genetic material (2)

too simple, proteins more likely

Bacterial uptake and expression of genetic material from surroundings is _____

transformation

Recombinant progeny is____

gamete that received chromosome by crossing over

Parental progeny is____

gamete that contained a parental chromosome

______ unwinds DNA

Helicase

______ are points on DNA molecule that DNA polymerase recognizes as starting points

Origins of Replication

lagging strand is replicated discontinuously in ______

Okazaki fragments

DNA polymerase can add new nucleotide to ____

3' -OH

______ attaches to complementary sequence at origin of replication

RNA primer

_______ makes RNA primer

DNA primase

RNA polymerase 1 makes___

rRNA

RNA polymerase 2 makes ____

protein

RNA polymerase 3 makes ___

other structural RNA

3 steps of transcription

initiation, elongation, termination

2 types of control factors

promoter, enhancer

post-transcriptional modification occurs only in _____

eukaryotes

3 types of post-transcriptional modification

5' cap, poly A tail, removal of introns

Non-coding sequences are called ______

introns

RNA splicing is done by ____

spliceosome

Spliceosome removes ____ and splices _____ together

introns, exons

direct relationship between sequences of bases in mRNA and AA sequence of polypeptide is called _____

genetic code

3 bases specify 1 AA (reading unit) _____

codon

General transcription factor binds to a specific sequence in ______

promoter

is promoter transcribed?

no

TATA transcription factor binds to ____

TATA box

_______ protects 5' end from degradation by hydrolytic enzymes (modified guanine)

5' cap

______ added to 3' end may protect against degradation and influence lifespan of RNA

poly A tail

Poly A tail (bunch of AAAA) is added to ____ end

3'

introns removed by spliceosome are then _____

hydrolyzed

3 characteristics of genetic code

non-overlapping, redundant, universal

RNA template carries the same information as ______ strand of DNA

non-template

pre-mRNA has to go through _______ before translation

post-transcriptional modification

Process ending transcription is called _____

termination

RNA Polymerase proceeds elongation until it reaches ___

terminator sequence

Terminator sequence in eukaryotes is _____

AAUAAA

Spliceosome is made up of _____

snRNPs

transcription happens in _____

nucleus

translation happens in _____

cytosol

start codon is ____

AUG

_____ transfers AA from cytoplasm to ribosome and recognizes AA codon

tRNA

tRNA is transcribed in ______ from tRNA genes

nucleus

tRNA is ______ with _____

single polynucleotide, several ds regions

tRNA has AA attachment site at ____ end

3'

______ matches up to appropriate codon

anticodon

ribosomes have __ subunits

2

ribosomal subunits _______ when not involved in protein synthesis

separate

each ribosome has (4)

binding site for mRNA, E site, P site, A site

_______ matches tRNA and AA

aminoacyl tRNA synthetase

attachment of AA to tRNA requires __ phosphates

2

AA are connected into _______ on P-site and A-site

polypeptide chain

tRNA exits ribosome at _____

E-site

3 termination codons

UAA, UAG, UGA

Several ribosomes that translate same mRNA simultaneously are called ______

polyribosome

all translation begins on _____ ribosome

free

Bacteria do/don't have post-translational modification

don't

prokaryotes have _____ transcription and translation

coupled

change in genetic material is called _____

mutation

________ affect one/few bases in a single gene

point mutations

Base substitution leading to different AA is called _____

missense

______ and _____ is change in base # between promoter and terminator

insertion, deletion

Codon changed but codes for the same AA is called _____

silent mutation

Sickle-cell disease arises from ____ mutation

point

In sickle-cell disease _____ _____ is substituted with ____ ____

polar Glu, non-polar Val

_____ is a base substitution that changes codon into stop codon

nonsense

____ is a base substitution that changes stop codon into codon for AA

sense

_____ mutations lead to premature termination of translation

nonsense

2 additional substitution mutations ____ in intron start sequence, _____ in intron end sequence

intron not removed, exon regarded as intron

______ mutation shifts reading frame downstream from insertion/deletion and leads to excessive missense

frame shift