bio final exam Flashcards
What is this process?
6CO2 + 6H2O + light -> C6H12O6 + 6O2
photosynthesis
where is the light energy harvest during photosynthesis stored?
chemical bonds
where does photosynthesis occur?
the chloroplast
what are the products of photosynthetic electron transport?
NADPH and ATP
how many protein complexes harvest light during electron transport?
2
how do photosystems I and II harvest light?
With pigments
what are the products of photosynthetic electron transport?
NADPH and ATP
which process uses the NADPH and ATP produced by electron transport?
Calvin Cycle
which enzyme “fixes” CO2 from the atmosphere?
RuBisCo
which product of the calvin cycle is used to make sugars?
3-phosphoglycerate
what is the purpose of mitosis?
cell cloning, cell copying, asexual reproduction
what is the cell doing during interphase stage G1
existing
if a cell receives a signal to divide it enters S phase. what happens during s phase?
centrosome synthesis, dna synthesis
in terms of DNA, what is the difference between the G1 and G2 phases?
G2 has twice as much DNA as G1
what happens to the cells chromosomes during prophase of mitosis?
they condense
what happens to the cells centrosomes during prophase of mitosis?
they migrate to two poles
what happens during metaphase of mitosis?
the chromosomes line up in a plane
what happens during anaphase of mitosis?
chromosomes separate into dyads, migrate to two poles
what event is marked by telophase of mitosis?
the chromosomes complete migration
where are the chromosomes during interphase stage G1
in the nucleus
what do we call a place in the cell cycle where division pauses until certain criteria are met?
check point
if a cell fails the G2 or metaphase checkpoint what might happen?
the cell will die
what criteria must be met before a cell can pass the G1 checkpoint?
signal to divide, cell must be large enough, DNA must be undamaged
what do cancer cells lack?
social control, checkpoint control, apoptosis
what type of reproduction is aided by meiosis?
sexual
the number of chromosome “sets” in a cell is referred to as its…
ploidy
what term is used to denote the two chromatids on a single metaphase chromosome?
sister chromatids
what term is used to denote the two chromatids on different chromosomes in a homologous pair?
non-sister chromatids
what distinguishes meiotic prophase I from mitotic prophase?
crossing over between homologous chromosomes
what is separated during meiotic anaphase I?
homologous pairs (tetrads) are separated
at the end of meiosis I, what is the ploidy of the two products?
haploid
what is separated during meiotic anaphase II?
dyads are pulled apart resulting in separate chromosomes
at the end of meiosis II, what is the ploidy of the two products?
haploid
what do we call a mistake in meiosis where homologous pairs do not properly separate?
non-disjunction
every mendelian cross experiment begins with…
true breeding parents
what do we call the phenotypes seen in the F1 generation?
Dominant
Random crossing: what is the dominant trait?
no way to tell dominant or recessive in random cross
mendelian cross: what is the dominant trait?
whatever trait is present in F1 generation
mendelian cross: predict the f2 phenotypic ratio
po: whitexgrey
f1: grey
f2:?
phenotypic f2 ratio is 3:1, 3 grey 1 white
what is the genotype of the f1 generation in a mendelian cross?
heterozygous
what is the genotypic ratio of the f2 generation in a monohybrid mendelian cross?
1:2:1
what is suggested by “two dominant alleles”, aka co-dominance?
both alleles make a functioning product but the products differ from one another. the mixing of the two products creates the intermediate phenotype
which type of inheritance best describes the patterns in this cross?
Po spots x stripes
F1 all have spots & stripes
f2 1/4 spots, 1/2 spots & stripes, 1/4 stripes
co-dominant alleles
what is the best explanation for two independently assorting genes in a dihybrid cross?
the genes are on different chromosomes
how many different allele combinations can be made from two independently assorting heterozygous genes?
4
two independently assorting genes will result in a F2 ratio divisible by
16
what does this description suggest: there is no obvious ratio divisible by 16 in the F2 generation of a dihybrid cross, the parental types are over-represented, and the non-parental types are under-represented
the genes are not independently assorting
what is the source of non-parentals?
crossing over between homologous pairs
DNA is a polymer made of
nucleotides
which best describes DNA synthesis?
each of the two existing strands act as a template to produce a new strand
which best describes DNA synthesis?
the process is catalyzed by several different enzymes
which enzyme synthesizes a new strand of DNA?
DNA polymerase
what does DNA polymerase require?
a free 3’ hydroxyl to attach a new nucleotide
a template strand
unpaired deoxynucleotides
dna polymerase synthesizes new dna…
5’ to 3’
which enzyme makes an RNA primer to begin DNA synthesis?
Primase
why is an RNA primer necessary?
DNA polymerase requires a 3’ hydroxyl to add a new nucleotide
what is a genetic mutation?
a change in the DNA nucleotide sequence
mutations are …
good, bad, or neutral
what are the sources of mutation?
ionizing radiation/gamma radiation/radiations
nitrous acid
DNA polymerase
Oxygen radical
what do we call DNA polymerases ability to correct a mismatch?
exonuclease activity
what do we call a chemical that can cause a mutation?
mutagen
which repair mechanism fixes mutations created by UV light?
excision repair
what is encoded by a gene?
protein
where does gene expression occur?
every cell with a nucleus
during the process of gene expression what is made first?
RNA
what type of RNA is made from a gene?
mRNA, rRNA, tRNA
what functions are performed by the proteins made from genes?
enzymatic
structural
regulation of cell processes
in gene expression, what is transcription?
RNA production
where does transcription begin?
at the promoter
what serves as a template fro transcription?
one of the two strands of DNA
what enzyme catalyzes the transcription of RNA from a DNA template?
RNA polymerase
what is the first event in bacterial transcription?
sigma factor binds
what is transcription?
the process of making RNA from a DNA template
what is translation?
the process of making protein from a RNA template
what marks the beginning of translation?
start codon
every protein begin with…
methionine
what is a genetic codon?
a group of three mRNA nucleotides which can be tanslated into a specific amino acid
what is the role of mRNA in translation?
it is a series of codons that will be translated
what molecule matches each amino acid to the proper codon?
tRNA
what is the role of rRNA in translation?
the “workbench” where translation occurs
translation is terminated by…
one of the three “stop” codons
how can a single nucleotide mutation have no effect on the amino acid content of a protein?
there is redundancy in the genetic code
what role does light energy play? explain which protein complexes harvest it and what it does with the energy
PSII uses the light energy to split a water molecule
PSI re-energizes an e- it received from plastocyanin
at what stage is CO2 utilized? what is CO2 added to and by what?
calvin cycle - Co2 is added to Ribulose-bis-phosphate by RuBisCo
which enzyme fixes Co2 from the atmosphere?
RuBisCo
what is the role of H2O?
it is split by PsII where it provides energy (e-) to move H+’s from the stroma to the lumen. Provides H+ to the lumen
at what stage is C6H12O6 produced?
carbon dioxide fixation, calvin cycle
at what stage is O2 produced? include protein complex
the first step of e- transport, PSII
list two pigments found in photosystems
Chlorophyll-a
Chlorophyll-b
Xanthophyl
Beta-canotene
why do photosystems have multiple pigments?
the more pigments the more wavelengths of light that can be harvested
Characteristics of G1/G0
cell is “existing”
chromosomes are single strands of DNA
characteristics of S phase
DNA is replicated
chromosomes are being replicated
characteristics of prophase
chromatin is condensing
nuclear membrane dissolves
third idk?
characteristics of metaphase
condensed chromosomes align along plane
characteristics of anaphase
chromosomes (chromatids) separate and are pulled to opposite side of the cell
characteristics of telophase
chromosomes stop moving + decondense
nuclear membrane reforms
what is the difference between a chromosome in G1, G2, and metaphase?
G1 - each chromosome is a single strand of DNA
G2 - each chromosome has been replicated and is made of 2 strands of DNA held together by a centromere
Metaphase - each chromosome is condensed for movement
list the three cell cycle checkpoints covered in class and define one criterion for each one that much be met before the cell can continue to divide
G1 - cell has received a signal to divide
Cell is large enough
DNA is undamaged
Sufficient nutrition
G2 - DNA has been replicated, undamaged
Metaphase - all chromosomes are present, undamaged, aligned
goblins are 2n=4
how many chromosomes would be present in a meiocyte in G1 phase (before meiosis begins?)
4
goblins are 2n=4
how many chromosomes would be present in the two secondary meiocytes produced at the end of meiosis 1?
2
goblins are 2n=4
how many chromosomes would be present in the gametes produced at the end of meiosis 2?
2
goblins are 2n=4
what is the ploidy of a goblin meiocyte in G1 phase? (before meiosis begins)
2n
goblins are 2n=4
what is the ploidy of the two secondary meiocytes produced at the end of meiosis 1?
1n
goblins are 2n=4
what is the ploidy of the gametes produced at the end of meiosis 2?
1n
what event distinguishes prophase I of meiosis from prophase of mitosis?
crossing over
how would chromosomes appear at metaphase I and metaphase II?
metaphase I - double planed, metaphase II - single plane
XX X
XX X
how would chromosomes appear in anaphase I? CLICK EDIT
—XX —-
–X X —
describe three events that define prophase I of meiosis
nuclear membrane disintegrates
chromatin condenses
crossing over between homologous pairs of chromosomes
what is one important piece of information you must have known about the individuals used in the Po cross? Mendelian cross
each is true-breeding
what are the possible genotypes for each generation of this mendelian cross?
Po: pointy x rounded
F1: all rounded
F2: 3/4 rounded, 1/4 pointy
Po pointy = aa
Po rounded = AA
F1 rounded = Aa
F2 pointy = aa
F2 rounded = AA, Aa
if a mendelian cross is performed reciprocally, is the outcome the same or different, why?
same, each parent contributes equal amounts of genetic material towards offspring. The f1 would still be heterozygous
Po Line x square
F1 oval shaped
F2 1/4, 1/2, 1/4
what mode of inheritance explains this pattern?
Incomplete/Co
what mode of inheritance explains this pattern?
Po red x blue
F1 purple
incomplete dominance
what mode of inheritance explains this pattern?
Po red x blue
F1 red blue spotted
Co-dominance
Po Line x square
F1 oval shaped
F2 1/4 line, 1/2 oval, 1/4 square
what are the probable genotypes for the following?
Po line = AA
Po square = aa
F1 oval = Aa
F2 line = AA
F2 oval = Aa
F2 square = aa
explain why the phenotype of the F1 generation is unlike either of the parents in the Po generation
Po Line x square
F1 oval shaped
F2 1/4 line, 1/2 oval, 1/4 square
incomplete dominance = the oval is an intermediate of the line + square due to a single “dose” of gene product
co-dominance = the oval is the result of two different enzymes
what is one basic tenet of mendels theory of segregation?
hereditary units occur in pairs called alleles
alleles may or may not be the same
the two alleles segregate from one another during transmission from parent to offspring
females + males contribute equally to the offspring
which of mendels laws is demonstrated by a 9:3:3:1 f2 ratio?
independent assortment
Po: 2 eyes, point x one eye, round
F1: All have 2 eyes and pointy
F2: 9/16 2 eyes, pointy
3/16 2 eyes, round
3/16 1 eye, pointy
1/16, 1 eye, round
predict reasonable genotypes for each gen
Po 2 eyes, pointy: AABB
Po 1 eye, round: aabb
F1 2 eyes, pointy: AaBb
f2 2 eyes, pointy: A_B_
2 eyes, round: A_bb
1 eye, point: aaB_
1 eye, round: aabb
what ratio would be observed instead of a 9:3:3:1 had the two genes been linked?
the parental types would be predominate, there would not be a 9:3:3:1 ratio. if the ratio is at all different, then the genes are linked
Po straight x triangular
F1 all triangular
F2 9/16 triangular
7/16 straight
what mode of inheritance best explains this pattern?
Epistasis
Po straight x triangular
F1 all triangular
F2 9/16 triangular
7/16 straight
predict reasonable genotypes
Po straight = aabb
Po triangular = AABB
F1 triangular = AaBb
F2 straight = A_bb, aabb, aaB_
F2 triangular = A_B_
what is epistasis?
two genes contributing towards one trait
how could two genes contribute to one trait?
the phenotype is created through a metabolic pathway
