Exam 2 Lecture 10-11 Flashcards
What are the characteristics of a tardigrade?
-phylum of animals and microscopic ( <1mm)
-Cosmopolitan- found in all habitats
-segmented and simple head
-4 pairs of lobopodal ( unjointed) legs
->1300 described species
cyptobiosis
state of extreme inactivity that allows organisms to survive in harsh environments
Tun state is described as what?
State to survive desiccation
-body appears to be a lifeless ball.
what are they resistant to?
Environmental extremes, temperature extremes
pressure extremes
and radiation
phylogenetic tree parts ( 5)
-Tip
-Taxa
-Root
-Branch
-Node
Define tip
the most recent part of the tree
Define taxa
the named groups ( clades)
Define root
the most ancient part
Define branch
Single evolutionary line
Node
Common ancestor where the branches converge
Define polytomy in a phylogenetic tree?
Unresolved relationship
Species Tree are what?
Taxons are represented how many times?
Phylogenies that show the relationship among organisms
- taxon’s represented A SINGLE TIME only
Gene trees are what?
Species are represented how many times?
Phylogenies that show relationships among genes
-each species represented multiple times on a single tree
Orthologs are what?
-example ( HOX genes)
pair of homologous genes which have emerged via speciation event
- example HOX 1 in B. floridae and HOX 1 in M. musculus trace their ancestry to a single HOX1 gene in the last common ancestor of these two species
Orthologs are found in what…
Different species
Define paralogs with an example ( HOX gene)
Pair of homologous genes which have emerged through a gene duplication event
-HOX 1 and HOX 2 in B.floridae traces their ancestor to a gene duplication event
Paralogs are found where?
In the same Genome
Paralogs emerge via 2 events.. what are those two events?
-Unequal crossing over
-Whole Genome duplication
During Paralogs unequal crossing over
define homologous recombination
homologous chromosomes undergo reciprocal physical changes of DNA during Prophase 1 of meiosis ( crossing over)
During Paralog unequal crossing over
Define unequal crossing over
and what it can lead to?
An error during homologous recombination
Due to misalignment of chromosomes which leads to gene deletion or duplication
During paralogs
Define non-disjunction
the failure to complete anaphase during meiosis 1 OR 2
During non-disjunction describe what fails in meiosis 1 and 2
Meiosis 1- failure to separate homologous chromosomes
Meiosis 2- Sister chromatids fail to separated
During paralogs
Define whole genome duplication
Major mutation that occurs when an ENTIRE set of chromosomes is duplicated in a cell
Whole Genome duplication ( in paralogs) results in what?
Polyploidy- more than 2 sets of each chromosome type
Whole genome duplication ( in paralogs) is caused by what? ( 3 things)
1.) Nondisjunction
2.) cytokinesis failure
3.) multiple fertilizations
Whole genome duplication ( in paralogs) is caused by 3 things. of these three is cytokinesis failure
Define cytokinesis failure
Failure of the cytoplasm of a single cell to physically divide into two separate daughter cells during meiosis or mitosis
Whole genome duplication ( in paralogs) is caused by 3 things. of these three is Multiple fertilization.
Define Multiple Fertilization?
Literal definition- of multiple fertilizations of eggs/ovule by sperm/pollen grains
CENTRAL DOGMA of molecular biology is what?
A theory stating that genetic information flows only in one direction, from DNA, to RNA, to protein, or RNA directly to protein
Different alleles are coded for what?
Slightly different proteins with slightly different functions
Central dogma consist of 3 processes. what are they?
1.) transcription
2.) translation
3.) DNA replication
Define translation?
- specific RNA
- what does it code for
The process where RNA, specifically messenger RNA (mRNA) codes for proteins
Define transcription
a synthesis of RNA molecule
-DNA is copied to RNA.
In transcription
Define template strand
DNA strand that acts as a template for synthesis based on complementarity of nucleotides
In transcription
Define coding strand
Carries genetic code for protein synthesis
DNA complementations to what?
RNA
What are the complementation’s from DNA to RNA ( A,C,G,T)
A-U, T-A, G-C, C-G
complementation’s are determined by what type of bonds?
Hydrogen bonds
In transcription
Define RNA polymerase
an ENZYME that synthesizes RNA
RNA is synthesized in what direction
5’-3’
DNA is synthesized in what direction
3’-5’
Nucleotides have [blank #1] triphosphate groups and [blank#2] hydroxyl groups
what are the blank numbers?
1.) 5’
2.) 3’
Phosphodiester bonds form between what?
3’OH and of RNA transcript strand and 5’ triphosphate group of incoming RNA nucleotide by RNA polymerase.
Define Transcription Factor
and what it influences?
regulatory protein that binds to DNA near the promoter of a gene to influence transcription
Define homeodomain
60 Amino acid long DNA binding region of these particular transcription factors
Transcription factors influence what? ( Hint; think of the 3 W’s)
1.) WHEN
2.)WHERE
3.)HOW
much a gene is transcribed
Transcription factors bind to what and where?
binds to transcription factor binding sites
near the promoter
Define transcription factor binding site
the specific DNA sequence to which a transcription factor binds
Define promoter
A region of DNA where RNA polymerase binds to transcription
Define RNA polymerase II
Enzyme that synthesizes specifically mRNA
what is gene expression
and what does it pattern for?
When, where, and how much gene is transcribed
- patterns for developmental transcription factors underlie anatomical patterns
How do we detect gene expression patterns?
HCR ( hybridization chain reaxtion)
fluorescence in situ hybridization (FISH)
HCR-FISH is a method that does what?
Labels specific mRNA targets with fluorescent molecules ( called fluorophores)
HCR-FISH enables what?
Detection of single mRNA molecules
What is a flurorphore
Emits light when it is excited by a laser with a specific wavelength of a light
In HCR-FISH define initiator probe
DNA molecule that is complementary to target RNA, so binds to it
What does the initiator probe include?
a tail that is complementary to part of the second DNA molecule called amplifier probe A, so they bind
In HCR-FISH define amplifier probe A
tail that’s complementary to part of amplifier probe B so they bind
In HCR-FISH define amplifier probe B
tail that’s complimentary to amplifier probe A so they bind
Each amplifier probe carries what
a fluorphore
what is the outcome of HCR-FISH
a fluorescent single strong enough that we can detect the location of a single mRNA molecule
In developmental transcription factors
-they interact in what?
In complex regulatory networks
In developmental transcription factors
-these factors regulate what?
( what happens during development )
expression of other transcription factors
- get more complex through development
Complex expression patterns underlie development of complex anatomical patterns by doing what?
controlling cell proliferation and shape change.
