genetics brainstorm!. c mendel’s studies lead him to conclude that traits are passed on as...
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GENETICS
Brainstorm!
c
Mendel’s studies lead him to conclude that traits are passed on as distinct units (genes).
Artificial selection = selective breedingWhat tool did Greggor Mendel develop?Define dominant & recessive alleleWhat are the principles of dominance?
BB=Bb=bb=
Explain probability & how geneticist use it.
Simple dominance
What other types of dominance are there?
Simple dominance
What other types of dominance are there?
B = Brown eyesB = blue eyes
What 3 terms describe these genotypes?
codominance
A=whiteB=blackAB= black and white hairs called roan
Incomplete dominance
W
WR W
R R
R
W
RR WW
RW
RR RW RW WW
autosomal trait vs sex-linked trait
Autosomal traits are carried on the Autosomal chromosomes (all but the sexchromosomes)
Sex-linked traits are carried on one of thesex chromosomes, X or Y.
Sex linked traits are carried on one of the sex chromosomes.
Sex linked carried on the X
Why do male express sex linked traits more often than females?
What tool do geneticists use to chartinheritance through several generations?
It can be used to show;patterns of inheritancehow traits are passedif trait is dominant or recessive
What do we know about the parents ifshaded in =?
Recessive trait expressed
What are some recessive diseases?
Is this a sex-linked or autosomal trait?How do you know?
What type of trait would cause a pattern of inheritance like this?
What type of trait would cause a pattern of inheritance like this?
Sex linked on X chromosome.How do you know its on the X chromosome?
What are theirgenotypes?
Why would Mendel’s principles apply to All living things?
What is the molecule of inheritance?
Contrast # of chromosomes in body cellsand gametes.
What is the name of the process for each ?What are the products of each?
How and why are they different?
Which circle represents a gamete?How do you know
Mitosis makes 2 diploid body (somatic) cellsthat are genetically identical.
Meiosis makes 4 haploid sex cells (gametes)that are genetically different.
Mutations are a change in the genetic code.
these can occur when there in a change in a gene or a whole chromosome.
types of mutationssubstitutiondeletionpoint mutationframe shift mutation
Chromosomes can be added or deleted bynondisjunction during meiosis.
Nondisjuction results in gametes having the wrong number of chromosomes.
mutation = change in DNA =
change in genotype EE RR =
change in phenotype.
How many traits does a gene mutationeffect?
How many traits does a chromosomalMutation effect?
Why?
Is one always better than the other?
Define selective breeding
What are 2 techniques of selective breeding?
Inbreeding vs hybridization
Which technique provides more variety?Which technique provides specific traits
more often?What is the advantage to more variety?
X =
Is this more likelyto be inbreeding or hybridization?
X =
Is this more likelyto be inbreeding or hybridization?
Which type of breeding makes more variety?
X =
Pure bred vs hybrid
3 causes of genetic variation =mutationsexual reproductiongene shuffling
Genetic Engineering – humans changingthe genetic code.
Steps of Genetic Modification using recombinant DNA technologyGenetic Modification -Occurs when humans manipulate an organism’s genetic make-up.1.Identify the gene for the desired trait and extract
it from the DNA.2.Insert this gene into a bacteria cell’s genetic
material and let the bacteria reproduce.3.Remove the modified genetic material from
many bacteria cells and insert it into a plant cell or zygote.
4.Allow the organism to grow and develop and produce new offspring that carry the trait.
All cells of the new offspring should have the desired trait.
http://www.food.gov.uk/multimedia/flash/gmgame.swf
When a DNA sequence, or gene, from one organism is incorporated into another organism the modified organism is called a transgenic organism.
Transgenic mice & fish
What is the process called when an exact genetic copy of an organism is made?
What is this process called.
How is it done?
autosomal chromosomes
sex chromosomes
Evolution
brainstorm
It appeared at first that there were manydifferent kinds of birds… but on closer inspection many of the different species of birds were all descended from finches.
X =
Natural variation from sexual reproduction,mutations, and gene shuffling means that not everyone in a species is identical.
In artificial selection humans choose whosurvives and reproduces.
In Natural Selection nature chooses whosurvives and reproduces.
What are the 4 mechanical steps of evolution through natural selection?
1.Living things over reproduce:More babies are born then survive.
2.There is variation among the offspring.gene shuffling ( sexual reproduction)
mutations3.Struggle to survive (competition)4.Those that survive have the chance
to reproduce.
Those that have the genetic traits to survivein that environment reproduce and make thenext generation.
Individuals that survive and reproduce are said to be “fit” or exhibit “fitness”
Evidence of Evolution
brainstorm
Evidence of Evolution
comparative embryology
homologous structures
fossil record
vestigial structures
DNA comparisonsThis evidence supports theidea of a common ancestor.
Fossil records are often missing links of evolution.Darwin saw how fossilsshow that earth is very old.
The more similar 2 species are the more recently they shared a common ancestor.
1. More offspring are created than survive.
2. There is variation among the offspring,Due to sexual reproduction & gene shufflingand mutation
3. There is a struggle to survive. (Competition)
4. The individuals that are best suited to the Environment (fit) survive and the future generations look like them.
Main source of inheritable variation.
Main sources of inheritable variation.
Bacteria, which reproduce asexually, can use a process called lateral gene transferin which some genes are swapped (like trading cards) between 2 individuals. Thisprocess gives bacteria more variety and promotes antibiotic resistance in bacteria.
Natural selection on traits that are coded for by one gene (single gene traits) can cause a change in the allele frequency causing a change in the phenotype frequency.
?
Natural selection on traits that are coded for by one gene (single gene traits) can cause a change in the allele frequency causing a change in the phenotype frequency.
Bar graph
Natural selection on polygenic traits (many genes for 1 trait) can affect relative fitness causing 1 of 3 types of selection…
co-evolution occurs when 2 species affect the selective pressures on each other.
Evolution Toxic Newts
According to the Hardy-Weinberg principlewhat 5 conditions are required for genetic equilibrium?
In other words what is required to prevent evolution from occurring.
Conditions required for genetic equilibrium(no evolution).•random mating for each mating•large population•no immigration or emigration•no mutations•no natural selection
(death only caused by old age)
Conditions that promote evolution.
•nonrandom mating (choosing who to mate with)
•small populations
•immigration or emigration
•mutations
•natural selection
One or more of these usually occurs in real populations.
Speciation
How can new species come from existing species?
Brainstorm
How can new species come from existing species?
Reproductive Isolation gives rise to new species.
What are 3 mechanisms that can preventindividuals from the same species from breeding with each other?
Behavioral Isolation: Behavior is a turn off.
Geographic Isolation: They cant get togetherdue to things like distance, bodies of water, mountain ranges, and deep valleys.
Temporal Isolation: Work different shifts and don’t get to meet each other.
Behavioral Isolation: Behavior is a turn off.Eastern meadowlarks don’t respond to western meadowlarks songs.
Geographic Isolation:They can get together
Temporal Isolation:Work different shifts.
Eventually their DNA is so different if individuals fromthe different populations meet and try to reproduce they can not or haveunfertile offspring.
As populations of the species stop interacting their populations experiencedifferent selective pressures causing a shift in the common phenotypes.
Genetic engineering might keep emu tooth genes turned on
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