Chapter 11 Genetics
Mendel's Factors - correct answer-•****Law of segregation-- only pass on half of your
chromosomes passed on-- supported by meiosis -- paired genes will seperate
***Independent assortment--shoe analogy in meiosis 1 -- leads to variation in cells even after
just one meiotic event genetic info inside 4 germ cells is never same- X and Y- will have
chrom 1-22 but 23 will be diff-- nondisjunction may mess this up
Austrian monk turned botanist
• Heritable features-"characters" (genes)
• Variations of characters-"traits" (alleles)
The Blending concept of inheritance
Bf Gregor scientist though parents of contrasting appearance produced offspring of
intermediate appearance -- blending concept of inheritance (red and white flowers cross
would yield pink)--- didnt help Darwins natural selection theory (individuals produced w
selective advantage)-- according to this variation would decrease over time- blend together
Mendel worked with the garden Pea
Easy to cultivate and had short generation time
Could be cross pollinated by transfer from the anther (male part of flower) to the stigma
(female part)
True breeding- all offspring like parent
Studied seed shape, color, and flower color
Observed that offsspring did not posess intermediate charectroistics but rather looked like
one of parents --dissproved blending concept
Ensured his plants were true breeding- tall always had tall offpsring and vise versa-- was
ready to perform cross pollination -- allowed him to form law of segregation
Do all traits blend together- and how he tested for this? - correct answer-No-- if mom had
really light hair and dad had really dark you should theoretically have hair in middle but thats
not always true
Siblings- not the same- not all blends
But can sometimes blend together
• Tested on pea plants-- mendel worked with pea plants
re d and white flowers can blend together to make pink- that is a blending of genes
Also looked at whether tall or short, shape and color of seeds
Cross pollination and monohybrid cross - correct answer-Cross-pollination"
He focused mostly on cross pollination
If remove stamen bf pollutionation you can transfer it to another plant and cross pollinate--
small insects and mammals do this- when they feed on nektar pollin coats their bodies and
then when move from plant to plant cross pollinate
, • "Monohybrid cross"
When crossing diff organisms but just looking at one trait- easy to predict if you know genes
Punnent square -- 4 square for mono
• Generations: P, F1, F2
F1- first offspring f2- second
gene vs allele - correct answer-All have exact same genes- genes that make us humans- diff
versions of those genes are allele(diff eye color)
Difference in Alleles
Sequence of nucleotides-- still making a protein but one making protein for purple flower and
one for white
Not all flowers like this- there is a protein in some flowers where actual code for white protein
not just whether turned on or off
How you get new alleles- through mutation
True breeds and when cross first and second generation - correct answer-2 copies of same
allele (different version of a gene)
Parent plants FF crossing w reccesive ff (homozygous dominant vs. homozygous reccesive)
Meiosis passes on 1 copy of chromosomes-- why only passing one big f or one little f
Heterozygous-- Ff
If cross 2 heterozygous would expect some white to come out in offspring
If cross them and get ½ purple and ½ white
Ff with ff
If cross and get ¾ purple and ¼ white
Ff anf Ff -- would know purple is dominant- it is masking that white
Bw 30,000 and 20,000 different genes is estimate in human genome -- less than 1% of DNA
itself codes for proteins- so what is rest of it? - correct answer-Signals- hey a gene starts
next
Regulation- shouldnt express all these genes here
Only certain ones turned on at certain time
Control sequences-- you can stop here (terminator region)
Can not have something like cyliacs and then those genes can turn on later in life -- trauma
to body can turn on genes
How can you all of have genes for something but they all turn on at diff times of life?
Just bc you have gene doesnt mean you may get it
Epigenetics!!-- factors inducing turning on of genes- kid eats a lot and then diabetes genes
turned on
Hybrids - correct answer-Results when you cross 2 different true-breds
F1 generation
Took f1 and cross bred them and that is in f2 when white shows up again
F2--3:1 ratio almost every time
Law of segregation - correct answer-• 2 alleles for a trait are packaged into separate
gametes
• Meiosis & gametogenesis supports this law
Mendel's Factors - correct answer-•****Law of segregation-- only pass on half of your
chromosomes passed on-- supported by meiosis -- paired genes will seperate
***Independent assortment--shoe analogy in meiosis 1 -- leads to variation in cells even after
just one meiotic event genetic info inside 4 germ cells is never same- X and Y- will have
chrom 1-22 but 23 will be diff-- nondisjunction may mess this up
Austrian monk turned botanist
• Heritable features-"characters" (genes)
• Variations of characters-"traits" (alleles)
The Blending concept of inheritance
Bf Gregor scientist though parents of contrasting appearance produced offspring of
intermediate appearance -- blending concept of inheritance (red and white flowers cross
would yield pink)--- didnt help Darwins natural selection theory (individuals produced w
selective advantage)-- according to this variation would decrease over time- blend together
Mendel worked with the garden Pea
Easy to cultivate and had short generation time
Could be cross pollinated by transfer from the anther (male part of flower) to the stigma
(female part)
True breeding- all offspring like parent
Studied seed shape, color, and flower color
Observed that offsspring did not posess intermediate charectroistics but rather looked like
one of parents --dissproved blending concept
Ensured his plants were true breeding- tall always had tall offpsring and vise versa-- was
ready to perform cross pollination -- allowed him to form law of segregation
Do all traits blend together- and how he tested for this? - correct answer-No-- if mom had
really light hair and dad had really dark you should theoretically have hair in middle but thats
not always true
Siblings- not the same- not all blends
But can sometimes blend together
• Tested on pea plants-- mendel worked with pea plants
re d and white flowers can blend together to make pink- that is a blending of genes
Also looked at whether tall or short, shape and color of seeds
Cross pollination and monohybrid cross - correct answer-Cross-pollination"
He focused mostly on cross pollination
If remove stamen bf pollutionation you can transfer it to another plant and cross pollinate--
small insects and mammals do this- when they feed on nektar pollin coats their bodies and
then when move from plant to plant cross pollinate
, • "Monohybrid cross"
When crossing diff organisms but just looking at one trait- easy to predict if you know genes
Punnent square -- 4 square for mono
• Generations: P, F1, F2
F1- first offspring f2- second
gene vs allele - correct answer-All have exact same genes- genes that make us humans- diff
versions of those genes are allele(diff eye color)
Difference in Alleles
Sequence of nucleotides-- still making a protein but one making protein for purple flower and
one for white
Not all flowers like this- there is a protein in some flowers where actual code for white protein
not just whether turned on or off
How you get new alleles- through mutation
True breeds and when cross first and second generation - correct answer-2 copies of same
allele (different version of a gene)
Parent plants FF crossing w reccesive ff (homozygous dominant vs. homozygous reccesive)
Meiosis passes on 1 copy of chromosomes-- why only passing one big f or one little f
Heterozygous-- Ff
If cross 2 heterozygous would expect some white to come out in offspring
If cross them and get ½ purple and ½ white
Ff with ff
If cross and get ¾ purple and ¼ white
Ff anf Ff -- would know purple is dominant- it is masking that white
Bw 30,000 and 20,000 different genes is estimate in human genome -- less than 1% of DNA
itself codes for proteins- so what is rest of it? - correct answer-Signals- hey a gene starts
next
Regulation- shouldnt express all these genes here
Only certain ones turned on at certain time
Control sequences-- you can stop here (terminator region)
Can not have something like cyliacs and then those genes can turn on later in life -- trauma
to body can turn on genes
How can you all of have genes for something but they all turn on at diff times of life?
Just bc you have gene doesnt mean you may get it
Epigenetics!!-- factors inducing turning on of genes- kid eats a lot and then diabetes genes
turned on
Hybrids - correct answer-Results when you cross 2 different true-breds
F1 generation
Took f1 and cross bred them and that is in f2 when white shows up again
F2--3:1 ratio almost every time
Law of segregation - correct answer-• 2 alleles for a trait are packaged into separate
gametes
• Meiosis & gametogenesis supports this law
