year 10 science genetics
DESCRIPTION
Year 10 science genetic lesson. Cover Punnett squares, Alleles, recessive, phenotypes, genotypes, homozygous, heterozygous and basic blood typesTRANSCRIPT
![Page 1: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/1.jpg)
Punnett squares and uses. Genes (Alleles). Why are some genes dominant and
others recessive? How do we write symbols for these genes?
What is homozygous and heterozygous?
Predict phenotypes from genotypes. Test crosses. Blood Types.
![Page 2: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/2.jpg)
Diagram used to determine genetic crosses
A a A a
![Page 3: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/3.jpg)
Diagram used to determine genetic crosses
A a A a
AA
![Page 4: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/4.jpg)
Diagram used to determine genetic crosses
A a A a
AA Aa
![Page 5: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/5.jpg)
Diagram used to determine genetic crosses
A a A a
AA
Aa aa
Aa
![Page 6: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/6.jpg)
Use different Letters or Symbols
G @ B @
![Page 7: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/7.jpg)
Use different Letters or Symbols
G @ B @
BG
![Page 8: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/8.jpg)
Use different Letters or Symbols
G @ B @
BG B@
![Page 9: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/9.jpg)
Use different Letters or Symbols
G @ B @
BG
G@ @@
B@
![Page 10: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/10.jpg)
Worksheet Q 1-6 Planners - Tuesday 13/3/12
![Page 11: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/11.jpg)
Genes are how living organisms inherit features from their ancestors
What did you inherited from your parents' genes
Genetics tries to identify which features are inherited, and explain how these features are passed from generation to generation.
![Page 12: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/12.jpg)
Different forms of a gene Your ear lobes are inherited From your DNA Genes (Alleles) are inherited as
units, with two parents dividing out copies of their genes to their offspring.
![Page 13: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/13.jpg)
The ear lobe is controlled by 2 alleles.
Mum and Dad
YOU
![Page 14: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/14.jpg)
A DOMINANT allele covers up the recessive form.
A recessive allele gets covered up in the presence of a dominant allele
A DOMINANT allele is represented in CAPITALS
i.e. L – for an attached lobe as this is dominant
a recessive allele is represented in lower case
i.e. l – for an unattached lobe as this is a recessive allele
The dominate allele will be seen.
![Page 15: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/15.jpg)
Phenotype – is the physical characteristic of the gene ie attached lobe
Genotype is the combination of alleles (genes) that make up the gene – represented in letters. LL, Ll (lL), ll
![Page 16: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/16.jpg)
L – for an attached lobe l – for an unattached lobe 2 alleles.
LL ll Ll
![Page 17: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/17.jpg)
L – for an attached lobe l – for an unattached lobe
LL ll Ll
![Page 18: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/18.jpg)
L – for an attached lobe l – for an unattached lobe
Phenotypes
LL ll Ll
![Page 19: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/19.jpg)
L – for an attached lobe l – for an unattached lobe
Phenotypes
Genotypes LL ll Ll
![Page 20: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/20.jpg)
Homozygous – the same allele – LL or ll
Heterozygous – different allele - Ll
![Page 21: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/21.jpg)
Mum has a heterozygous ear lobe, Ll and Dad has a recessive ear lobe, ll (thus Homozygous). What ear lobe will their children have?
Mum = Ll Dad = ll I I L Ll Ll I ll llPunnett Square
![Page 22: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/22.jpg)
Mum has a homozygous ear lobe that is attached and Dad has a recessive allele ear lobe. What ear lobe will their children have?
Mum = LL Dad = ll I I L Ll Ll L Ll LlAll the childen will have Ll Genotypes
their ear lobe genes are hetrozygous.
![Page 23: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/23.jpg)
LL Ll ll
![Page 24: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/24.jpg)
Two black fish look the same but have different genotypes. The fish with genotype BB is said to be homozygous, or pure breeder because both the alleles for the skin colour gene are the same. The other fish is said to be heterozygous or Hybrid, because its two alleles for skin colour gene are different.
What offspring can occur when the fish cross breed, that is BB & Bb.
What offspring can occur when 2 heterozygous breed?
![Page 25: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/25.jpg)
Incomplete dominance is a condition when neither allele inherited is dominant or recessive over the other
This will result in a blend/fusion of characteristics
An example of this is in snapdragons, a flower where its colour can be red, pink, or white. A white (WW) snapdragon crossed with a red
(RR) snapdragon produces all pink offspring The heterozygous (RW) condition results in
pink flowers.
![Page 26: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/26.jpg)
RED = RR White = WW RW RW RW RW All the off spring will be RW –
Pink
R RWW
![Page 27: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/27.jpg)
![Page 28: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/28.jpg)
When both alleles contribute to the phenotype of an organism
Ex.) Speckled Chickens
![Page 29: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/29.jpg)
Black = BB White = WW
BW BW BW BW All the off spring will be BW –
Black with White
B BWW
![Page 30: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/30.jpg)
BW offspring = BW White = WW
BW WW BW WW The off spring ratio would be 1:1 BW:WW
B WWW
![Page 31: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/31.jpg)
When more than two possible alleles exist in a population
Ex.) blood type IA
IB
i
Dominant
Recessive
![Page 32: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/32.jpg)
Video on blood types
![Page 33: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/33.jpg)
Human Blood TypesPhenotype Genotype
A
B
AB
O
IAIA or IAi
IBIB or IBi
IAIB
ii
![Page 34: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/34.jpg)
Traits controlled by two or more genes
Ex.) eye color, skin color
![Page 35: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/35.jpg)
The characteristics of any organism, is not only determined by the genes it inherits
Characteristics are determined by interactions between genes and the environment
Ex.) genes may affect a plants height but the same characteristic is influenced by climate, soil conditions and availability of water
![Page 36: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/36.jpg)
Human hair is inherited by incomplete dominance. Human hair may be curly (CC) or straight (cc). The heterozygous genotype (Cc) produces wavy hair. Show a cross between two parents with wavy hair
![Page 37: Year 10 science genetics](https://reader033.vdocuments.mx/reader033/viewer/2022061203/547de800b37959892b8b53da/html5/thumbnails/37.jpg)
A man is suing his wife on grounds of infidelity. The man claims that the child is blood type O and therefore must be fathered by someone else. Can he use this evidence in court if he and his wife both have heterozygous B genotypes?
Show the cross of the two parents