Genetics The study of genes and the inheritance of traits Discovered by Gregor Mendel- an Austrian Monk First experimented with Pea plants- see your booklet!

Characteristics These are features you exhibit physically These are features you exhibit physically ( your looks) ( your looks) Example: Eye color – green Also called the Phenotype

Traits The different versions of a characteristic The different versions of a characteristic Example: blue, green, and brown eyes Example: blue, green, and brown eyes

Inheritance Occurs when traits are passed down from parent to child. Occurs when traits are passed down from parent to child. These traits or inherited characteristics may be obvious- we can see them in the phenotype or not physical- they only appear in the genotype. These traits or inherited characteristics may be obvious- we can see them in the phenotype or not physical- they only appear in the genotype.

Genes Bits of information passed down from parent to child. Bits of information passed down from parent to child. Made of chemicals called DNA. Made of chemicals called DNA. Think back to the DNA information earlier in the term Think back to the DNA information earlier in the term

Genetic Diseases Can be passed on through genes from a parent to the child.- remember mutations in the genetic code! Can be passed on through genes from a parent to the child.- remember mutations in the genetic code! Example : Marfan Syndrome Example : Marfan Syndrome (Individual is tall, has long arms and legs) Hemophilia- a bleeding disorder (Individual is tall, has long arms and legs) Hemophilia- a bleeding disorder HOMEWORK- 1 paragraph on Marfan Syndrome or Hemophilia

Reproduction Sexual – Sperm fertilizes an egg to produce offspring Sexual – Sperm fertilizes an egg to produce offspring - MEIOSIS- more to come on this and it’s in your booklet - MEIOSIS- more to come on this and it’s in your booklet Asexual – occurs when 1 organism copies itself to produce offspring Asexual – occurs when 1 organism copies itself to produce offspring -budding eg hydra -budding eg hydra -runners- grasses -runners- grasses

Reproduction Continued… Asexual reproduction Asexual reproduction - no variation unless by mutation - no variation unless by mutation -genetically identical -genetically identical Sexual Reproduction Sexual Reproduction -variation in a population -variation in a population -four gametes via mitosis …more to come on this process -four gametes via mitosis …more to come on this process *** In sexual reproduction all gametes (egg or sperm ) are different –even though they have the same number of chromosomes with the information on the same characteristics, the specific information is different *** In sexual reproduction all gametes (egg or sperm ) are different –even though they have the same number of chromosomes with the information on the same characteristics, the specific information is different

Mitosis- Asexual reproduction Stages of Mitosis Stages of Mitosis -it’s a continuous process -it’s a continuous process -produces two identical daughter cells -produces two identical daughter cells

MEIOSIS Stages of Meiosis Stages of Meiosis -produces 4 daughter cells- -produces 4 daughter cells- non-identical non-identical Daughter cells have a haploid number of chromosomes- Daughter cells have a haploid number of chromosomes- Or half the number of the parent cell (or the diploid number) cell (or the diploid number) These are called the gametes (egg or sperm) Info & Quest: SW3 PG 182 Pearsons : pg & 15 Pracs- observing meiosis and mitosis

Fertilization Occurs when a sperm unites with an egg Occurs when a sperm unites with an egg This is what unites an egg and a sperm and restores the chromosome number to the diploid or full number of chromosomes for each species i.e. 23 to 46 in humans This is what unites an egg and a sperm and restores the chromosome number to the diploid or full number of chromosomes for each species i.e. 23 to 46 in humans pg 15 Pearson- Unit review questions- will have copies for 2012 pg 15 Pearson- Unit review questions- will have copies for 2012

Offspring Another name for the children of a male and female parent Another name for the children of a male and female parent Or the result of any reproductive process- also used when talking about peas or flowers or cows etc. Or the result of any reproductive process- also used when talking about peas or flowers or cows etc.

Mutations again- SW3 PG 188/ Pearson’s Pg 22 Occurs when genes make a mistake mixing and produce new or different traits in the offspring. Occurs when genes make a mistake mixing and produce new or different traits in the offspring. These are usually fatal…but can just produce offspring with issues! These are usually fatal…but can just produce offspring with issues! Check the booklet for Klinefelter and Turners syndrome Check the booklet for Klinefelter and Turners syndrome

Genotype A combination of alleles A combination of alleles Example: TT, Tt, or tt Example: TT, Tt, or tt This means we can’t see it! Its in the genes We use a Capital letter for dominant traits and a small or lower case letter for recessive traits. Your booklet has information about this and some practice examples

Phenotype They are the traits determined by reading the genotype. They are the traits determined by reading the genotype. Example : FF = black fur Example : FF = black fur Black fur is the phenotype or trait Black fur is the phenotype or trait

Alleles T – is considered a dominant allele T – is considered a dominant allele t – is considered a recessive allele t – is considered a recessive allele TT – is dominant Tt or tT – is dominant tt - is recessive

How do we determine which “allele” some one gets? Looking at Dominant and recessive traits and intermediate inheritance and sex linked traits Looking at Dominant and recessive traits and intermediate inheritance and sex linked traits Booklet information/ text book –Science world 3 pg or Pearsons- pg Booklet information/ text book –Science world 3 pg or Pearsons- pg Looking at Pedigrees and Punnet squares Looking at Pedigrees and Punnet squares Pedigrees in Booklet Pedigrees in Booklet Plus SW3 pg 198 Plus SW3 pg 198 Little bit! Pearsons pg 22 Little bit! Pearsons pg 22

Pedigrees

Punnett Square Uses mom and dad’s genotypes to determine the possible traits of their offspring. Uses mom and dad’s genotypes to determine the possible traits of their offspring. 4 offspring 4 offspring -draw this in your books -draw this in your books Mum has Brown eyes – Homozygous Mum has Brown eyes – Homozygous Dad- Brown eyes heterozygous Dad- Brown eyes heterozygous

Sex linked traits… Sex linked means the trait is only passed on through the X chromosome. As these are the sex chromosomes it is called either sex linked or X linked Sex linked means the trait is only passed on through the X chromosome. As these are the sex chromosomes it is called either sex linked or X linked See hand out on X linked chromosomes See hand out on X linked chromosomes OR pg 22 Pearson’s OR pg 22 Pearson’s Or 202 SW3 Or 202 SW3

Gene technology/Human Endeavour Look at photocopies from Pearson's Text and class discussion Look at photocopies from Pearson's Text and class discussion Pg 31 Pearson’s Pg 31 Pearson’s Either photocopy and read and discuss Either photocopy and read and discuss Or Or Research stem cells and the applications for this research in a computer room Research stem cells and the applications for this research in a computer room Or GM foods Or GM foods

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