What is genetics? 1 Every sex cell has one allele for each trait. Genetics - the study of how traits are inherited through the interactions of alleles is

A tool used to show possible combinations of alleles Genetics 1 Punnett Squares How could you predict what the offspring would look like without actual mating? Punnett square – A tool used to show possible combinations of alleles

Alleles Determine Traits Genetics 1 Alleles Determine Traits Most cells in your body have two alleles for every trait. These alleles are located on chromosomes within the nucleus of cells.

They show the genotype or genetic makeup, of an organism. Genetics 1 Punnett Squares They show the genotype or genetic makeup, of an organism. The way an organism looks and behaves as a result of its genotype is its phenotype

An organism with two alleles that are the same is called homozygous Genetics 1 Alleles Determine Traits An organism with two alleles that are the same is called homozygous An organism that has two different alleles for a trait is called heterozygous

Put names on top and side Put genotypes Cross top Cross bottom Solving Punnet Squares Draw box Put names on top and side Put genotypes Cross top Cross bottom List genotypes (1 hetero Xx,) List phenotypes (1 albino bird) Calculate number out of 4 (1 of 4) Calculate percentages (25%)

Genetics 1 Making a Punnett Square Dd D d DD dd

In a Punnett square, letters represent Dominant and recessive alleles. Genetics 1 Punnett Squares In a Punnett square, letters represent Dominant and recessive alleles. Dd D d DD dd

An Uppercase (D) letter stands for a dominant allele. Genetics 1 Punnett Squares An Uppercase (D) letter stands for a dominant allele. A lowercase (d) letter stands for a recessive allele. Dd D d DD dd

Genetics Since Mendel 2 Incomplete Dominance When the offspring of two homozygous parents show an intermediate phenotype, this inheritance is called incomplete dominance. Examples of incomplete dominance include the flower color of some plant breeds and the coat color of some horse breeds.

The alleles for blood types are called A, B, and O. Genetics Since Mendel 2 Multiple Alleles Traits controlled by multiple alleles produce more than three phenotypes of that trait. Blood type in humans is an example of multiple alleles that produce only four phenotypes. The alleles for blood types are called A, B, and O.

Genetics Since Mendel 2 Multiple Alleles When a person inherits one A allele and one B allele for blood type, both are expressedphenotype AB. A person with phenotype A blood has the genetic makeup, or genotypeAA or AO.

Someone with phenotype B blood has the genotype BB or BO. Genetics Since Mendel 2 Multiple Alleles Someone with phenotype B blood has the genotype BB or BO. Finally, a person with phenotype O blood has the genotype OO.

2 Multiple Alleles Genetics Since Mendel Allele O is recessive A and B are dominant Father type AB phenotype A B Mother type B phenotype AB Called AB BB Called B

2 Multiple Alleles Genetics Since Mendel Allele O is recessive A and B are dominant Father type A phenotype A Can only be Ao or AA o Mother type B phenotype B AB Called AB Bo Called B Ao Called A oo

Genetics Since Mendel 2 Multiple Alleles When a person inherits one A allele and one B allele for blood type, both are expressedphenotype AB. A person with phenotype A blood has the genetic makeup, or genotypeAA or AO.

Someone with phenotype B blood has the genotype BB or BO. Genetics Since Mendel 2 Multiple Alleles Someone with phenotype B blood has the genotype BB or BO. Finally, a person with phenotype O blood has the genotype OO.

2 Multiple Alleles Genetics Since Mendel Allele O is recessive A and B are dominant Father type AB phenotype A B Mother type B phenotype AB Called AB BB Called B

2 Multiple Alleles Genetics Since Mendel Allele O is recessive A and B are dominant Father type A phenotype A Can only be Ao or AA o Mother type B phenotype B AB Called AB Bo Called B Ao Called A oo

2 Multiple Alleles Genotype Phenotype Ao or AA A Bo or BB B AB oo o Genetics Since Mendel 2 Multiple Alleles Genotype Phenotype Ao or AA A Bo or BB B AB oo o Note in blood typing there is only one recessive – type o The A or B are dominant – which why it is called multiple alleles

Pedigrees Trace Traits Genetics Since Mendel 2 Pedigrees Trace Traits A pedigree is a visual tool for following a trait through generations of a family. Males are represented by squares and females by circles.

Child Child Note children and genetic/blood relatives are connected by the direct white line

Pedigrees Trace Traits Genetics Since Mendel 2 Pedigrees Trace Traits A completely filled circle or square shows that the trait is seen in that person. Half-colored circles or squares indicate carriers. People represented by empty circles or squares do not have the trait and are not carriers.

A pedigree is a useful tool for a geneticist. Genetics Since Mendel 2 Using Pedigrees A pedigree is a useful tool for a geneticist. When geneticists understand how a trait is inherited, they can predict the probability that a baby will be born with a specific trait.

Pedigrees also are important in breeding animals or plants. Genetics Since Mendel 2 Using Pedigrees Pedigrees also are important in breeding animals or plants. These organisms are bred to increase their yield and nutritional content.

Each egg produced by a female normally contains one X chromosome. Genetics Since Mendel 2 Sex Determination Each egg produced by a female normally contains one X chromosome. Males produce sperm that normally have either an X or a Y chromosome.

Genetics Since Mendel 2 Sex Determination When a sperm with an X chromosome fertilizes an egg, the offspring is a female, XX. A male offspring, XY is the result of a Y-containing sperm fertilizing an egg.

Genetics Since Mendel 2 Chromosome Disorders If three copies ( an extra ) of chromosome 21 are produced in the fertilized human egg, Down’s syndrome results.

Recessive Genetic Disorders Genetics Since Mendel 2 Recessive Genetic Disorders Cystic fibrosis is the most common Recessive genetic disorder Can lead to death among Caucasian Americans.

Impact of the Environment Genetics Since Mendel 2 Impact of the Environment Your environment plays a role in how some of your genes are expressed or whether they are expressed at all. Environmental influences can be internal or external. Genes determine many of your traits, you might be able to influence their expression by the decisions you make. Some genetically people at risk for skin cancer limit their exposure to the Sun and take care of their skin, they might never develop cancer.

Biotechnology 3 Genetic Engineering Through genetic engineering, scientists are experimenting with biological and chemical methods to change the arrangement of DNA that makes up a gene. Genetic engineering already is used to help produce large volumes of medicine.

Biotechnology 3 Genetically Engineered Plants Genetic engineering can produce improvements in crop plants, such as corn, wheat, and rice. One type of genetic engineering involves finding the genes that produce desired traits in one plant and then inserting those genes into a different plant.