 Born in 1822  Was a monk and taught high school  He loved working in the monastery gardens  Decided to study inheritance in pea plants  Considered the Father of Genetics

 He chose pea plants because they reproduce quickly and produce large numbers of offspring  He studied seven traits with two contrasting characters: seed shape, seed color, seed coat color, pod shape, pod color, flower position, and plant height

 Genetics – the scientific study of heredity  True-breeding – produce offspring identical to themselves if they self- pollinate  Hybrids – offspring of crosses between parents with different traits

 P generation – the parents of a cross  F 1 generation – “first filial”, the offspring of the P generation  F 2 generation – “second filial”, the offspring of the F 1 generation

 Mendel crossed parents who were true- breeding with opposite traits (tall vs. short)  The F 1 generation all had the same trait (tall)  He then allowed the F 1 generation to self-pollinate…

 …and the other trait reappeared!  ¾ of the offspring had the trait of the F 1 generation, but ¼ of the offspring had the trait that disappeared

 Inheritance is determined by factors (genes) that are passed from one generation to the next.  These genes can come in different forms called alleles.  Law of dominance – some alleles are dominant and others are recessive

 Law of Segregation – during meiosis the alleles separate from one another so that each gamete receives one allele

 Dominant – the trait that is expressed (T)  Recessive – the trait that is hidden (t)  Homozygous – has two of the same allele (TT or tt)  Heterozygous – has one of each allele (Tt)

 Genotype – the genetic makeup of an organism (Tt)  Phenotype – the physical appearance of the trait (tall)  Monohybrid – a cross showing one trait  Dihybrid – a cross showing two traits

Sexual Reproduction and Genetics Punnett Squares  Predict the possible offspring of a cross between two known genotypes

Sexual Reproduction and Genetics Punnett Square— Dihybrid Cross  Four types of alleles from the male gametes and four types of alleles from the female gametes can be produced.  The resulting phenotypic ratio is 9:3:3:1.

Genetic Recombination  The new combination of genes produced by crossing over and independent assortment Sexual Reproduction and Genetics  Combinations of genes due to independent assortment can be calculated using the formula 2 n, where n is the number of chromosome pairs.

 One allele is not completely dominant over another  The phenotype of the heterozygous organism is somewhere in between

 Both alleles contribute equally to the phenotype of the organism  Ex. In cattle red hair is codominant with white hair; cattle with both alleles are roan (have both white and red hairs)

 Genes that have more than two alleles  Ex. Blood type ◦ What are the 4 blood types?  A – I A I A or I A i  B – I B I B or I B i  AB – I A I B  O – ii

Polyploidy Sexual Reproduction and Genetics  Polyploidy is the occurrence of one or more extra sets of all chromosomes in an organism.  A triploid organism, for instance, would be designated 3n, which means that it has three complete sets of chromosomes.

 Traits that are controlled by two or more genes  Ex. Height, skin color

 Mendel’s Principle of Independent Assortment says that the alleles separate during meiosis independent from each other  Thomas Hunt Morgan identified that genes on the same chromosome would move together – they are “linked”

 Sex chromosomes – the chromosomes that determine the sex of the organism ◦ Male – XY  ½ of the sperm with carry an X, the other ½ will carry a Y ◦ Female – XX  All eggs carry an X  Autosomes – all other chromosomes

 A picture of the chromosomes

 Genes that are found on the X or Y chromosome  Most sex-linked genes are found on the X chromosome  Since males only have 1 X, all X- linked alleles are expressed, even if they are recessive  Ex. Baldness, colorblindness, hemophilia

 Down syndrome or Trisomy 21 – caused by an extra 21 st chromosome (nondisjunction)  Turner’s syndrome – females with only one X chromosome (XO)  Klinefelter’s syndrome – males with an extra X chromosome (XXY)

 A type of “family tree” ◦ Circle – female ◦ Square – male ◦ Shaded – has the trait ◦ Unshaded – does not have the trait ◦ ½ shaded – is a carrier of the trait ◦ Horizontal line – represents marriage ◦ Vertical line – connects parents to children

A. Felix Mendelssohn B. Gregor Mendel C. Dr. Reginald Punnett D. Albert Einstein Name the person known as the father of genetics. Sexual Reproduction and Genetics Chapter Diagnostic Questions

A. gamete B. hybrid C. phenotype D. genotype Which term refers to the outward expression of an allele pair? Sexual Reproduction and Genetics Chapter Diagnostic Questions

What is the name for different forms of a single gene that are passed from generation to generation? Sexual Reproduction and Genetics A. alleles B. genotypes C. phenotypes D. traits Formative Questions

Which pair of alleles is heterozygous? Sexual Reproduction and Genetics A. RR B. Rr C. rr D. yR Chapter 10 Formative Questions

In rabbits, gray fur (G) is dominant to black fur (g). If a heterozygous male is crossed with a heterozygous female, what is the phenotypic ratio of the possible offspring? Sexual Reproduction and Genetics A. 1:1 B. 1:2:1 C. 2:1 D. 3:1 Chapter 10 Formative Questions

What is the term for an organism that has one or more sets of extra chromosomes in its cells? Sexual Reproduction and Genetics A. diploid B. gamete C. hybrid D. polyploid Chapter 10 Formative Questions

For human eye color, brown is dominant and blue is recessive. If a husband is heterozygous and his wife has blue eyes, what is the probability that their child will have blue eyes? Sexual Reproduction and Genetics A. 0 B. 1/4 C. 1/2 D. 1 Chapter 10 Standardized Test Practice

A. DD B. Dd C. dd D. dE Which is the genotype of a person who is a carrier for a recessive genetic disorder? Complex Inheritance and Human Heredity Chapter 11 Formative Questions

A. at least one parent is a carrier B. both parents are carriers C. both parents are homozygous recessive D. at least one parent is homozygous dominant Albinism is a recessive condition. If an albino squirrel is born to parents that both have normal fur color, what can you conclude about the genotype of the parents? Complex Inheritance and Human Heredity Chapter 11 Formative Questions

A. heterozygous B. homozygous dominant C. homozygous recessive If a genetic disorder is caused by a dominant allele, what is the genotype of those who do not have the disorder? Complex Inheritance and Human Heredity Chapter 11 Standardized Test Practice

A. Males have only one X chromosome. B. Males have two X chromosomes. C. Males have only one Y chromosome. Why are males affected by recessive sex- linked traits more often than are females? Complex Inheritance and Human Heredity Chapter 11 Standardized Test Practice D. The traits are located on the Y chromosomes.