Laws of Inheritance Bio 2 By Paulina Bui

Mendel's Five-Part Hypothesis

-A pair of factors (genes) controls traits or characteristics. -One gene from each parent for every trait. -Each trait (e.g..color, shape, texture) is passed from generation to generation. -When gametes (i.e.. sex cells) are formed, the genes separate and are passed to each gamete. -If there are two unlike genes for a characteristic, one may be seen while the other is hidden.

Pea Plant Experiments

-Gregor Mendel studied pea plants to understand how traits are passed from parents to offspring. 1.They reproduce sexually. 2.Their traits are easily observed. -He formed a five-part hypothesis, a possible explanation or answer to a scientific question that is based on prior knowledge or research and is testable.

Reviewing the Principle of Dominance

1.Purple 2.PP Item 1 can be described as the PHENOTYPE. Item 2 can be described as the GENOTYPE. The "p" represents an ALLELE from one parent. A trait that can possibly mask another trait is known as a DOMINANT TRAIT. A trait that is masked is known as a RECESSIVE trait. A plant has the genotype pp. The p can be considered a RECESSIVE trait.

Reviewing the Law of Independent Assortment

A seed has alleles for color (yellow or green) and shape (round or wrinkled). How did Mendel's law of independent assortment describe how these traits were passed from parents to offspring. Check all that apply. -Each trait is passed independently of the other. How are alleles passed for guinea pig fur color and length? One allele for fur color and one allele for fur length is passed to the offspring from each parent.

Pea Plant Experiments

Allele: The gene form for each variation of a trait Phenotype (physically what they looked like): The physical appearance or characteristics seen in organism Genotype: An organism's gene or allele combination

Reviewing Mendel's Pea Plant Experiments

Gregor Mendel studied pea plants to determine the patterns of inheritance. What is not a reason Mendel used pea plants in his experiments? Check all that apply. -They were drought resistant. -They only had two traits to study. Mendel formed a possible explanation for the outcomes he observed in pea plants. Mendel formed a HYPOTHESIS.

Mendel's First Law: Law of Segregation

Law of Segregation: The first law of inheritance, which states that two members of a gene pair separate during the formation of gametes and are distributed so that every gamete receives only one member of the gene pair. Example: Tt --> T--> t -There are alternate forms of genes, known as ALLELES. -An organism inherits one allele from each parent. -A sperm or egg carries only one allele for each trait. -When the alleles are different, one is fully expressed and the other is masked or hidden.

Mendel's Second Law: Law of Independent Assortment

P: RRYY x rryy F1:RrYy x RrYy F2: R_Y R_yy rrY_ rryy Law of Independent Assortment: The second law of inheritance, which states that traits are passed from parents to offspring independently of one another.

Mendel's Pea Plant Experiments

P: YY x yy F1: Yy Yy Yy Yy F2: YY Yy Yy yy

Scientific Statements

Scientific statements must be testable and reproducible. -Hypothesis: A possible explanation or answer to a scientific question that is based on prior knowledge or research and is testable. -Theory: A hypothesis or group of related hypotheses that can be accepted as true based on repeated experimentation with similar results. -Law: A statement of fact that is generally accepted to be true and universal because it has always been observed to be true.

Reviewing Inheritance

The code for heredity is carried on GENES in each organism's DNA. The process of passing traits from parents to offspring is known as HEREDITY. The study of passing traits from parents to offspring is known as GENETICS.

How are traits passed from parents to offspring?

Traits are passed from parents to offspring by genes that code for every trait of an organism and are located in the DNA. The law of segregation is the first law of inheritance, which states that two members of a gene pair separate during the formation of gametes and are distributed so that every gamete receives only one member of gene pair.

Reviewing the Law of Segregation

Which phrase defines a law? -A statement of fact that is generally accepted to be true and universal because it has always been observed to be true. The law of segregation states that allele pairs separate during gamete formation. How then do we have two alleles for a trait? -We receive one allele from each parent.

If a plant with purple petals (PP) is crossed with a plant with white petals (pp), what is the phenotype for the F1 generation?

purple petal

A plant TT for tall height is crossed with a plant tt for short height. The offspring have the genotype Tt. What is the phenotype of the plant?

tall height

A plant heterozygous for yellow pod color (Yy) is crossed with a plant homozygous for green pod color (yy). Which trait is dominant?

yellow pod color