Gregor Mendel and Genetics

​Genetics Intro

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What are genetics?

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How can we explain heredity?

Mendel's Genetics

Who was Gregor Mendel?

• Gregor Mendel was a monk and scientist in the 1800s.

• He is known as the "Father of Genetics."

• Mendel studied how traits (observable characteristics) are passed from parents to offspring using pea plants.

Why Mendel Chose Pea Plants

• Why Pea Plants?

  • Pea plants have easy-to-see traits (like purple or white flowers).

  • They grow fast and can self-pollinate (make seeds by themselves).

  • Mendel could control which plants bred with each other.

Mendel’s Idea of “Factors” (Now Known as Genes)

• Mendel’s "Factors"

  • Mendel didn’t know about DNA or genes, so he called them "factors."

  • We now know these factors are genes, the pieces of DNA that decide our traits.

  • Mendel’s idea was that these factors don’t blend; they stay separate.

Law of Segregation

• Law of Segregation

  • Each parent passes down one "factor" (gene) for each trait.

  • These factors can be dominant or recessive.

  • The factors separate when plants make seeds (offspring get one from each parent).

Dominant and Recessive Traits

• Dominant and Recessive Traits

  • Dominant traits: Traits that show up even if there’s only one copy (like brown eyes). (Shown with capital letter- D)

  • Recessive traits: Traits that only show up if there are two copies (like blue eyes). (shown with lowercase letter d)

  • LAW OF DOMINANCE- when two contrasting factors for a character are present, one will dominate over the other. Offspring will inherit the dominant character in the phenotype (Dd)

​Homozygous vs Heterozygous

When the two alleles of a trait are shown as the same type DD or dd they are Homozygous and WILL be expressed

When the two alleles of a trait are different and shown as Dd, they are Heterozygous only the dominant trait will show

** this is for Mendelian Genetics- Modern Genetics shows incomplete dominance.

​Law of Independent Assortment

Law of Independent Assortment

• Traits are passed down independently from each other.

• For example, the color of a flower doesn’t affect the shape of the seed.

• This law explains why there is so much variety in living things!

Why Mendel’s Work Matters Today

Mendel’s Math in Science

• Mendel counted his results and used math to find patterns.

• This made him one of the first to use math in biology!

• His calculations helped show that traits are passed down in predictable ways.

Why It Matters

• Mendel’s laws are the basis of genetics – the study of heredity.

• His work helps us understand how traits are passed down.

• Genetics is important in medicine, farming, and learning about family traits!

Drag and Drop

Mendelian genetics is based on Gregor ​

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discoveries that traits are ​

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through discrete units, or ​

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, which come in pairs of ​

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—one from each parent. These alleles can be ​

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or recessive, determining how traits manifest in offspring based on predictable patterns of inheritance.

Drag these tiles and drop them in the correct blank above

Mendel's

inherited

genes

alleles

dominant

Word Cloud

What terms do we need to remember about genetics?

Match

Match the following

• A basic unit of heredity, a section of DNA that codes for a specific trait

• An allele that is expressed even when only one copy is present

• The molecule that carries genetic information

• A variant form of a gene

• type of gene that does not express its trait unless an individual inherits two copies of the gene

Gene

Dominant

DNA

Allele

Recessive

• Gene

• Dominant

• DNA

• Allele

• Recessive