Chapter 6: Heredity and Genetics

Topic 1:

The Mystery of Heredity

On the web

• YouTube: Gregor Mendel; great minds

• Dominant and recessive genes

• virtual experiments

• slide show of inherited traits

• Harry Potter genetics

Item #1

The passing of traits from parents to offspring is known as _______________________. A trait is a physical characteristic of an organism that is largely determined by genetic information, such as eye or hair color. The first scientists credited with major discoveries in the understanding of heredity was __________________________ ___________________.

heredity

Gregor Mendel

Heredity

Item #2

He (Gregor Mendel) decided to limit his investigations to a single organism. He used _________________ _______________________ because he was familiar with them and they grow quickly. They are also able to both ______________-pollinate and ________________-pollinate.

Pea plants

selfcross

Pea Plants

Self-pollination

Item #3

True-breeding results from _____________ - pollination. In this case, the offspring will always have the ________________ traits as the parent.

self

same

Item #4

Cross-pollination results when pollen is carried by _____________________ or _____________________ from one flower to another. This results in a mixing of traits and produces offspring that are not usually identical to their parents.

animals (e.g. bees)wind

Cross-pollination

Item #5

A ___________________________ is a feature that has different forms in a population. The different forms themselves are known as __________________. Three characteristics of pea plants studied by Mendel were _______________________, ________________________, and __________________________.

 

characteristic

traits

seed shape plant height

flower color

NOTE: for the characteristic of: traits included:

seed shape round or wrinkled

plant height tall or short

flower color purple or white

Inherited characteristics in humans

• Include but are not limited to:– Color of eyes, hair, skin (brown=>green=>blue ;

brown=>blonde=>red)– Height and weight (partially environmental)– Pre-disposition to certain “genetic” diseases such as

cystic fibrosis, Huntington disease, diabetes, heart disease, Alzheimer’s disease, melanoma, Tourette syndrome, alcoholism, muscular dystrophy, and macular degeneration.

– Muscle performance– Handedness (right-handed (dominant) ; left-handed)

Continued..– Freckles (dominant); dimples (dominant) ; nose shape ;

earlobe attachment (recessive) ; chin shape (cleft dominant) ; hairline shape

– Blood type (A, B dominant ; O recessive)– Tongue Rolling (dominant)– Male-pattern baldness– Achoo syndrome (dominant)– Myopia (near-sightedness) – dominant– Hand clasping– Amount of body hair– Predisposition to allergies– Curly hair (dominant)*view the inherited traits slideshow