Genetics Guided Notes answer key PDF

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Genetics Guided Notes answer key....

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Genetics Guided N Notes: otes: ANSWER KEY Name: _________ _______________________ ______________ Date: ____________ ________________________ ____________

DNA – Deoxyribonucleic Acid; an acid in the nucleus of a cell that codes and stores genetic information Gene – a section of DNA on a chromosome that directs the making of a specific protein Trait – an inherited characteristic Ex: Eye color, hair color, height, etc. Heredity – the passing of traits from parent to offspring Alleles – the different forms a gene may have for a trait Ex: For the trait of eye color, there are alleles for: brown, blue, green, hazel, etc.

Genetics – the study of how alleles affect generations of offspring Gregor Mendel – “Father of Genetics” •

Studied pea plants

Two Types of Alleles Dominant – the form of an allele that seems to dominate or mask another form of the same allele. •

Written as a CAPITAL letter

Ex: A

Recessive – the form of an allele that appears least often in offspring • •

Written as a lowercase letter Ex: a

Because chromosomes are paired, each individual carries two alleles for any given gene.

Three Possible Allele Pairs Homozygous Dominant – when an individual has two dominant alleles for a gene Ex : AA Homozygous Recessive – when an individual has two recessive alleles for a gene Ex: aa Heterozygous – when an individual has both a dominant and a recessive allele for a gene

Ex: Aa

Let’s go with something simple like which hand you write with: left-handed or right-handed. Which hand you use is determined by a gene in your DNA that tells your body what to do. The DNA that you have in your body was passed to you from your parents – heredity – so your parents determined for you (without knowing it) which hand you would use.

Your DNA is in the form of a duplicated chromosome, because of that each gene has two alleles for which hand you use.

Now, in humans right-handed is much more common (Let’s take a poll to be sure), so we call it the dominant allele. Let’s assign a letter to this dominant allele: R We write it capitalized because it is the dominant allele. Left-handed is less common so we call it the recessive allele. Let’s assign a letter to this recessive allele: r We write it lowercase because it is the recessive allele.

Remember you can have three possible allele pairs RR – homozygous dominant, you are right-handed Rr – heterozygous, you are right-handed rr – homozygous recessive, you are left-handed It all just depends on which alleles are passed on to you from your parents - heredity Genotype – the genetic makeup of an individual Ex: RR, Rr, or rr Phenotype – the physical trait displayed by an individual Ex: Right Handed or Left Handed...