GENOTYPE VS. PHENOTYPE

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LEARNING TARGET

I recognize that genes carry information which determines traits.

GENE

The instructions for a specific trait Found on one section of DNA

You have a different gene(s) for each of the following traits: Hair color Eye color Hitchhiker’s thumb Tongue rolling Height

ALLELE The different forms of a gene.

Examples: Hitchhiker’s thumb OR Straight thumb Can roll tongue OR Can’t roll tongue Blonde hair OR Black hair OR Brown hair OR

Red hair

(Note: One allele comes from each parent.)

DOMINANT ALLELES

Alleles that cover up all other alleles. Hides, covers, masks, or over-powers Always shows up when present (it

dominates!)

Shown with UPPERCASE letters.

Examples: H B A

RECESSIVE ALLELES

Alleles that get covered up by any dominant allele.

Shown with lowercase letters.

Examples: h b a

HOMOZYGOUS

When both alleles are the SAME Homo = same

Examples: HH = homozygous DOMINANT hh = homozygous RECESSIVE

HETEROZYGOUS

When both alleles are DIFFERENT Hetero = different

Examples: Hh Qq Rr

GENOTYPE

The genes that an organism has(Genotype = Genes)

Represented by letters

Examples: Hh BB tt Qq

PHENOTYPE The traits or characteristics of an

organism What it looks like

(Phenotype = Features)

Examples: Hair color Eye color Hitchhiker’s thumb Tongue rolling Height

EXAMPLES/PRACTICE

EYE COLOR

BROWN IS DOMINANT TO BLUE

(Use the letter “b”)B = brown allele (dominant)b = blue allele (recessive)

.

BRAD PITTBrown is dominant to blue.

Brad has blue eyes.What is his PHENOTYPE?What is his GENOTYPE?

BRAD PITTBrown is dominant to blue.

PHENOTYPE: blue eyesGENOTYPE: bb

JUSTIN BIEBERBrown is dominant to blue.

Justin has brown eyes.What is his PHENOTYPE?What is his GENOTYPE?

JUSTIN BIEBERBrown is dominant to blue.

PHENOTYPE: brown eyesGENOTYPE: BB or Bb

HAIRLINE

WIDOW’S PEAK IS DOMINANT TO STRAIGHT HAIRLINE

(use the letter “h”)

JOHN TRAVOLTA

John has a widow’s peak.

What is his PHENOTYPE?What is his GENOTYPE?

Widow’s peak is dominant to normal hairline.

JOHN TRAVOLTA

PHENOTYPE: widow’s peak

GENOTYPE: HH or Hh

Widow’s peak is dominant to normal hairline.

LEBRON JAMESWidow’s peak is dominant to normal hairline.

LeBron has a straight hairline.

What is his PHENOTYPE?

What is his GENOTYPE?

LEBRON JAMESWidow’s peak is dominant to normal hairline.

PHENOTYPE: straight hairline

GENOTYPE: hh

SKIN

FRECKLES ARE DOMINANT TO NO FRECKLES

(use the letter “f”)

JENNIFER LOPEZFreckles are dominant to no freckles.

JLo has no freckles.What is her PHENOTYPE?What is her GENOTYPE?

JENNIFER LOPEZFreckles are dominant to no freckles.

PHENOTYPE: no frecklesGENOTYPE: ff

LINDSAY LOHANFreckles are dominant to no freckles.

Lindsay has freckles.What is her PHENOTYPE?What is her GENOTYPE?

LINDSAY LOHANFreckles are dominant to no freckles.

PHENOTYPE: frecklesGENOTYPE: FF or Ff

DIGITS (FINGERS AND TOES)

POLYDACTYLY IS DOMINANT TO 5 DIGITS

(use the letter “d”)

“NORMAL” 5 DIGITSPolydactyly is dominant to 5 digits.

These people have 5 digits.What is the PHENOTYPE?What is the GENOTYPE?

“NORMAL” 5 DIGITSPolydactyly is dominant to 5 digits.

PHENOTYPE: 5 digitsGENOTYPE: dd

POLYDACTYLY (EXTRA DIGITS)Polydactyly is dominant to 5 digits

These people have Polydactyly.

What is the PHENOTYPE?What is the GENOTYPE?

POLYDACTYLY (EXTRA DIGITS)Polydactyly is dominant to 5 digits

PHENOTYPE: PolydactylyGENOTYPE: Dd or DD

ALBINISM (RECESSIVE)

MORE PRACTICE

RIHANNA

Rihanna has brown eyes.What is her PHENOTYPE?What is her GENOTYPE?

Brown is dominant to blue.

RIHANNA

PHENOTYPE: brown eyesGENOTYPE: BB or Bb

Brown is dominant to blue.

LADY GAGAFreckles are dominant to no freckles.

What is her PHENOTYPE?What is her GENOTYPE?

Lady Gaga has no

freckles.

LADY GAGAFreckles are dominant to no freckles.

Lady Gaga has no

freckles.

PHENOTYPE: no frecklesGENOTYPE: ff