What are we made of?

TEKS & NGSSScience TEKS: Organisms and the environments.

7.14A – Define heredity as the passage of genetic instructions from one generation to the next generation

7.14C – Recognize that inherited traits of individuals are governed in the genetic material found in the genes within chromosomes in the nucleus.

Math TEKS: 7.1B – Number, operation, and quantitative reasoning. Convert between

fractions, decimals, whole numbers, and percents mentally, on paper, or with a calculator

7.12A – Probability and statistics. Describe a set of data using mean, median, mode and range.

NGSS: Disciplinary Core Ideas, LS3.A: Inheritance of Traits Cross Cutting Concepts, MS-LS3-2: Cause and Effect Science and Engineering Practices, MS-LS3-1: Develop and use a model to

describe phenomena.

Check yes or no

Do you have the following traits?

Which traits do you have?

Dominant or Recessive?

Why?

Genetics________: passing characteristics from parent to

offspring

________: branch of biology devoted to the study

of heredity

______: segment of DNA or hereditary unit

Heredity

Genetics

Genes

What we know now

Father of Genetics

Mendel’s Theory of Heredity1. For every trait, there are_______copies of the

gene (one from each parent)two

Mendel’s Theory of Heredity2.There are alternative versions of genes (_________)

alleles

Mendel’s Theory of Heredity3. When two different alleles are present, one is expressed (__________) while the other is not visible (_________).

dominantrecessiv

e

Mendel’s Theory of HeredityBy looking at an individuals alleles, we can

describe their

__________________: genetic makeup

__________________: what they look like

GenotypePhenotype

Alleles can be Dominant or Recessive

Dominant: always expresses itself (capital letters are used to represent dominant alleles)

Example: “B”

Recessive: only expressed in absence of a dominant allele

(lowercase letters are used to represent recessive alleles)Example: “b”

More terms

HomozygousHomozygous heterozygous

Heterozygous

homozygous

Explore:Practice: For each genotype below, indicate whether it is heterozygous (He) or homozygous (Ho).

____RR

____Rr

____TT

____pp

____Hh

____BB

____Nn

____Ll

____ll

____ss

____Tt

____aa

Determine the phenotype for each genotype using the information provided

Round head is dominant over oval head

RR _____________________ Rr ______________________ rr ____________________

Dominant vs. Recessive Allelesin Creatures

Triangle eyes are dominant

Star eyes are recessive

T Triangle eyes t Star eyes

By looking at an individuals alleles, we can describe their Genotype: genetic makeupPhenotype: what they look like

Genotype for Star eyes tt

Genotype for Triangle eyes TT

Tt

Phenotype : Triangle eyes

Phenotype: Star eyes

Head shape Round (R) is dominant over Oval (r)

Eye shape Triangles (T) are dominant over Stars (t)

Eye color Purple (P) is dominant over Orange (p)

# of eyes One eye (E) is dominant over three eyes (e)

Nose slits Three nose slits (N) is dominant over two nose slits (n)

Height Tall (H) is dominant over short (h)

# of legs 4 legs (L) are dominant over 5 legs(l)

# of arms 2 arms (A) are dominant over 4 arms (a)

Skin color Red (C) is dominant over green (c)

Hairiness Hair (I) is dominant over hairless (i)

Hair color Blue hair (B) is dominant over yellow hair (b)

Mouth shape Wide mouth (W) is dominant over narrow mouth (w)

Fingers 3 fingers per hand (F) is dominant over 7 fingers per hand (f)

ElaborateObtain 2 allele cards for each trait (no

peeking)Write down your genotypes on the My

Creature handoutWrite down your phenotypes on the My

Creature handoutDraw your creature

Further Elaboration: Punnett Squares

Punnett Squares

Evaluate• Name three recessive traits

in this alien.

• What are the two possible genotypes for this alien’s number of fingers?

• This alien’s genotype for number of legs is Ll. If it married another alien with genotype Ll, what is the probability that their baby would have five legs? Express as a fraction and percent.

Math Extension  Number as

fractionNumber as decimal

Number as percent

Oval head shape

     

Star eye shape

  

   

Orange eye color

     

Three eyes

  

   

Two nose slits

  

   

Short height

  

   

Five legs   

   

Four arms   

   

Green skin   

   

Hairless   

   

Yellow hair

  

   

Narrow shape

  

   

Seven fingers

     

1. What is the mean percent of recessive traits?_________

2. What is the median percent of recessive traits?_______

3. What is the range in percent of recessive traits?_______