Genetics

New Learning Goal:  To describe how genetics are passed from one generation to another.

Fun Facts….  1. Monkeys and Humans have 98.8%of the same DNA.  2. Humans have 50% of the same DNA as bananas.  3. You get 99.9% of your DNA from your parents.

Let’s let my buddy, Bill Nye introduce us to Genetics…. 

copyright cmassengale 5 Gregor Mendel ( ) The Father of Genetics

Gregor Johann Mendel  Austrian monk  Studied the inheritance of traits in pea plants  Developed the laws of inheritance  Mendel's work was not recognized until the turn of the 20th century 6

Gregor Johann Mendel  Between 1856 and 1863, Mendel cultivated and tested thousands of pea plants  He found that the plants' offspring retained traits of the parents copyright cmassengale 7

8  Mendel stated that physical traits are inherited as “particles”  Mendel did not know that the “particles” were actually Chromosomes & DNA Particulate Inheritance

I. What is genetics? i. Genetics The study of _______ (how traits are passed from parents to offspring)

I. What is genetics? i. Genetics The study of heredity (how traits are passed from parents to offspring)

ii. Heredity How an organism passes ____ from one generation to the next.

ii. Heredity How an organism passes traits from one generation to the next.

iii. Trait A __________ or quality of an organism

iii. Trait A characteristic or quality of an organism

v. Variability The differences between ________ in a given population

v. Variability The differences between organisms in a given population

vi. Adaptation A structure or behavior that allows an organism to survive in its environment. sidewinder sidewinder article

Exit Ticket 1. Who is the father of Genetics? 2. What is heredity? 3. What is a trait? 4. Describe adaptation that we saw with the snakes.

1

New Learning Goal:  To describe how genetics are passed from one generation to another.

BrainPop Time…. nddevelopment/dna/

DNA stands for deoxyribonucleic acid This chemical substance is present in the nucleus of all cells in all living organisms The kind of cell which is formed, (muscle, blood, nerve etc.) is controlled by DNA The kind of organism which is produced (giraffe, herring, human, etc.) is controlled by DNA DNA 2

Ribose is a sugar, like glucose, but with only five Oxygen atoms in its molecule Deoxyribose is almost the same but lacks one oxygen atom Both molecules may be represented by the symbol Ribose & deoxyribose 4

The most common organic bases are Adenine (A) Thymine (T) Cytosine (C) Guanine (G) The bases 5

The deoxyribose, the phosphate, and one of the bases adenine deoxyribose PO 4 Combine to form a nucleotide Nucleotides 6

A molecule of DNA is formed by millions of nucleotides joined together in a long chain PO 4 Joined nucleotides 7

In fact, the DNA usually consists of a double strand of nucleotides The sugar-phosphate chains are on the outside and the strands are held together by chemical bonds between the bases 8

PO 4 2-stranded DNA 9

The bases always pair up in the same way Adenine forms a bond with Thymine and Cytosine bonds with Guanine Bonding 10 AdenineThymine Cytosine Guanine

PO 4 thymine PO 4 adenine cytosine PO 4 guanine Bonding continued 11

PO 4 Pairing up 12

The paired strands are coiled into a spiral called A DOUBLE HELIX 13

sugar-phosphate chain bases THE DOUBLE HELIX 14

A model of part of a DNA molecule 15

Build a DNA molecule – you try it!

Your Exit Tickets will be Passed Out Now

CHROMOSOMES

New Learning Goal:  To describe how genetics are passed from one generation to another.

Numbers of chromosomes  Constant for each cell in the body.  Constant throughout the life of an individual (you don’t lose or gain chromosomes)  Constant for all members of a species © 2007 Paul Billiet ODWSODWS

OrganismChromosome numbers Human46 Chimpanzee48 House Mouse40 Maize20 © 2007 Paul Billiet ODWSODWS

Human chromosomes

Identifying chromosomes Chromosomes can be identified by:  Their size  Their shape and flexiblity  Banding patterns Chromosomes are analyzed by organising them into a KARYOTYPE © 2007 Paul Billiet ODWSODWS

Female Male

Y X X X Possible children Father Mother XXXY Chance of a girl 50% Chance of a boy 50% XY XXXXY XXXXY The inheritance of gender

Exit Ticket: On the back of your notes, create a Punnett Square for Blue Eyes and Brown Eyes.

Dominant and Recessive Traits

New Learning Goal:  To describe how genetics are passed from one generation to another.

Before we begin, let’s take a look at a quick video…. 

What are traits?  Physical Traits  Can be seen by others  Eye color, hair color, height, left handed  Acquired Traits  Learned skills  Playing a sport, riding a bike, playing a musical instrument  Behavioral Traits  Instinctual actions  Nest building and migration

Terms Used in Modern Genetics  Genotype  The particular alleles (genes) an individual carries  They are inherited from your biological parents  Genes control your traits  Phenotype  An individual’s observable traits  What people can SEE when they look at you

Terms Used in Modern Genetics  An individual with non-identical alleles of a gene is heterozygous for that gene  Examples: Bb, Tt, Aa  An individual with identical alleles of a gene is homozygous for that gene  Examples: BB or bb, TT or tt Two or more alternative forms of a gene.

Terms Used in Modern Genetics  An allele is dominant if its effect masks the effect of a recessive allele paired with it  Capital letters (A) signify dominant alleles; lowercase letters (a) signify recessive alleles  Homozygous dominant (AA)  Homozygous recessive (aa)  Heterozygous (Aa)

What traits do you have?  We will go through the most common traits that people have  On your sheet, record if you have the mentioned trait or not  You may have to ask your neighbor for help

Detached (EE, Ee) or attached (ee) Earlobes

Can Tongue Roll (TT, Tt) or Can’t (tt)

Dimples (DD, Dd) No Dimples (dd)

Right (RR, Rr) or Left (rr) handed?

Freckles (FF, Ff) No Freckles (ff)

Curly (HH, Hh) or Straight (hh)

Cleft Chin (CC, Cc) or No Cleft (cc)

Allergies (AA, Aa) or No Allergies (aa)

Normal (BB, Bb) Color Blindness (bb) Can you see the number inside the circle? If you cannot, you may be colorblind

Widow’s Peak (WW, Ww) or Straight (ww)

Data  Please compare your results (the chart) with 5 other students.  Does our data support which genes are dominant and which genes are recessive?