What makes you, you

1
Genetics

• What makes you, you

2
Genetics

• Genetics is the study of heredity of organisms.
• Genes can be turned on and off and can be seen or
  hide when other genes are present.
• Trait or characteristic is passed from parent to
  offspring

3

• Monohybrid one gene or allele only (hair color)
  (height)
• It is easy to look at one allele at a time, but
  living things have millions of traits the more
  traits the more difficult the study.

4

• Parent P1
• Offspring child of P1 generation and is called
  F1
• Purebred means that both traits are the same.
  (Homozygous)
• Hybrid means that an organism receives different
  traits from the parents (P1) and does not look
  just like either parent. (Heterozygous) This
  causes trait variations and is why no two people
  look the exact same, unless they are identical
  twins.

5

• Gene is a section on a chromosome that codes for
  just one trait. (hair color)
• Allele is one form of a gene (trait from one
  parent)
• Chromosomes humans have 23 pairs of chromosomes
  46. 23 from mom and 23 from dad.
• Chromatid is half of a chromosome.

6

• When traits are passed down from parents to child
  they are randomly sorted and then the childs
  traits vary some or a lot from the parents.
• Dominance is when one trait overshadows another
  trait.
• Dominant allele fully expresses itself over all
  other alleles of its same type.

7

• Recessive traits are over-shadowed by dominant
  ones, they are never visible unless there is a
  pair of recessive traits.
• Recessive allele do not express themselves at all
  if a dominant allele is present.

8

• Homozygous traits both alleles for the trait
  are the same (TT or tt)
• Heterozygous traits both traits are different,
  one dominant and one recessive (Tt or tT)

9

• Phenotype is what the organism looks like. If a
  dominant trait is present that trait will always
  be the phenotype.
• Genotype is what the organisms real gene make-up
  is, it is not always what the organisms looks
  like or is seen by others. Genotypes help to
  explain family backgrounds and other odd traits.

10

• Homozygous Tall bean plant crosses with a
  homozygous tall bean plant
• TT X TT
• T T

T T
T T
T T
T T
T T
11

• Heterozygous tall and a homozygous short plant
  are crossed

T
t
t t
t T
t t
t t
t T
12
Sex Chromosome

• In all sexual reproducing organisms they have a
  pair of chromosomes that allow them to be male or
  female. These chromosomes are passed from mom to
  the egg (ova) and from the dad to the sperm.
  When an ova and sperm combine a new fertilized
  egg is formed called a zygote. When the two
  gametes get together they form the zygote.

13
Sex Chromosome

• XX female, the chromosomes came from mom and
  dad
• XY Male, the X chromosome came from mom and
  the Y chromosome came from dad
• XXX, XXY polyploidy means too many pairs or
  extra chromosomes. Infertile

14
Shared traits

• Another type of trait is co-dominant traits.
  These are sometimes called blended traits. This
  type of trait the alleles from the parents are
  not dominant nor are they recessive, they share
  dominant or are co-dominant.

15
Names of trait problems

• The biological term for one trait is monohybrid.
  This means we look at only one trait and
  disregard the others.
• The biological term for two traits is dihybrid.
  In these cases we look at two traits that move
  together on the same chromatid or next to one
  another on a chromosome. (hair color and eye
  color, bean shape and color)

16
Blended traits

• Blood type, hair color, and flower color are
  examples of this type of trait
• Blood types are A, B, O, and AB
• With blood types the O is recessive and will only
  be seen phenotypic ally if there are two of them
  present
• A and B are co dominant traits and if both are
  present they share the phenotype.

17
Typing

• Parent (mother) type A
• Parent (father) type A
• These are their phenotypes, what are their
• possible genotypes?
• What could their children be?

18
(No Transcript)
19
Pedigree Chart

• These show us the history of a trait or group of
  traits within a given population/family.
  Hemophilia and sickle cell anemia are examples.

20
Family tree project

• You will need to learn some information about you
  and your family.
• There will several traits that you should
  research and collect data on about your family.
• Fill out the individual chart for you and your
  family and have it ready for Fridays class.

21
Samples of dominant and recessive traits in humans

• traits

22
Chart

• Tongue rolling RR Rr rr
• Hair color B bl r
• Eye color B Bg g b
• Ear attachment FF Ff ff
• Second toe length LL Ll ll
• Hitch hiker thumb HH Hh hh

23
Chart
You
Tongue rolling
Hair color
Eye color
Ear attachment
Second toe length
Hitch hiker thumb

T R A I T S
24
Chart
You Mom Dad
Sister Brother
Tongue rolling
Hair color
Eye color
Ear attachment
Second toe length
Hitch hiker thumb

T R A I T S
25
Chart
You Mom Dad
Sister Brother
Tongue rolling R __ R __ R __ R ___ R ___
Hair color B __ B bl B bl bl bl B __
Eye color B g B g B __ B __ B ___
Ear attachment F __ F ___ F ___ f f F __
Second toe length l l l l L l L l l l
Hitch hiker thumb H _ H h H h h h H __

T R A I T S
26
Family Pedigree/Tree

• You will combine at least three traits with your
  new spouse and make a punnett square of the
  possibilities of you F1.
• You will be the P1 and cross to find the F1
• You will create a color family tree showing the
  results.

27

• Father Mother
• You Spouse
  Sister Brother
• Child 1 Child 2

28
Quiz 1 Monohybrid Crosses and Genetics
29

• Cross the following plants
• Heterozygous tall bean plant with a homozygous
  short bean plant. (tall trait is dominant over
  short)
• Show the P1
• Show the completed Punnet Square
• Show the F1 Genotype
• Show the F1 Phenotype

30

• 5. Why is blood typing important and how does it
  link to genetics? Explain.