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INHERITANCE

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Title: INHERITANCE


1
INHERITANCE
2
Interest Approach
  • Pea plants
  • Different colored flowers
  • What was different about each plant??

3
History of Genetics
  • 1670s
  • Scientists believed that each sperm contained a
    little man that would develop into a human
  • Then mother only served as an incubator

4
History of Genetics cont.
  • 1750s
  • Blending of Inheritance Theory
  • Example
  • Black animal mated to a white animal would
    produce a gray animal

5
History of Genetics cont.
  • 1850s
  • Gregor Mendel
  • Austrian monk and worked in the monastery garden
    mating pea plants
  • Determined that characteristic were inherited by
    discrete factors that would eventually become
    know as genes

6
Gregor Mendel
  • Discovered many principles
  • Principle of segregation
  • Principle of independent assortment

7
Principle of Segregation
  • Every individual carries pairs of factors for
    each trait and that the members of the genes
    segregate at random during the formation of
    gametes
  • Since segregation is random, predictable ratios
    of traits are found in the offspring
  • During segregation, chromosomes go from a pair
    (2n or diploid) to singles (1n or haploid). Good
    way to remember

8
  • Hap a diploid is 1n

9
Principle of Independent Assortment
  • Members of each pair of genes are distributed
    independently when the gametes are formed and are
    unaffected by other gene pairs on other
    chromosomes
  • When pairs of genes on different chromosomes
    separate, they have an equal chance or
    probability of going to an individual gamete
  • No predetermined order for the dividing pairs
  • EVERY GENE FOR ITSELF

10
Chromosomes
  • Located in the nucleus of the cell and contain
    all of the genetic material in the cell
  • Arranged in pairs
  • Made up of a substance called DNA

11
Two Types of Chromosomes
  • Haploid
  • Half the diploid or somatic (non-sex cell or
    gamete) number of chromosomes (n or 1n)
  • Diploid
  • Number of chromosomes found in the somatic or
    body cells (2n).
  • Twice the number of chromosomes found in the
    gametes

12
Chromosomes in Animals
  • 1n
  • 30
  • 27
  • 30
  • 40
  • 30
  • 23
  • Cattle
  • Sheep
  • Goat
  • Swine
  • Horse
  • Human

13
DNA
  • Deoxyribonucleic Acid
  • Three Components
  • Deoxyribose sugar
  • Phosphate
  • Four nitrogenous bases
  • Adenine (A)
  • Thymine (T)
  • Guanine (G)
  • Cytosine (C)

14
Nucleotides
  • Combination of the deoxyribose, phosphate and one
    of the four bases
  • Nucleotides bond together to form one strand of
    the DNA molecule
  • Two of the strands wind around each other in a
    double helix to form the DNA molecule

15
In the two pairs of DNA
  • C is always paired with G
  • AND
  • A is always paired with T

16
(No Transcript)
17
The Gene
  • Genes are points of activity found in each
    chromosome that govern the way in which traits
    develop. Genes are specific areas on each
    chromosome and are made up of DNA

18
Protein Synthesis
  • RNA (ribonucleic acid) is a group of molecules in
    charge of reading and translating the genetic
    code for the formation of new proteins
  • RNA uses the DNA as a template to read the code
    in order to produce the right protein with the
    correct order and number of amino acids.

19
Three Types of RNA
  • Transfer RNA (t RNA)
  • Plays a key role in protein synthesis (building).
    Each tRNA molecule can combine with one amino
    acid and can transport the a. a. to the new
    protein building site in the cytoplasm of the cell

20
Three Types of RNA cont.
  • Ribosomal RNA (rRNA)
  • Also plays a key role in protein synthesis. It
    helps control the connecting of the parts of the
    protein (the amino acids) together.

21
Three Types of RNA cont.
  • Messenger RNA (mRNA)
  • Helps complete the building of the protein
  • Physically sequencing the amino acids that were
    carried to the building site by the tRNA and
    chemically connected by the rRNA
  • The mRNA directs the sequence based on the order
    it obtains from the DNA molecule

22
In RNA Translation. . .
C is paired with G T is paired with A A is
paired with U
23
Activity Building DNA
  • Materials Needed
  • Several of each
  • Four different colored gumdrops or other material
    that a toothpick can be inserted into
  • Toothpicks

24
Activity cont.
  • Instructions
  • Designate each color of gumdrops a different base
    (Ared, Tgreen, for example)
  • Designate the toothpicks as the bonds between the
    bases
  • Give the students a list of bases that ranges
    from 10 to 15 bases long
  • The students will then lay out the sequence using
    the gumdrops and the sticking toothpicks into the
    sides

25
Activity Instructions cont.
  • The students must then decide the complimentary
    pair for each base and connect it to the given
    base
  • (to make a double helix other toothpicks must be
    used on the outer sides of the bases to connect
    the pairs of bases together in a rotating matter)

26
Example
Given Gumdrops
Toothpicks to hold bonds together in rotating
matter
T
A
Complimentary Gumdrops
A
T
C
G
Toothpicks
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