Download 1 •Mitosis •Meiosis •Sex and Genetic Variability •Cloning

Lecture 7 OUTLINE
Could Scientists Make a Dinosaur?
….Cloning, the Reality
•Mitosis
•Meiosis
•Sex and Genetic Variability
–Chromosomes & Independent Assortment
–Mutations
•Cloning & Molecular Engineering
From DNA to PROTEIN
Mitosis
•Process of FAITHFULLY
copying the DNA CODE
Parent Cell
•Separating the two copies
•Dividing the “parent” cell
in half producing two
“daughter” cells
•Each “daughter” cell has
the same genotype as the
“parent” cell
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Mitosis
Duplicated Chromosomes line up in the middle of the cell
Mitosis
Chromosomes being separated during MITOSIS
DNA Replication & Mitosis is the
same in all organisms
Bacterium
-DNA Replication
- Cell Division
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DNA Replication & Mitosis is the
same in all organisms
•Both strands of DNA are
used as a TEMPLATE for
replication
•The entire genome is
faithfully replicated
DNA Replication & Mitosis
ALL the information for making a
human is contained in EACH and
EVERY one of an individual’s cells!
Who Needs SEX?
•Hydra reproduces ASEXUALLY by budding
•Natural Cloning
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Human Genome Contains 23 Pairs of
Chromosomes
- What would happen if Eggs and Sperm
had the same number of Chromosomes?
Male
Meiosis
The process of reducing
chromosome number in Gametes
Gamete Formation
Diploid Cell
- 4 chromosomes (2 pairs)
Meiosis
Primary Oocyte
(or Spermatocyte)
Secondary Oocyte
(or Spermatocyte)
MEIOSIS I
MEIOSIS II
Secondary Oocyte
(or Spermatocyte)
- 2 chromosomes (unpaired)
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Sexual Reproduction
•Gamete (Egg or Sperm) from one parent
combines its genetic material with a gamete
from the other parent to produce a new
Genotype
2 chromosomes
4 chromosomes
2 chromosomes
Meiosis & Sexual Reproduction
Independent Assortment of Chromosomes
during M e i o s i s produces Genetic Variability
Meiosis & Sexual Reproduction
Independent Assortment of Chromosomes
during M e i o s i s produces Genetic Variability
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Meiosis & Sexual Reproduction
Independent Assortment of Chromosomes
produces Genetic Variability which
increases A D A P T A B I L I T Y
P and p Alleles
• Independent Assortment
produces 4 possible Genotypes
and 2 possible Phenotypes in
Pea Plants
•Recessive alleles may be kept
in the population because they
confer an advantage to the
HETEROZYGOTE
Typhoid caused by
Salmonella bacteria and
CFTR gene
Recombination Further
Increases
Genetic Variability
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Mutations Further Increase
Genetic Variability
Cloning Produces a Individual
who is Genetically IDENTICAL to
the Parent
• Reduced VARIABILITY
• Reduced ADAPTABILITY
• No Need for TWO different sexes!
Animal
Cloning
• Uses the
DIPLOID DNA
from Body Cells
• Enucleated Egg
Cell
• Dolly came from an udder cell from an adult ewe
• Can also use Oviduct cells, Fetal cells, etc.
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Applications
• Clone prize livestock
• Infertile Couples
• Cloned body parts (directed, in vitro,
development of a heart for example)
• Elimination of genetic diseases
• Males no longer needed by society
- but what would that mean for genetic
variability???
• Restocking the world with animals that are
currently extinct!
Could Scientists
clone a Dinosaur?
•In theory if intact DNA can be found the
answer is “YES”!
•Frozen Woolly Mammoth uncovered last year
in the Artic
•DNA probably too fragmented after 10
thousand years
Can Scientists Clone a Dinosaur?
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