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Bio 100 Lecture 10-11
Cellular Reproduction
Cell division is:
What has to happen in reproduction?
Note: All cells have a complete set of DNA, held in genes
Note: Genes are grouped onto chromosomes
In cellular reproduction, all DNA must be duplicated (or replicated), and
a copy transferred to the new cell
Prokaryotes
Prokaryotes (single-celled bacteria and archaea) reproduce by binary fission
(“dividing in half”).
• Binary fission of a prokaryote occurs in three stages:
But in eukaryotes…
Prior to cell division, First step is to duplicate chromosomes - produce sister
chromatids
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Bio 100 Lecture 10-11
The Cell Cycle
- Extends from when the cell is first formed from its parent cell to
when it divides.
Two Stages of the Cell Cycle:
Interphase
Mitotic Phase
Interphase
1. Prophase
2. Prometaphase
3. Metaphase
4. Anaphase
5. Telophase (and Cytokinesis)
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Bio 100 Lecture 10-11
Human cells have 26 chromosomes – 22 homologues pairs are autosomes
Meiosis and Reproduction:
Meiosis – the production of gametes
Result of Meiosis:
Gametes
Law of independent assortment
Separation of homologous chromosomes during meiosis can lead to genetic
differences between gametes.
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Bio 100 Lecture 10-11
Chromosomal Set Determination
Chromosomal Abnormalities
Trisomy 21 - Down syndrome
Extra 21st chromosome, distinct look, short stature, possible heart defects,
more common in older mothers
Klinefelter Syndrome
Extra X chromosome XXY - males with some female traits
Turner Syndrome XO – female
Chapter 9: Heredity and Genetics
Gregor Mendel
Mendel’s garden experiment
Mendels Hypotheses:
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Bio 100 Lecture 10-11
Mendel’s Laws
A Pedigree – a family history
Carrier – someone who has the recessive allele but it is not expressed.
Just because a trait is dominant does not mean it is more common.
Genetic Disorders
Autosomal recessive
Cystic Fibrosis
Sickle Cell Anemia
Tay-Sachs disease
Autosomal dominant
Dwarfism
Huntingtons disease
More complex inheritance patterns.
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Bio 100 Lecture 10-11
Study Questions
1. Know mitosis and meiosis.
2. Define autosomal and gamete.
3. Know Mendelian genetics, his hypotheses and laws.
4. Be able to fill out a punnet square and a pedigree.
5. Define dominant and recessive.
6. Know other inheritance patterns.