1. Biological Anthropology
On Cells, DNA, and Proteins

2. Cell Theory A set of explanatory principles used to understand cells
Cells are the smallest unit of life
Consist of smaller (non-alive) parts: organelles

3. A Cell

4. Two Types of Cells Somatic cells
The vast majority of cells in our bodies
Reproduce through mitosis
Sex Cells (gametes)
Only found in ovaries and testes
Reproduce through meiosis

5. Two Types of Cell Division
Mitosis
Occurs in somatic cells
Produces 2 daughter cells
Genetically identical
diploid
Meiosis
Occurs in sex cells (gametes)
Produces 4 daughter cells
Genetically unique
haploid

6. Mitosis Asexual reproduction Occurs in somatic cells
Produces 2 genetically identical diploid daughter cells

7. Meiosis Occurs in sex cells (gametes) Produces 4 daughter cells
Genetically unique
haploid

8. Crossing-Over # of fingers cerumen ABO group 6 5 6 5 wet dry dry wet A

9. Cell Division
Mitosis Meiosis

10. Karyotype Species-specific set of chromosomes
Differs from species to species in terms of
The number of chromosomes
The sequences of genes contained in the chromosomes

11. Human karyotype 46 chromosomes Arranged in 23 pairs
1 set from each parent

12. Human karyotype Autosomes Are homologous Pairs 1-22 same length
same sequence of genes (may be different alleles)

13. Human karyotype Sex chromosomes X & Y XX – homologous
Pair 23
X & Y
X longer than Y
XX – homologous
XY – partially homologous

14. So what’s in a chromosome?

15. Let’s take a look!

16. A chromosome contains genes

17. and genes contain… Deoxyribonucleic Acid
Present in all living organisms
Amount varies from organism to organism
Species can read each others’ DNA

18. DNA Sugar-phosphate backbone” Bases are “rungs” adenine = thymine
cytosine = guanine

19. the total DNA/genes of a species
Genome
the total DNA/genes of a species
Homo sapiens
app. 3,000,000,000 DNA bases
35,000 – 40,000 genes
Honeybee – 300,000,000 DNA bases
Fruit fly – 13,600 genes
Bacteria – a few hundred to a few thousand genes

20. DNA Replication
Produces two identical strands from one original strand
Each side of the original is a template for making a new copy of its complement

21. The Three Problems
How is the variation present within a species at any time affected by the environment?
Darwin
How is variation passed on from one generation to the next?
Mendel
Where does variation come from?
Watson & Crick

22. But what are genes used for?

23. Protein Synthesis A two stage process Our players: Transcription
Translation
Our players:
Messenger RNA (mRNA) – the locks
Transfer RNA (tRNA) – the keys
Ribosome (“locksmith)
Amino Acids

24. Protein Synthesis 1: Transcription
messenger RNA (mRNA) copy of gene is made
mRNA copy leaves nucleus and goes to cytoplasm

25. Protein Synthesis 2: Translation mRNA copy is “read” by ribosomes
Ribosomes match tRNA to codons on mRNA

26. Proteins: the End Result
One gene codes for one protein
Differences between individuals due (in part) to differences in their proteins

27. Protein Synthesis, once again…
A two stage process
1) transcription
2) translation
The process whereby the DNA message is converted into a protein product

28. for more information… DNA replication
Web sites
Key words
DNA replication
Protein synthesis
DNA translation
Transcription