1. Biological Anthropology
On Cells, Cell Division, Karyotypes, and DNA

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