1. Learning Objectives How Chromosomes and DNA are connected
How Chromosomes and Genes are connected
Know the 3 types of DNA point mutations
The difference between Haploid and Diploid
The different purposes for Mitosis and Meiosis and why they each end with different results

2. Chromosomes- eukaryotic cellular structures
Chromosomes- eukaryotic cellular structures. Chromosomes are VERY compact strands of DNA. Chromosomes only appear just before cells divide. When not in chromosomes, DNA is uncoiled in the nucleus.

6. (before it copies itself)
Chromosome Structure:
“Sister”
Chromotids
Chromotid
Original
Copy
Centromere
Single Chromosome
(before it copies itself)
Double Chromosome

9. Homologous Chromosomes: in most animals the offspring will get a single “Chromosome” from EACH parent for most traits. So all genetic traits have 2 sets of instructions (1 from Mom, 1 from Dad). So both parents contribute to the genetic make-up of the offspring
Both go to the offspring
(these are NOT
Sister Chromotids, they are HOMOLOGUS
CHROMOSOMES) H W C h w c
Mom’s
Chromosome
Dad’s
Height (H or h)
Weight (W or w)
Hair Color
(C or c)

10. Any Change in the nucleotide sequence of DNA
Genetic Mutation:
Any Change in the nucleotide sequence of DNA
Point Mutations: A type of mutation that cause by an error at single base (a single point) in the DNA sequence.
1) Substitution:
A G C T C
normal
3) Deletion:
A G C T C
normal
A G G T C
mutation
A G C C
mutation
2) Insertion:
A G C T C
normal
A G C A T C
mutation

12. Mitosis: (how your body grows)
-Where a cell divides to make two complete “daughter” cells. Mitosis occurs in a set pattern of phases that is part of “The Cell Cycle”. It never goes out of this set pattern (unless the cell is sick).
Interphase
Mitosis
Cytokinesis
Interphase
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis
Mitosis
“I Prefer Milk and Tea Cold”

13. “I Prefer Milk and Tea Cold”
Mitosis cont:
“I Prefer Milk and Tea Cold”
Interphase  Prophase  Metaphase  Anaphase  Telophase Cytokinesis  Back to Interphase …
(after mitosis)
In Mitosis, cells are dividing to make more cells within the organism. Mitosis is the process of how your body grows to adulthood and how your body repairs itself.
1 Parent Cell (2n)
Daughter Cell
(2n)

14. 2 Daughter Cells (2n) Parent Cell (2n)
2 Daughter Cells
(2n)
Parent Cell
(2n)

16. 4 Gametes (either sperm or egg)
Meiosis: how your cells make gametes
(gametes are sex cells sperm or eggs)
1 Parent Cell (2n)
4 Gametes (either sperm or egg)
All are (n)
2n = “diploid” = 46 chromosomes (in regular human cells)
N = “haploid” = 23 chromosomes (in human gametes)
Mitosis used for Meiosis used for reproduction
growth and repair (produces sperm & eggs)

17. Meiosis: how your cells make gametes
(gametes are sex cells sperm or eggs)
Meiosis: Stages in order
Part 1
Meiosis I
Prophase I
Metaphase I
Anaphase I
Telophase I
and
Cytokinesis
Part 2
Meiosis II
Prophase II
Metaphase II
Anaphase II
Telophase II
and
Cytokinesis

18. 1 Parent Cell (2n) 4 Gamete Cells (n) DNA replication Meiosis I
Meiosis II
4 Gamete Cells
(n)

19. This location is called CHIASMA
Crossing Over: Exchanging of parts of chromatids.
This ONLY happens in Meiosis I (Prophase I)
This location is called CHIASMA
(Synapsis)

20. Video 1
Animation 1

21. Unique aspects
of Meiosis:
Synapsis
Crossing-over
Reduction of
number of
Chromosomes