I will compare mitosis and meiosis by completing a double bubble and web quest activity.

Outcome

http://www.youtube.com/watch?v=65BV5dXXxzM

Meiosis & Fertilization

Sexual Reproduction - two individuals produce offspring that have genetic characteristics from both parents (unique – not clones!)

Outcome (proposed): Distinguish between the products of mitosis and meiosis...

Meiosis The process that forms gametes (sex

cells) These gametes (sex cells) are sperm

and egg cells

Meiosis Chromosome number is

reduced by one-half 2nn Diploid (2n) – 2 copies of

each chromosome Haploid (n) – 1 copy of

each. End result – 4 haploid

gametes

Meiosis

2 cell divisions

Chromosome Number

Organism Somatic (Body Cell)

Gametes (sex cells)

Human 46

Kangaroo 16

Pegasus 50

23

8

100

Homologous Chromosomes Each cell has 2

copies of each chromosome

Homologous chromosomes Have the same

genes in the same locations

Crossing-over

Homologous chromosomes exchange parts

Results in genetic variation different

combinations of genes

1 1

1 2 3

2 3

Fertilization

Combination of gametes (sperm and egg) to form zygotes

Zygote – diploid (2n) cell (two copies of each chromosome) formed by two haploid cells (1n + 1n = 2n)

Quick Quiz

 1. Which of these does not occur during meiosis? (2007)

A production of identical gametes

B production of new gene combinations

C crossing-over of homologous chromosomes

D reduction of chromosome number by one-half

2. Sea stars are genetically different from each other and from their parents. These genetic differences are the result of (2006)

A mitosis

B cloning

C sexual reproduction

D asexual reproduction

Practice Questions

3. Horses have 64 chromosomes in each body cell. If a horse cell undergoes meiosis, how many chromosomes should be in each gamete? (2007)

A 16

B 32

C 64

D 128

4. A sperm cell of a moth has 112 chromosomes. How many chromosomes are in the moth’s wing cells? (2005)

A 66

B 112

C 224

D 448

64Body cell

32 32

112 112 224

I will compare mitosis and meiosis by completing a double bubble and web quest activity.

Outcome

Web Quest!

Groups will follow the directions on their paper.

Stay at your assigned lab station! When you are done, there is another

activity to work on.

Computer GroupsGroups

2B Melvin Peter Tanner

2A Nina Yanet3B Kerra Glenda Leanne3A LaRonjae Sam

4B Akirah Alyanna Nick4A Malik Jamar5B Karen Emma G5A Chris Colin6B Emma P Jessica F6A Jessica S Sophia7B Drea Sydney7A Jenifer Devon