Outcome I will compare mitosis and meiosis by

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

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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 n n The process that forms gametes (sex cells) These gametes (sex cells) are sperm and egg cells

Meiosis n Chromosome number is reduced by one-half ¡ ¡ ¡ n 2 n n Diploid (2 n) – 2 copies of each chromosome Haploid (n) – 1 copy of each. End result – 4 haploid gametes

Meiosis n 2 cell divisions

Chromosome Number Organism Human Kangaroo Pegasus Somatic Gametes (Body Cell) (sex cells) 46 23 16 100 8 50

Homologous Chromosomes n n Each cell has 2 copies of each chromosome Homologous chromosomes ¡ Have the same genes in the same locations

2 3 Crossing-over n n Homologous chromosomes exchange parts Results in genetic variation ¡ different combinations of genes 1 1 1 2 3

Fertilization n n Combination of gametes (sperm and egg) to form zygotes Zygote – diploid (2 n) cell (two copies of each chromosome) formed by two haploid cells (1 n + 1 n = 2 n)

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 64 32 32 Body cell 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 448 112 224

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

Web Quest! n n n 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 Groups 2 B Melvin Peter 2 A Nina Yanet 3 B Glenda Sam Leanne 3 A Kerra La. Ronjae 4 B Akirah Alyanna Nick 4 A Malik Jamar 5 B Karen Emma G 5 A Chris Colin 6 B Emma P Jessica F 6 A Jessica S Sophia 7 B Drea Sydney 7 A Jenifer Devon Tanner