11.1 Reproduction I. Asexual Reproduction (Single Individual involved) A. Offspring created is genetically identical to the parent B. Examples 1.Binary fission a. process by which prokaryotes reproduce 2. Fragmentation a. the body breaks into several pieces, some or all regrow missing parts into complete adults 1. Example – starfish 3. Budding a. new individuals split from existing ones 1. animal example – hydra & plant example – potato 4. Parthenogenesis a. process in which a female makes a viable egg that grows into an adult without being fertilized by a male

II. Sexual Reproduction A. Two parents give genetic material to produce offspring that are genetically different from their parents B. Fertilization 1. each parent produces a gamete that come together to form a zygote C. Cell Types 1. germ cells – only cells that make gametes 2. somatic cells – all other body cells D. Advantages to Sexual Reproduction 1. Asexual reproduction produces many offspring in a short amount of time but with very little variation 2. Sexual reproduction allows for variation in a species which can respond to a changing environment.

III. Chromosome Number A. Each species has a particular number of chromosomes

B. Haploid Cells (aka gametes, aka sperm & egg cells) 1. contain ½ the number of chromosomes of somatic cells, NO PAIRS! 2. the symbol “n” is used to represent the number of chromosomes a. ex. – in humans, n = 23 C. Diploid Cells (aka somatic cells) 1. has two sets of chromosomes 2. in humans that number is 46 a. ex. – in humans, 2n = 46

D. Homologous Chromosomes 1. Similar in size & shape 2. Have info. for same traits 3. Humans have 23 pairs or 46 total 4. One from mom and one from dad E. Autosomes 1. chromosomes that do not determine the sex of a person 2. these make up 22 of the 23 chromosomes in every cell F. Sex Chromosomes 1. Determine the sex of a person 2. Only 1 of the 23 sets of chromosomes 3. Referred to as X and Y a. males are XY and females are XX