Reproduction

Reproduction When organisms (living things) produce more of their own kind. Required for the survival of the SPECIES There are 2 types of reproduction:

I. Asexual Reproduction Does NOT involve the union of sex cells Only 1 parent Offspring is genetically IDENTICAL to the parent Ex: binary fission (bacteria), budding, regeneration, etc.

Binary Fission (bacteria and protists)

Budding (Yeast)

Budding (Hydra)

Regeneration

Asexual Reproduction New Organisms develop from a cell or cells of a single parent Have characteristics (traits) identical to the parent Done by mitosis No genetic variation

How do cells multiply?? MITOSIS Cells multiply by dividing themselves in HALF MITOSIS – asexual reproduction Click below for mitosis animations http://www.johnkyrk.com/mitosis.html http://www.biology.arizona.edu/cell_bio/tutorials/cell_cycle/MitosisFlash.html http://biology.about.com/library/blmitosisanim.htm http://www.cellsalive.com/mitosis.htm

II. Sexual Reproduction Sex cells - egg (female) and sperm (male) - must unite to produce offspring Two parents (male and female) Offspring are NOT identical to parents they share traits from both parents.

Labradoodle

III Fertilization The union of egg cell (female) and sperm cell (male). Also called gametes May be: External – occurs OUTSIDE the body of the female Fish, amphibians (water environment) many eggs/lower survival rate Internal – occurs INSIDE the body of the female. Reptiles, birds, mammals fewer eggs/higher survival rate

IV - How are sex cells made? MEIOSIS Sex Cells (aka GAMETES) only have half of the genetic material from the parent Human body cells 46 chromosomes Human Egg cell - 23 chromosomes Human Sperm - 23 chromosomes Egg + Sperm = 1 Zygote with 46 chromosomes which eventually becomes a BABY

MEIOSIS The name of cell division that results in SEX cells is MEIOSIS http://www.geneticsmadeeasy.com/preguntas/pregunta30.html

Mitosis vs. Meiosis Mitosis Has 1 division results in TWO identical “daughter cells” SAME # of chromosomes as the parent cell. Meiosis Has 2 divisions results in 4 SEX CELLS HALF the chromosomes of parent cell

Mitosis/Meiosis Mitosis is the process that aids in the production of body cells for growth and repair Meiosis is the process that aids in the production of sex cells for reproduction

Body Cells 1. Every cell in your body has 46 chromosomes (diploid). 2. You receive a set of 23 from your mother's egg and a matching set of 23 from your father's sperm (haploid). 3. These chromosomes are the genetic material inside nearly every cell of your body.

Sex Cells 1. Sex cells – made during meiosis, a cellular division process that is different than mitosis. 2. Meiosis – Produces new cells with half the usual number of chromosomes. a. When the sex cells are made, the chromosomes are copied once and the nucleus divides twice b. The resulting sperm and egg have half the number of chromosomes found in a normal body cell.

4 2 Significance Halved for fertilization Role Reproduction Body Cell Reproduction Sex Cell Reproduction Role Growth and Repair Reproduction Where process occurs Cells in all parts of body Gonads Number of chromosomes in resulting cells Same number as in parent cell Humans 46 Half the number as in parent cell Humans 23 Number of cells that result 2 4 Significance All information is passed on Halved for fertilization

Male Reproductive System Male Reproductive System – the main function of the male reproductive system is to produce and deliver sperm Testicle (testes) – pair of male gonads contained in small pouch called the scrotum produce sperm and testosterone Urethra - tube which carries semen and millions of sperm. It runs thru the penis outside of the body

Male Reproductive System

Female Reproductive System the main function is to produce ova (egg cells) and provide a safe place for the developing embryo (baby) 1. Ovary (Ovaries) – pair of female gonads located in the abdominal cavity close to the fallopian tubes. a. Produce eggs (release 1 mature OVUM per month) and secrete estrogen (female hormone) OVUM – the female gamete – 1 EGG 2. Uterus – a hollow pear shaped muscular sac Fallopian tubes lead to the uterus 3. Cervix muscular ring at the bottom of the uterus (dilates in labor) 4. Vagina (birth canal) – tube that connects the cervix to the outside of the body.

Female Reproductive System http://www.heumann.org/body.of.knowledge/m2/female.jpg