Reasons for Cell Division
- Cell division is required for:
- a) growth
- b) repair & replacement of damaged parts
- c) reproduction of the species
In Cell Division Copies of the DNA Must Be Sent to Both New Cells
- Since the instructions for making cell parts are encoded in the DNA, each new cell must get a complete set of the DNA molecules
- This requires that the DNA be copied (replicated, duplicated) before cell division
Genetic Blueprints for Cells Are Organized Into Chromosomes
- The plans for making cells are coded in DNA
Sex is Very Costly
- Large amounts of energy required to find a mate and do the mating: specialized structures and behavior required
- Intimate contact provides route for infection by parasites (AIDS, syphillis, etc.)
- Genetic costs: in sex you pass on only half your genes to your children
- Males are an expensive luxury- in most species they contribute little to rearing offspring
But There are Some Advantages
- More genetic diversity: more potential for survival of species when environmental conditions change
- Shuffling of genes in meiosis
- Crossing-over in meiosis
This is a preview of WHY SEX? -SEXUAL REPRODUCTION-TECHNICAL POINT OF VIEW FOR DISCUSSION.
Read the full post (949 words, 3 images, estimated 3:48 mins reading time)
