BIO205H5 Lecture : Lecture #4 Notes
Document Summary
Slide3: life history: is an organism"s lifetime pattern of growth, development, and reproduction. involves adaptations ( physiological, morphological, adaptations to environment etc) an organisms decisions are going to be a balance between the costs and benefits. Slide 5: sexual reproduction: fusion of haploid egg and sperm to form diploid zygote. major source of genetic variation due to the recombination of chromosomes during gamete production asexual reproduction produces offspring without fusion of egg and gamete. parthenogenesis: aphids organisms that rely on heavily on asexual reproduction can revert to sexual reproduction. maybe unable to adapt to a change in environmental conditions benefits have to outweigh the costs. parents only contribute one half of their genes. expense of reproduction not equally shared between parents. Slide3: hermaphroditic: organisms possess both male and female organs. increased survival of young and parents" genes. to increase fitness by producing more offspring. Two or more mates ( pair bonds exist)
