GEN-3000 Lecture 5: Genetics_Chapter 5
Document Summary
Female produces two different gametes, half with z chromosome, the other half with w (found in birds, moths, some amphibians, and some fish) Temperature-dependent: ex. alligator- warm temperature during embryonic development produces males, cool=females. Bridges, a student of morgan"s found this occurred too frequently to be mutation, hypothesized that x chromosomes fails to separate. Remember: genes are located on chromosomes and chromosomes are substrate for gene segregation. Femlae grasshopper cells had 1 more chromosome than males. X and y separate into different sperm cells, while egg cells all get a single x. At meiosis, half sperm receive x, other half get no sex chromosomes. Heterogametic sex- the sex at produces two different gametes. Homogametic sex- the sex that produces identical genes. No obvious difference in chromosomes (i. e. no sex chromosome) Sexual reproduction: formation of offspring that are genetically distinct form parent. Sex: defined by phenotype of individual (not genotype) Monoecious: has both female and male reproductive structures "one house"
