BIO* - Biology BIO* M121 Lecture Notes - Lecture 19: Gametogenesis, Signal Transduction, Haplodiploidy
9 Jun 2020
School
Department
Course
Professor
Document Summary
Steroid hormones bind to receptors inside target cells and affect gene expression. These complexes then bind to hormone-response elements located upstream from the start of target genes. Amplification allows for a small amount of hormone to have a very large effect. Epinephrine"s signal is amplified at each of steps 3-6. Epinephrine activates an enzyme that catalyzes the formation of glucose from glycogen. Phosphorylase is activated when an enzyme adds a phosphate group to it. Animals have a diverse array of reproductive strategies. Organisms may be capable of asexual reproduction, sexual reproduction, or both. Humans males and females have different reproductive structures with different functions. Sex hormones play important roles in mammals. Development of the human fetus can be divided into three trimesters. Females are xx and males are xy (most mammals) Females are zw and males are zz (e. g. birds, butterflies) Males are developed from unfertilized eggs and are haploid. Females develop from fertilized eggs and are diploid (hymenopterans)
