BISC 132 Lecture Notes - Lecture 6: Dinos, Xeroderma, Sequential Hermaphroditism
Document Summary
Segmented worms: each segment has muscle, ganglion (nerve), reproductive organs, allows regeneration. Closed circulatory system: have blood and blood vessels. Named for clitellum: part of reproductive system, harboring deposited sperm/eggs and young worms. Leech saliva has anesthetic and anticoagulant properties. Larvae hatch in stomach, burrow to intestine: can migrate to heart/muscle/brain. Forward genetics: mutate organisms randomly and search for a specific phenotype; identify mutated gene. Reverse genetics: disrupt a gene and observe phenotype. Cephalothorax, abdomen: exoskeleton of chitin and protein. Vulnerable during and after molt: jointed appendages for better motion control. Modified appendages: legs, wings, mouthparts, antennae: open circulatory system, nervous system. Motor functions controlled by different ganglia along body: respiratory system. Allow gas (o2) to diffuse to internal cells. Spiders important predators of insects: many make liquid-protein webs, all are venomous. Most have compound eyes for large field of vision. Same basic mouthparts modified for diverse functions. Many undergo metamorphosis: complete (like butterflies, simple (series of molts like roaches)