Animal Diversity Exam Three PDF

Summary

This document provides an overview of animal diversity, focusing on various classes of animals, including characteristics like skin permeability, reproduction methods, and conservation challenges. It contains details about amphibians, reptiles, and mammals.

Full Transcript

Diversity of Animals Vertebrates: Osteichthyes - Bony fish! o Make up 50% of all vertebrates - Swim bladder is derived from the ancestral lung. - Operculum and swim bladder are important! Amphibians - Anura (frogs), Urodela (salamanders), Apoda (caecilians) - All...

Diversity of Animals Vertebrates: Osteichthyes - Bony fish! o Make up 50% of all vertebrates - Swim bladder is derived from the ancestral lung. - Operculum and swim bladder are important! Amphibians - Anura (frogs), Urodela (salamanders), Apoda (caecilians) - All amphibians have water permeable skin (so skin is VERY important for water-salt balance) o Some amphibians use their skin explicity for breathing and gas exchange - Most require water for reproduction o External fertilization o Many have conspicious metamorphosis - Frogs o They’re going through it. Amniotes - Unlike frogs, amniotes can reproduce independently of an aquatic environment. o Four extraembryonic membranes allow for greater independence from water. ▪ Yolk sack – nutrients ▪ Amnion – contains embryo ▪ Allantois – forms blood and waste extraction with the mother ▪ Chorion – contains everything mentioned above Reptiles - Non avian: Turtles, lizards, crocodiles - Avian: Birds! - Skin covered in a keratin based covering (normally scales, but feathers in birds) o Obtain O2 through their lungs - Most are ectothermic --> use environment to regulate temperature o Birds are endothermic --> use their own internal body to maintain their body temperature. - Testudines o Turtles, terrapins, and tortoises o Bony shells covered by keratin plates; keratinized jaws o Aquatic and terrestrial o All oviparous (lay eggs), TSD is common (temperature sex determination – the temp an embryo develops in the egg determines if it becomes a male or a female) o The ancestral condition here is just having a sternum ▪ Ribs are broad, flat, and unified - Lepidosauria o Squamates (lizards and snakes) and tuatara (lizard like group that only have one currently living species) ▪ All have a three chambered heart ▪ Terrestrial, arboreal, aquatic ▪ Ovi-, ovovivi-, and viviparous o Lizards vs snakes ▪ Shedding ▪ Eyelids True snakes don’t have eyelids while most lizards do ▪ External open hearing ▪ Flexibility of jaw/skull - Archosauria o Crocodilians, birds, and dinosaurs o They have a four chambered heart o Crocodiles diverged long before birds diverged from dinosaurs - Crocodilia o 25 species of allgators, caiman, crocodiles, and gharial o Complete secondary pallate o All oviparous and TSD o Maternal care Conservation Challenges: Non-avain Reptiles - Over 20% of reptiles are threatened-habitat loss primary driver - Data deficient species made up 20% of the assessments - Turtles and crocodiles are the most in trouble o Aquatic species are especially threatened Reptiles - Aves - Evolved from two-legged dinosaurs called theropods - Archaeopteryx is the most primitive known bird 9150 million years old) o Feathered wings and claws o Teeth and long tail with many vertebrae Adaptations for Flight - Feathers – modified scales o Origianlly for thermo regulation o Later used for gliding, then powered flight - Reduced body weight o Fully keratinized beak o Pneumatic bones Conservation Challenges: Birds - Among vertebrates, birds are the lowest proportion of threatened species o They don’t have to worry about terrestrial predators - Unregulated harvest of songbirds - Habitat destruction for waterfowl - Introduced predators: Domestic cats and snakes Mammals - Hair o Covers mammals in some capacity o Endothermic o Deals with thermoregulation - Mammary glands o Dedicated lactation units that are critical for giving offspring an early leg-up in life - Heterodont and diphyodont teeth o Meaning having different teeth with different functions - Sebaceous and sudoriferous glands Mammals - Monotremes - Oviparous (egg laying) - Lack nipples, but secrete milk onto abdomen o Lost all teeth --> elongated snout - Duck-billed platypus and echidna Mammals - Marsupials - Kangaroos, wallabies, koalas - Brief gestation, complete development in marsupia while nursing. - Dominant in Australia Mammals - Eutherians - Complex/extensive placenta - Gestation usually correlated with size - Altricial (can’t do anything on their own) to precocious (they can do everything moments after birth) young Conservation Challenges: Mammals - Most familiar megafuna conservation issues - Majority of recent conservation successes are with mammals - Abundance of resources available relative to less marketable groups o Australian Mammal Conservation ▪ 10% of native extinct with 200 years ▪ 20% currently threatened to extinction ▪ Examples: Tasmanian tiger The Body’s Systems - Homeostasis and thermoregulation o Negative feedback: a regulatory mechanism that reduces fluctuations in a system's output by feeding back information about the output itself (maintaining and balance) ▪ Set point ▪ Response carried out by effectors ▪ Opposes stimulus to hold the set point ▪ Examples: thermoregulation, pH, blood pressure, blood glucose, etc... Like walking in from a cold room outside into the sun, your body will want to cool down and make you sweat. o Positive Feedback: a process that increases or magnifies an output or process ▪ Amplified response ▪ Short term fix ▪ Examples: fight or flight, breast-feeding, giving birth, blood clotting, etc... ▪ - Osmoregulation (urinary system) o Maintained by negative feedbacks o The balance between water and salt in the body ▪ The interaction between the excretory system to maintain healthy level sof water and salt in your blood o Found in kidneys, ureters, urinary bladder, urethra ▪ Urine production and excretion is good for ridding hte body of nitrogenous waste, excess salts, and toxins/drugs and water ▪ Concentration regulated by hormones o If you have too much salt, your blood cells could become hypertonic or hypotonic o Done via diffusion (salt goes where there’s lower concentrations of water --> osmosis) - Digestive system o Ingestion, digestion, absorption, and then elimination o Macronutrients: carbs (simple sugars), proteins (amino acids), and fats (lipids) ▪ Anatomy: Oral cavity – matistcation (chewing) and saliva (starch) Esophagus – transports food via peristalsis (a series of involuntary muscle contractions that move food and other substances through the body) Stomach – begin protein digestion (gastric juice) Small intestine – most chemical digestion (pancreatic juice); absorption Large intestine – absorption of water and salts (waste) Rectum – stores feces Anus – terminal opening ▪ Accessory Organs: Salivary glands – break down starch Liver o Produces bile (fat emulsification) o Detoxifies absorbed substances from diet o Repackages nutreints Gallbladder – stores bile Pancreas – secretes digestive enzymes and pH buffer o Essential nutrients ▪ Must be obtained in diet 8 of the 20 amino acids Fatty acids: several omega-3 and –6 Vitamins: organic compounds; coenzymes Minerals: inorganic compounds; structural, electrolyte balance; enzyme cofactors - Circulation and respiratory system o Gas exchange: O2 in, CO2 out o Transport of substances ▪ Gases, nutrients, hormones, nitrogenous waste, antibodies and immune cells, thermoregulation, etc... o Respiratory Anatomy: ▪ Nasal/oral cavity --> pharynx --> trachea (contains the cartilage rings) --> bronchi --> bronchioles --> alveoli (gas exchange) --> diaphragm (the divide) o Circulatory Anatomy: ▪ Pulmonary circuit: heart --> lungs --> heart (gas exchange of deoxygenated blood from the heart to the lungs to send it back to the heart oxygenated for the rest of the body aka the systemic circuit) ▪ Systemic circuit: heart --> body --> heart ▪ Arteries: away from the heart ▪ Capillaries: exchange ▪ Veins: back to the heart o Cardiac Cycle ▪ Steps Step 1: Starts at rest --> blood rushes in from sinoatrial Step 2: Your atria contract and force blood into relaxed ventricles Step 3: Pushing the blood out the heart to either the system or pulmonary circuit ▪ Sinoatrial node (blood rushes in through this node) ▪ Valves ▪ Diastole (120/80) ▪ Systole – pulse - Movement from musculoskeletal system o Skeletal system: ▪ Support and movement Attachment points Joints – wherever bones meet o Synovial – very flexible (in fingres, knees, elbows..) o Cartilaginous – cushions between vertebrae o Fibrous – inflexible (in skull) ▪ Protection ▪ Mineral and lipid storage ▪ Blood cell production ▪ Axial (head, lungs, spine) vs appendicular (limbs like arms, legs, and pelvis) o Muscles ▪ Skeletal muscle – most dense and striated (voluntary) ▪ Smooth muscle – digestive system and movement of substances through the body (involuntary) (ex: peristalsis) ▪ Cardiac muscle – propels blood (involuntary) - Internal coordination from endocrine and neural signaling o Endocrine signaling ▪ Stimulates responses over seconds or days (super fast or slow) ▪ Source: endocrine glands and cells Mechanism: hormones Target: any cell with a receptor for that hormone o Neural signaling ▪ Stimulates responses in milliseconds ▪ Source: neurons Mechanism: electric impulses and neurotransmitters at synapses (junction between nerve cells) Target: post synaptic cell; neuron, muscle or gland o Nervous system ▪ Central nervous system (CNS) Brain and spinal cord Integrates sensory information Initiates outgoing motor (voluntary) and autonomic (automatic/involuntary) responses ▪ Peripheral nervous system (PNS) Sensory information: receptors to CNS Motor and autonomic systems: CNS to effectors ▪ Autonomic nervous system (ANS) Sympathetic NS: triggers fight or flight o Mobilizes stored energy (glucose) o Delivers more oxygen and glucose to muscles Parasympathetic NS: triggers the rest o Restores energy reserves o Repair/recover after strenuous activity Enteric division: digestive system o Peristalsis and secretions

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