*Exam #3 Study Guide Bio 1111

Exam #3

Chordata

notochord, dorsal hollow nerve cord, pharyngeal slits, and post-anal tail

Lancelets

simple chordates that show all four chordate traits throughout life and are filter feeders

Tunicates

chordates that show chordate traits mainly in the larval stage

Vertebrates

chordates with a backbone and skull for protection and movement

Chondrichthyans

cartilaginous fish such as sharks and rays with flexible skeletons for speed

Actinopterygii

ray-finned fish with an operculum covering the gills and a swim bladder for buoyancy

Operculum

bony flap that covers and protects the gills in fish

Swim bladder

internal gas-filled organ that helps fish control buoyanc

Sarcopterygii

lobe-finned fish with fleshy fins that evolved into limbs in tetrapods

Tetrapod

fourr-limbed vertebrate adapted for life on land

Amniotes

group including reptiles, birds, and mammals that have amniotic eggs for land life

Amphibians

vertebrates that need water for reproduction and use moist skin for gas exchange

Reptiles

vertebrates with scaly skin that prevents water loss and are mostly ectothermic

Birds

endothermic vertebrates with feathers, lightweight bones, and high metabolism for flight

Mammals

endothermic vertebrates with hair and mammary glands

Monotremes

mammals that lay eggs such as the platypus

Marsupials

mammals whose young develop in a pouch after birth

Eutherians

placental mammals whose young develop fully inside the uterus

Oviparous

animals that lay eggs outside the body

Ovoviviparous

animals whose eggs develop inside the mother and hatch before birth

Viviparous

animals whose embryos develop inside the mother and receive nutrients directly

Cells → Tissues → Organs → Organ system

levels of biological organization in animals

Epithelial tissue

covers body surfaces and lines organs providing protection, absorption, and secretion

Connective tissue

binds and supports other tissues including bone, blood, cartilage, and fat

Muscle tissue

responsible for movement and includes skeletal, smooth, and cardiac types

Nervous tissue

receives, processes, and transmits information through neurons

Endotherms

animals that maintain a constant internal body temperature using metabolic heat

Ectotherms

animals that depend on external heat sources to regulate body temperature

Radiation

heat transfer through electromagnetic waves

Evaporation

heat loss when liquid on the skin turns to vapor

Convection

heat transfer by the movement of air or water across the body surface

Conduction

direct heat transfer between objects in contact

Countercurrent exchange

flow of fluids in opposite directions to conserve heat or gases

Metabolic rate

amount of energy used by an organism per unit of time

BMR (Basal Metabolic Rate)

resting metabolism of an endotherm under neutral conditions

SMR (Standard Metabolic Rate)

resting metabolism of an ectotherm under specific temperature conditions

Torpor

shortt-term reduction in metabolism and activity to save energy

Hibernation

long-term reduction in metabolism and temperature during cold seasons

Poikilotherms

animals whose body temperature changes with the environment

Homeotherms

animals that maintain a stable internal body temperature

Herbivores

animals that eat mainly plants

Carnivores

animals that eat mainly other animals

Omnivores

animals that eat both plants and animals

Essential nutrients

nutrients that cannot be synthesized by the body and must come from food

Essential amino acids

amino acids that the body cannot produce and must get from diet

Essential fatty acids

fatty acids that must be obtained from food

Vitamins

organic compounds required in small amounts for metabolism

Minerals

inorganic elements needed for body structure and function

Intracellular digestion

digestion that occurs inside cells

Extracellular digestion

digestion that occurs in a cavity or tract outside of cells

Gastrovascular cavity

simple digestive compartment with one opening for food and waste

Alimentary canal

complete digestive tract with a mouth and an anus

Oral cavity

where ingestion and mechanical digestion begin

Pharynx

throat region connecting the mouth to the esophagus

Esophagus

tube that carries food from the mouth to the stomach

Stomach

organ that secretes acid and enzymes to break down food

Small intestine

site where most digestion and nutrient absorption occurs

Duodenum

first section of the small intestine where most chemical digestion happens

Large intestine

absorbs water and forms feces

Colon

main part of the large intestine that reabsorbs water

Cecum

pouch connected to the junction of the small and large intestine

Pancreas

produces digestive enzymes and bicarbonate to neutralize stomach acid

Liver

produces bile to help digest fats

Bile

substance that breaks fats into smaller droplets for digestion

Gallbladder

stores and releases bile into the small intestine

Gastric juice

acidic mixture containing enzymes that break down food in the stomach

Enzymes

proteins that speed up chemical reactions including digestion

Pepsin/Pepsinogen

pepsinogen is converted to pepsin in acid to digest proteins

Chemical digestion in the human digestive system

process of enzymes breaking food into absorbable molecules

Absorption in the small intestine

movement of nutrients into blood through villi and microvilli

Villi

small fingerlike projections that increase surface area for absorption

Microvilli

tiny projections on villi that further increase surface area

Regulation of digestion

controlled by hormones and nerves to coordinate enzyme release and movement

Glucose homeostasis

maintaining steady blood glucose levels using hormones

Insulin

hormone that lowers blood glucose by promoting cellular uptake

Glucagon

hormone that raises blood glucose by promoting glycogen breakdown

Diabetes

disorder caused by failure of insulin regulation leading to high blood sugar

Open circulatory system

system where fluid called hemolymph bathes organs directly

Hemolymph

fluid that acts like blood in open circulatory systems

Closed circulatory system

system where blood is confined to vessels

Blood

fluid that transports gases, nutrients, and wastes in closed systems

Cardiovascular system

system of heart and blood vessels that circulates blood throughout the body

Single circulation

blood passes through the heart once during each full circuit as in fish

Double circulation

blood passes through the heart twice per circuit separating oxygen-rich and oxygen-poor blood

Arteries

vessels that carry blood away from the heart

Arterioles

small arteries that regulate blood flow into capillaries

Capillaries

tiny vessels where gas and nutrient exchange occurs

Capillary beds

networks of capillaries within tissues

Venules

small vessels that collect blood from capillaries

Veins

vessels that return blood to the heart and often contain valves

Heart

muscular organ that pumps blood through the circulatory system

Ventricle

chamber that pumps blood out of the heart

Atrium

chamber that receives blood returning to the heart

Lymphatic system

network that collects fluid from tissues and returns it to the blood

Lymph

fluid that circulates through the lymphatic system

Erythrocytes

red blood cells that carry oxygen using hemoglobin

Leukocytes

white blood cells that fight infection

Tracheal system

network of air tubes in insects that deliver oxygen directly to tissues

Lungs

organs used for gas exchange in vertebrates

Larynx

voice box and part of the airway above the trachea