Test 3 Flashcards
requirements for living organisms
acquire resources, eliminate waste, exchange metabolic gasses, homeostasis, control function, development, reproduce
What makes an animal an animal?
eukaryotic, multi-cellular, aerobic, heterotrophic. Usually mobile, complex, and engage in sexual reproduction. cells divide by cleavage and carbs stored as glycogen or fat.
When did multicellular organisms arise on earth?
about 700 mil years ago. Life has been on earth 3 1/2 billion years
multi-cellularity limitations
must form complex mechanisms for resource and waste exchange with their environment.
Why do animals urinate?
unlike plants, animals make copious metabolic waste and must eliminate it through different methods like urination.
What causes animals to have different sizes and shapes
environmental conditions. waste/resource exchange, physics for swimming, burrowing, or flight, competition, physical environment such as thin air or cold temperatures, etc.
interstitial fluid
water-based solution that surrounds organ systems and cells and provides place for transport.
organism hierarchical organization
cell, tissue, organ, organ system, organism
structure=
function!
4 major tissue types
connective tissue, epithelial tissue, muscle tissue, and nervous tissue.
epithelial tissue
covers body surfaces and lines internal organs. base of apical cells attached to basement membrane. can be squamous, cuboidal, or columnar.
Connective tissues
cells held in a fibrous or fluid extra-cellular matrix. Subtypes include: loose, adipose, fibrous, cartilage, bone, and blood
loose connective tissue (ct)
bind and shape
adipose ct
store fat
fibrous ct
strong connections
cartilage ct
cushions
bone
support system; movement
blood
connect tissues to resources
muscle tissue
composed of cells that can contract. 3 types: skeletal, cardiac, smooth
skeletal tissue
enable movement, attached to bones by tendons. voluntary
cardiac tissue
forms the heart, involuntary
smooth/visceral
not striated, surrounds digestive tract and other organs, involuntary
nervous tissue
transmits messages throughout body with electrical impulses
organs
composed of two or more types of tissues organized into a functional unit.
body cavities
fluid filled spaces that cushion and suspend organs. Often layers of connective tissue and sheets of muscle
11 major organ systems
digestive, circulatory, respiratory, immune, excretory, nervous, muscular, reproductive, endocrine, skeletal, integumentary
bioenergetics
flow of energy through an animal. controlled by energy sources vs. energy uses. metabolic rates vary based on activity, size, and homeostatic + thermoregulation strategies.
metabolic rate increases as
body size decreases
homeostasis
maintenance of constant internal conditions; usually via negative feedback
conformers
do not maintain steady internal conditions; internal values vary with external conditons
thermoregulation
2 main strategies: ectothermy and endothermy.
cost and benefits to ectothermy
activity and endurance limited but low energy cost
why was development of endothermy an important adaptation to the colonization of land
moving on land requires more energy and land temp fluctuates more than water temp, so endothermy is ideal for terrestrial survival
strategies to adjust rate of heat exchange
constriction or dilation of blood vessels, raising fur or feathers, fat accumulation, countercurrent heat exchange, behaviors
countercurrent exchange
arterial blood is warmer and warms adjacent venous blood in extremities
behaviors for thermoregulation
moving to shade/sun or into/out of water. restricting activity to day/night, migrating, social behavior to share heat
adjusting metabolic rate
increasing/decreasing muscular activity, acclimation, torpor
Acclimation
adjust to temp changes throughout seasons by changing enzyme quantity and type and altering lipids to keep membranes fluid
torpor
reaction to predictable temp and food supply fluctuations by entering state of reduced metabolism (hibernation, etc.)
the cellular metabolism of __________ will produce nitrogenous waste
proteins, nucleic acids, ATP
what percent of basal metabolic rate is used for osmoregulation in most environments
5%
Marine animal osmoregulation
water will move out of animal, so they must drink lots of water and excrete little urine. gain solutes due to diffusion gradient, which is filtered out by kidney (C, Mg, sulfates) or transport proteins on skin (Na, Cl) most marine invertebrates are osmoconformers and are isotonic to seawater. Osmoconformers actively regulate solute concentrations to maintain homeostasis.
freshwater animal osmoregulation
water will enter animal through osmosis and must excrete large volumes of urine. many maintain lower cytoplasm solute concentrations than marine regulators to help reduce solute gradient. Urine loss depletes solutes, so active transport at gills replenishes some solutes. Some animals like salmon can switch environments and strategies.
extreme dehydration can cause some animals to become
dormant
water balance in terrestrial animals
terrestrial animals have adaptations to reduce water loss. Solutes are regulated primarily by the excretory system.
terrestrial adaptations to water loss
waxy cuticle, shells and scales, layers of dead skin cells, fur to insulate, eating wet food, retaining metabolic water, small respiratory openings.
sodium/potassium pump
metabolic energy is used to transport (2) K+ into the cell and (3) Na+ out, producing an electrochemical gradient. The cell interior becomes more negative than outside.