40+ Flashcards
convergent evolution
reflects different species’ adaptations to a similar environmental challenge
Exchange rate is proportional to the organisms’ ______
surface area to volume ratio
______ the interchange of O2 and CO2 between an organism and its environment,
gas exchange
open systems
Blood is not contained in blood vessels
• Nutrient rich blood “open” in the body cavity
• a heart pumps fluid through open-ended vessels to bathe tissue cells directly.
closed systems
Blood contained in blood vessels
• a heart pumps blood, which travels through arteries to capillaries to veins and back to the heart.
Open circulatory system in which fluid called ______ is circulated into the spaces surrounding the tissues and organs
hemolymph
Gas exchange in spiders occurs in respiratory organs called
book lungs
Most modern cheliceriforms are_____ , which include spiders,
scorpions, ticks, and mites
arachnids
Close circulatory system gas exchange occurs in three stages:
- Oxygen intake (eg. Breathing with lungs, or water over gills)
- transport of gases by the circulatory system, and
- exchange of gases with body cells: Body tissues take up O2 from the blood and release CO2 to the blood.
A fish’s two- chambered heart pumps blood in a
single circulation.
Land vertebrates have _____ with a _____ and a ______
double circulation; pulmonary; systemic circuit.
Amphibians and many reptiles have_____ hearts
three- chambered
Birds and mammals have _____ hearts
four-chambered
thermoregulation
Process by which animals maintain an internal temperature within a tolerable range
_____ animals generate heat by metabolism
• More energetically costly
• Eg. Birds and mammals
endothermic
______ animals gain heat from external sources
• Typically tolerate a greater variation in temperature range
• Eg. most invertebrates, fishes, amphibians, and non-avian reptiles
ectothermic
The body temperature of a _____ varies with its environment, while that of a _____ is relatively constant
poikilotherm; homeotherm
Five general adaptations help animals thermoregulate:
– Insulation – Circulatory adaptations – Cooling by evaporative heat loss – Behavioral responses – Adjusting metabolic heat production
Vasodilation
blood flow in the skin increases, facilitating heat loss
Vasoconstriction
blood flow in the skin decreases, lowering heat loss
______ blood is warmed via heat transfer
Countercurrent exchange
_____ determines how much food it needs and is related to the animal’s size, activity, and environment.
bioenergetics
The amount of energy an animal uses in a unit of time is called its _____
metabolic rate
Body size influences _____
metabolic rate
Metabolic rate per gram is _____ related to body size among similar animals
inversely
anatomy
biological form
regulator
if an animal uses internal mechanisms to control internal change in face of external fluctuation
conformer
if an animal allows its internal condition to change accordance with external changes
the body tissue that consists largely of material located outside of cells is
connective tissue
which of the following would increase the rate of heat exchange between an animal and its environment
wind blowing across the body surface
consider the energy budgets for a human, an elephant, a penguin, a mouse and a snake. The ____ would have the highest total annual energy expenditure, and the _____ would have the highest energy expenditure per unit mass.
elephant; mouse
compared with a smaller cell, a larger cell of the same shape has
less surface area per unit of volume
an animals inputs of energy and materials would exceed its outputs
if it is growing and increasing its mass
you are studying a large tropical reptile that has high and relatively stable body temperature. how do you determine whether this animal is an endotherm or ectotherm?
you subject this reptile to various temperatures in the lab and find that its body temperature and metabolic rate change with the ambient temperature. you conclude it is an ectotherm.
which of the following animals uses the largest percentage of its energy budget for homeostatic regulation?
desert bird
diffusion
small molecules (O2 and Co2) in and around cells diffuse, which is random thermal motion
what is the circulatory fluid in open circulatory systems?
hemolymph
who has closed circulatory systems?
annelids (earthworms), cephalopods (squid, octopus) and all vertebrates
who has single circulation?
sharks, rays and bony fishes
what does gas exchange do?
– provides O2 for cellular respiration and – removes its waste product, CO2.
insects have a _____ for gas exchange
tracheal system
Metabolic rate is roughly proportional to body mass to the
three-quarter power (m3/4).
which of the following respiratory systems is not closely associated with a blood supply?
tracheal system of an insect
blood returning to the mammalian heart in a pulmonary vein drains first into the
left atrium
pulse is a direct measure of
heart rate
when you hold your breath, which of the following blood gas changes first leads to the urge to breathe?
rising CO2
one feature that amphibians and humans have in common is
the number of circuits for circulation
if a molecule of CO2 released into the blood in your left toe is exhaled from your nose, it must pass through all of the following except
the pulmonary vein
compared with the interstitial fluid that bathes muscle cells, blood reaching these cells in arterioles has a
higher Po2
active predators have _____ where as clams have an _____
closed systems; open system- they are filter feeders and don’t move
Insects use _____ that opens to atmosphere
spiracles
Smaller animals have a _____ surface to volume ratio so they lose heat faster
higher
Poikilotherm
an organism that cannot regulate its body temperature except by behavioral means such as basking or burrowing.
countercurrent exchange
blood is warmed via heat transfer
homeotherm
an organism that maintains its body temperature at a constant level, usually above that of the environment, by its metabolic activity.
Endothermic
animals generate heat by metabolism
More energetically costly
Birds and mammals
Ectothermic
animals gain heat from external sources
Typically tolerate a greater variation in temperature range
most invertebrates, fishes, amphibians, and nonavian
reptiles
Describe counter current exchange as it relates to heat exchange in thermoregulation. Give an example.
countercurrent heat exchanger is an arrangement of blood vessels in which heat flows from warmer to cooler blood, usually reducing heat loss.
Some animals use body insulation and evaporative mechanisms, such as sweating and panting, in body temperature regulation.
In the leg of a wading bird, the artery that runs down the leg carries warm blood from the body. The artery is positioned right alongside a vein that carries cold blood up from the foot. The descending, warm blood passes much of its heat to the ascending, cold blood by conduction. This means that less heat will be lost in the foot due to the reduced temperature difference between the cooled blood and the surroundings and that the blood moving back into the body’s core will be relatively warm, keeping the core from getting cold.
Describe counter current exchange in regards to gas exchange. Give an example.
Fish gills use a design called ‘countercurrent oxygen exchange’ to maximize the amount of oxygen that their blood can pick up. They achieve this by maximizing the amount of time their blood is exposed to water that has a higher oxygen level, even as the blood takes on more oxygen. Countercurrent oxygen exchange (shown in the figure above) means the blood flows through the gills in the opposite direction as the water flowing over the gills. This flow pattern ensures that as the blood progresses through the gills and gains oxygen from the water, it encounters increasingly fresh water with a higher oxygen concentration that is able to continuously offload oxygen into the blood.
Explain why highly folded internal surfaces are found in the body systems of complex multi-cellular animals?
In a large organism, diffusion is no longer sufficient. This is because:
the centre of the organism may be a long way from the surface, so it would take too long for substances to diffuse all that way;
the surface area to volume ratio is much smaller - that Is, It has a small amount of surface area compared to its total volume.
Large organisms solve these difficulties in two ways:
they have transport systems that carry substances by mass flow from one part of the body to another, rather than relying solely on diffusion;
they increase the surface area of parts of the body involved in exchange with the environment, for example by having thin, flat leaves or by having a highly folded gas exchange surface.
Explain the difference between open/closed circulatory systems. Provide an example of each.
Closed circulatory systems have the blood closed at all times within vessels of different size and wall thickness. In this type of system, blood is pumped by a heart through vessels, and does not normally fill body cavities. The open circulatory system is common to molluscs and arthropods.
osmoregulation
processes by which animals control solute concentrations and balance water gain and loss
osmoconformer
to be isosmotic with its surroundings
osmoregulator
to control internal osmolarity independent of that of the external environment
What is a sea star at -4 degrees in the deep sea?
Ectothermic; homoeotherm
a fish with internal (500 mOsl) is placed in a fluid of 700 mOsl. explain the osmoregulation
by pumping out salts to keep tissues at 500 mOs/l
marine iguanas feed on saltwater algae. which do they have that land iguanas do not?
nasal salt glands to excrete salt
clasper
claspers are an external appendage found on male sharks, skates, and rays that are designed to deliver sperm inside of a female.
countercurrent exchange for O2 transfer involves which process?
diffusion
temperature difference between arterial and venous blood near gooses body:
allows the goose to minimize heat loss to the environment – countercurrent exchange
what is adaptive advantage of a complete digestive tract?
It allows organization into specialized compartments
osmoregulation mechanisms in freshwater fish:
salt uptake in gills and water excretion in urine
if a hermaphrodite self fertilizes, will the offspring be identical to the parent?
No meiosis ensures unique combination of genes
whats an advantage of internal fertilization?
Prevents drying out of gametes
what would happen if your air had an abnormally high level of CO2?
Breathing rate increases
