body systems and plants Flashcards
gas exchange
- process by which the gases oxygen and carbon dioxide are exchanged between cells of an organism and the environment
- occurs by diffusion across a plasma membrane
breathing
- in order to extract oxygen from the air, air must enter the gas exchange area of the body and diffuse into cells
- air is moved in and out of the lungs by movement of the ribs and diaphragm
- diffusion difference for oxygen traveling rom the alveolus to red blood ells is very short
exchange across whole body surface - aquatic
- small animal only
- large surface area to volume ratio
- body shapes are long and thin
e. g. earth worms and jelly wish
exchange across external gills
- gills can be damaged due to their delicate structure
exchange across internal gills
- water pass over the gills must be actively moving to maintain concentration gradient
- gills are protected from damage by being houses inside the animal
bird lung
- have high demand for oxygen
- metabolism is high and flight requires a lot of oxygen
- very efficient gas exchange system
- have air sacs to enable one way flow through lungs
bird lungs efficiency
- large surface area - many tiny air capillaries
- diffusion - short, thin walls
- moist - air capillaires are wet, conserve moisture
- maintaining a concentration gradient - air flows in one direction through the lungs regardless of inhaling or exhaling
why do fish suffocate
- when out of water fish gill filaments stick together
- reducing SA of gills
- gases are not exchanged as when in wtaer
- not enough O2 supply or CO2 removed
- poisoned by low pH enzymes reduce function
exchange at the end of fine tubes through the body
- air diffuses through a tubular network
- spiracles
- insects breathe through spiracles
- air enters spiracles allowing oxygen to travel along a network of tubes to reach cells
mammal lungs
- most efficient form of gas exchange in terrestrial environment
mammal lung efficiency
large surface area - many small alveoli
diffusion short - thin capillary walls
moist - wet lining of alveolus
maintaining concentration gradient - air is exhaled and replaced with fresh inhaled air
- blood returns to heart to get pumped around the body
diaphragm
- relaxed and loose is inhaled
- brought up is exhaled
digestive system
- the process when large complex molecule ae broken down into simple substances
- animals make energy using food and oxygen
teeth
carnivore - sharp ripping teeth - incisors, canines, premolar, moler herbivore - wide grinding teeth - premolar, molars omnivore - both kinds of teeth - incisors, canines, premolar, molar
digestive system - herbivore and omnivore
- long digestive system
- harder to digest cellulose
- bacteria in intestines help
carnivores digestive system
- short digestive system
- protein easier to digest then cellulose
ruminant
- chewing partly digested food a second time in order to soften it.
teeth - some have no upper incisors or canines
large foregut - stomach has 4 chambers (ruman, reticulum, omasum, abomasum)
foregut fermenter - very large stomach, small intestine e.g. sheep and cows
non-ruminant
handgun fermenter -small stomach and large intestine/colon
simple digestive system - sharp incisors and no canines, long gut with hind gut
e.g. humans horse rabbit
poultry
beak - no teeth can’t chew
crop - stores food
gizzard - crushes food using grit stones
vent - one opening for waste and reproduction
ingestion
- taking in of nutrients into mouth
adaptations - organisms choosing suitable food for ingestion - mouth parts assist in feeding behavior
- physical features that assist in catching food e.g. cheetah - speed
digestion
- chemical and mechanical breakdown of food into small molecules that can be absorbed
adaptations - structure/ shape and number of teeth
- structure of tract
- indicate the foods an animal can digest
absorption
- the taking up of digested molecules into the internal environment of the cells digestive tract
egestion
the removal of waste food materials from the body
digestion main roles
- ingestion
- digestion
- absorption
- egestion
carnivore
organisms that kills and eat animals e.g. fox
omnivore
organism that eats both living plants or parts of them e.g. humans
mechanical digestion
- when large pieces pf food are broken down into smaller parts through chewing or muscular movement in the stomach
- aim is to increase the surface area of food so it can be acted on by enzymes in chemical digestion
chemical digestion
when enzymes break down complex substances into their simplest form
e.g. carbs - glucose
ruman
- the first and largest section of the stomach
- solid feed is mixed and partially broken down
- the human contains millions of bacteria and other microbes that promote fermentation
circulatory system 4 main function
- transportation of water , oxygen and carbon dioxide
- distribution of nutrients and removal of wastes
- maintenance of body temperature
- circulation of hormones
small organisms CS
- arthropods e.g. insects and snails
- open circulatory system
- fluids circulation are not fully enclosed in blood vessels
- heart pops the lymph into large spaces and bathes the cells with nutrients and then re-enters the heart
animal transport
- size and shape of animals effects the ways nutrients and gases are transported to/from cells
small/flat animals CS
e. g. flat worms, jelly fish
- habitat - aquatic or high moisture region
- environement moves materials past cells
- large SA: vol ratio therefore substances diffuse in and out of their bodies fast
- no heart, blood vessels or blood
- limited by the need for a high moisture environment
large animals CS
- large and or metabolically active organisms
- e.g. fish, birds and mammals
- aquatic or terrestrial environments
- closed circulation - blood circulates inside network of blood vessels
- muscular heart pumps blood through blood vessels under pressure
2,3 or 4 chambered heart
fish Cs
- 2 chambered heart (atrium and ventricle)
- closed circulation
- single circulation
amphibians CS
3 chambered heart
- left atrium, right atrium and ventricle
- double circulation
4 chambers
- right and left side
- double circulation
- right side of the heart pumps blood to the lungs
- blood then returns to the left side and is piped to the rest of the body
- each side has 2 chambers atrium and ventricle
open vs closed system
define o - heart pumps into open cavity c - heart pumps into network of vessels heart o- more then 1 c-1 vessel o - none or few c - elaborate network pressure o - low pressure slow movement c - high pressure fast movement
arteries
- carry blood away from the heart
- blood under great pressure
- thick, more muscular walls
veins
- carry blood to the heart
- blood under less pressure
- thinner walls, less muscles
capillaries
- move blood between veins, arteries and cells
- low pressure
- thin walls, 1 cell thick
- huge surface area for exchange
water balance
plants use water to :
- keep cool
- photosynthesis and support other chemical reactions
- keeps cells firm and supported
- transport minerals up
water is:
- absorbed through hypertonic root hair cells
- transport up the stem by capillary action
- lost by transpiration from leaves
root hairs
- long, very thin, increase SA:Vol ratio
- hypertonic so osmosis moves water into the root hairs
stems and vascular bundles
- vascular bundle = xylem+phloem+cambium
xylem
- carries water and minerals up from the roots
- via capillary action
- wide hollow pipes
phloem
- carries sucrose up and down from the leaves
- companion cells and sieve cells are living
- narrow
- water from xylem moves into phloem via osmosis
cambium
- divides xylem and phloem
- making stem thicker and stronger
transpiration
- water evaporates from leaves while the stomata are open for the exchange of CO2 and O2 during photosynthesis
abiotic factors affecting transpiration
light intensity - more light increases transpiration, stimulates guard ells to take in water ad eon to allow CO2 to diffuse in for photosynthesis
temperature - hotter increases diffusion and transpiration, water evaporates quicker
humidity - high humidity reduces transpiration, when surrounding air is dry diffusion of water is faster, increasing diffusion gradient increases water loss
soil water - wet soil increases transpiration, plants can’t keep transpiring rapidly if water lost is not replaced
translocation
- transport of sugars and amino acids to all parts of the plant, this is rapid and requires energy
- sucrose is actively pumped from photosynthetic cells into sieve cells
- energy for this is from companion cells, sucrose moves into phloem
- draws water in from xylem, sucrose leaves the sieve cells tp be used by the plant for cellular respiration
adhesion
- water rises in the narrow vessels partly because water molecules are attached to the walls
cohesion
- water molecules are attached to each other and as water evaporates from the leaves columns of water are drawn up through the xylem vessel
ring barking tree
- removal of a strip of bark from circumference of tree
- woody plants have vascular bundles in outer ring
- removes phloem
- sugars can’t be carried down to roots, roots de due to lack of energy for respiration
water movement in plants
- water enters hypertonic root hairs
- water moves to xylem in the centre of the root
- water moves up xylem tubes
- water leaves xylem into the leaf moving into spongy layer by osmosis
- water evaporates into the spaces behind the stomata and diffuses into the air
leaf structure
- cuticle upper epidermis palisades layer spongy layer - xylem, phloem lower epidermis stomata and guard cells
upper epidermis
- layers of cells covered by waxy cuticle, prevents water loss
xylem leaf structure
- vascular tissue that transports photoysnthetic products out of leaves
guard cells
open and close stomata, control respiration
palisades layer
contain chloroplasts at top for maximum light absorption
spongy layer
- produce spot for gas exchange and large spaces for air and water vapor
xerophytes
live in deserts where water is scarce and evaporation is rapid
adaptations
- waxy cuticle, thick epidermis - reduces transpiration, water proof
- leaves small, shed leaves - store water, less SA for evaporation
- stomata on lower leaf - smaller SA for diffusion
- sunken stomata, hairs - keep humid air in stomata, reduces diffusion
- reversed stomatal rhythm, open at night - cooler, more humid, reduces diffusion
