Gaseous exchange and transport systems Flashcards
Respiratory surface of insect
spiracles(openings along S of body), branch into tracheaue (connects int envir. to external enviro and allows exchange of gases)
Respiratory surface of fish
gills made of gill fillaments(increase SA). Water passed through mouth ontop of gilll filaments. Blood flows in opp direction in gills to ensure maximum gas exchange
Respiratory surface of Frog
exchanges gaes by lungs or
skin (cutaneous respiration, skin must be moist)
Mammals
exchange gases by lungs (consist of subdividing branches that end in alveoli, point where gas exchange occurs)
Why do mulitcellular organisms need transport systems?
They grow large so longer distance for Oxygen and nutrients to move where needed. So, they need extensive and efficient transport systems
Xylem
transports water and other minerals moves in upward direction hollow dead tubes made of lignin very strong (suppors plant) needs no cellular energy
Phloem
transports sugars (mainly sucrose)
made of living cells
cambiam cells give energy to tube cells. Their end walls ahve pores for food t be transported from cell to cell (in form of dissolved sugars)
Stomata
tiny pores on leaf surface made by 2 guard cells
allows carbon dioxide to moive in and oxygen ot move out
water vapour passes out from leaf to atmosphere through stomata
Lenticells
pores found of S of stems, roots and branches
takes in oxygen from air
Root hair cells
give large SA for absorption of water and minerals
Does wind increase amount of water moving through plant?
Yes as well as temp, low humidity.
They don’t have nervous system to do this
Why do some animals need more efficient circ systems?
Because they are large / more active
How does an OPEN Circulatory system work?
Hemolymph leaves heart in short branched arteries that open into large spaces
Hemolymph bathes cells, then return to heart directly or through short veins
What are the advantages of an OPEN Circulatory system?
Direct exchange of materials between Hemolymph and cells
No diffusion barrier
What are the disadvantages of an OPEN Circulatory system?
little control over Hemolymph to body regions
no mechanism to increase/decrease flow to specific part of an organ
What are consequences of an OPEN Circulatory system?
found in smaller/ inactive animals
most molluscs have them (excpet cephalopods-squid, octopus)
Insects have adapted to its limitations by tracheal system for Oxygen supply
How does a CLOSED Circulatory system work?
Blood in completely closed system, vessels form closed loop, blood usually moved by some for of pumping (heart)
Vessels branch into smaller tubes that pentrate tissue cells
All vertebrates have them, incl worm (which is slower, smaller but has one)
What are the advantages of a closed circulatory system?
Has control over where blood goes in dif regions
The muscular walls of vessels constrict and dilate to vary flow through certain vessels.
High blood pressure, circulation can be vigorous.
What is mitsosis?
The division of nucelus resulting in new body cells. daughter cells identical to parent
What are daughter cells made for?
Growth and repair
What is cytokinesis?
Division of cytoplasm and organelles it contains
Where does mitosis occur in plants?
meristems: buds, cambium, pericycle(at tips of roots & stems)
Where does mitosis occur in animals?
special tissues:basal layer of skin, bone marrow, cells lining digestive tract, bone & liver cells
Where does mitosis occur in insects?
in epidermal cells during metamorphis
Where does mitosis occur in trees?
In roots and shoot tips and cambium
How does a tree grow?
IN 2 stages! In height
& in girth FOREVER (cambium under bark)
What different organelles contain DNA?
The nucleus, and Mitochondria, chloroplasts need it for many proteins & enzymes needed for their function
Why do chloroplasts and mitochondria have DNA?
Before they were autotrophic( bacteria like unicellular orgs absorbed into organisms
What is the theory for why chlorplasts and mitochondria have DNA?
The endosymbiotic theory
Why do they use radioisotopes?
Help understand organ processes in orgs
