Gas exchange Flashcards
How do single celled organisms absorb and release energy?
through diffusion
What are the two main adaptations gas exchange surfaces have?
they have a large surface area
they are thin which provide a short diffusion pathway
What is each gill in fish made from and what does it provide?
made from lots od plates called gill filaments which give a a large surface area for exchange of gases
What are gill filaments corverd in and what does it provide?
lots of tiny structures called lamellae which increase the surface area
What do lamellae have?
lots of blood capillaries and a thin surface layer of cells to speed up diffusion
Describe the counter current system in fish.
blood flows through the lamellae in one direction water flos in the opposite direction. this maintains a concentration gradiennt between the water and the blood. the concentration of oxygen in the water is always higher than that of the blood, so as much oxygen diffuses into the blood as possible
What do insects use for gas exchange?
microscopic pipes called tracheae
Where does air move into the tracheae?
throught the pores on the surface called spiracles
Where does oxygen go after going to the tracheaes?
to the tracheoles, and then they diffuse directly into the respiring cells
How are the mesophyll cells adapted to there function?
they have a large surface area
What do guard cells do?
they control the opening and closing of the stomata
What do insects do if they lose to much water?
they close there spiracles using muscles they have a waterproof cuticle and tiny hairs around their spiracles both of which reduce evaporation
What are plants called that are adapted to live in the warm dry and windy habitats?
xerophytic
What are some adaptations for xerophytic plants?
stomata sunk in pits that trap moist air reducing the concetration gradient of water between the leaf and the air
a layer of hair in the epidermis that traps moist
air
curled leaves with the stomata inside protecting from windy conditions
reduced the number of stomata
wazy waterproof cuticles on leaves
