biology quiz 3
暂无描述。系统推荐的高质量记忆内容，适合每天坚持背诵学习。
卡片预览 (24 张)
Organisms respond to environmental factors called _______
stimuli
Plants have control systems called _______ which allow them to respond to changes in the environment.
Tropism
Tropism is the ______ mechanism a plant has in response to an external stimuli.
growth
plants can respond to stimuli by: • stoma _____ and ______ • branches grow • leaves drop off • flowers bloom
stoma open and closes
What is phototropism?
the growth of a plant towards the light
how does phototropism help plants?
helps plant maximize the amount of light they absorb through leaves.
more photosynthesis = …
fuels further plant growth.
which part of the plant shows positive/negative phototropism (grow towards/away the light)
Leaves and stems show positive phototropism (towards) and roots show negative phototropism (away).
What is the effect of auxin?
Auxin causes cells on the shades side of the stem to grow longer than the cells on the lighted side.
What is gravitropism?
A plant’s growth response to the force of gravity.
which part of the plant shows positive/negative gravitropism (grow downwards/upwards)
Roots show positive gravitropism (grow downwards) and stems show negative gravitropism (grow upwards).
What are nastic movements?
Reaction to touch (ex. venus fly traps)
What are xylem and phloem vessels?
a system of vessels that transport water, minerals, and sugar throughout the plant.
Where are xylem and phloem vessels found?
theyre found in leaves, roots, and stems.
Xylem vessels transport what from the soil to the leaves?
water and dissolved minerals
Xylem vessels are made up of _____ cells. form hollow tubes consisting of only cell walls. linked end to end, forming long continuous tubes.
dead
Water transported by xylem vessels is used for _______ and prevents wilting
photosynthesis
Phloem vessels transport ______ produced during photosynthesis.
sugars
Phloem vessels are made up of ________ joined end to end.
living cells
The cell walls in phloem vessels are ________ (contain tiny holes) allowing them to exchange materials with neighbouring cells.
porous
Sugary sap flows ____ the phloem vessels by passing through pores
down
Water and minerals enter a plant from the…
roots
At the core if the roots are the ______ and _____, surrounded by other cells.
xylem and phloem
most water uptake happens at the tip of the root by..
osmosis