30 terms

Biology: Plant Stuff

Structures in plants and other plant-related stuff you should probably know.
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Simple leaf
a leaf that is made up of one entire blade
Compound leaf
a leaf with many leaflets as its blade
Cuticle
the part of the leaf that protects the epidermis and creates a waterproof barrier
Upper epidermis
the part of the leaf above the palisades layer that prevents the loss of water
Palisades layer (mesophyll)
the part of the leaf that absorbs light with chloroplasts for photosynthesis; it is tighter and more dense than the spongy layer
Spongy layer (mesophyll)
the part of the leaf where most photosynthesis occurs; it is "spongy" and less dense due to the gasses that pass in and out of the leaf as a result of photosynthesis and respiration
Xylem
the vascular tissue in the spongy layer that transports water throughout the plant
Phloem
the vascular tissue in the spongy layer that transports food throughout the plant
Lower epidermis
the part of the leaf below the spongy layer that has the stomata and guard cells
Stoma
the opening in the lower epidermis through which gases (oxygen, carbon dioxide, water vapor) pass through; controled by the two guard cells surrounding it
Guard cells
the cells surrounding each stoma that open and close the stomata
Root
the part of the plant below ground that takes in water and nutrients and pass them along to the stem; also anchors plant in the ground; food is often stored in them as well
Epidermis (root)
the outermost part of the root that protects the root
Cortex
the part of the root for storing food; they are irregularly shaped cells in between the epidermis and the endodermis
Endodermis
the part of the root that protects the xylem and phloem
Primary root
the root that is the first to develop from a germinating seed
Secondary root
the roots that branch off of the primary root
Root hairs
the "very fine hair-like structures" jutting out from the epidermis (root); each is one cell with a cell wall made of cellulose
Fibrous root system
a root system consisting of many small roots; secondary roots can be as big as the primary root
Ex. Grass
Taproot system
a root system in which the primary root is the largest in the root system; when the primary root grows quickly
Ex. Carrot
Tropism
a growth response to stimuli
Geotropism
growth towards gravity
Phototropism
growth towards light
Thigmotropism
response to touch
Hydrotropism
response to water
Positive tropism
growth towards a stimulus
Negative tropism
growth away from a stimulus
Stem
transports materials between the roots and the leaves; provides support for other plant parts
Woody stems
stems that are made of wood and are more firm; plants with these stems tend to live longer than two years
Herbaceous stems
stems that are generally softer, juicier and thinner than woody stems; plants with these stems usually have short life span (one or two years)