Unit 3: Plants Flashcards
meristems
only places where growth occurs within plants- stem, branch and root tips. meristems create undifferentiated and unspecialized cells that make new cells through mitosis
includes cork cambium- produces bark and increases the width
vascular cambium- produces new vascular tissue
in stems it increases in length
specialized tissues
- meristematic tissue
- surface tissue- epidermal tissue
- storage cells- large vacuoles that store the products of photosynthesis. in the leaves they are full of chloroplasts. pith is the centre of the stem that stores things
- support tissue- supports plants
- vascular tissue- transports nutrients
vascular tissue
transports nutrients throughout the plant. xylem -transports water. phloem- transports sugars
types of flowering plants
monocots which have scattered vascular bundles and dicots which have vascular bundles in rings
plantae
multicellular eukaryotes, cell wall made of cellulose, photosynthetic, develop from multicellular embryos
diploid vs haploid
diploid- sporophyte generation
haploid gametophyte generation (sperm and egg cells)
plants need
sunlight
water and materials
gas exchange
movement of water and nutrients
evolution of plants
plants evolved from green algae into mosses and mosses evolved the derived characteristic; vascular tissue. which evolved into ferns, that developed the derived characteristic seeds which gave way to coniferous plants and the seed eventually become enclosed which made flowering plants.
mosses
no vascular tissue
no seeds
moss and ferns
flowers
have enclosed seeds
seeds
gymnosperm- which have naked seeds and angiosperm which bear seeds in layers of protective tissue
seed plants do not require water because..
they have flowers and cones
the sperm is transferred by pollination
The embryos are protected
conifers
very common gymnosperm plants so they have naked seeds. conifer leaves are so good at surviving because the leaves on needles have a small surface area so water can’t evaporate, they have a waxy layer so water can’t escape and gas exchange cavities are below the surface
angiosperm
have enclosed seeds and flowers which are the reproductive organs (ovaries). after flowers are pollinated they turn into fruits and animals consume them carrying seeds far distances.
monocots
single cotyledon (first leaf produced by the plant) parallel veins floral parts in multiples of 3 vascular bundles scattered fibrous roots
dicots
doble cotyledon (First two leafs produced by plant) branched veins Floral parts in multiples of 4 or 5 vascular bundles are in rings taproot
monocot stem
encloses a series of vascular bundles dispersed randomly around the stem. the phloem is on the outside and the xylem faces the inside and has larger cells
dicot stems
vascular bundles arranged and organized in like a ringlike pattern. the pith is the centre of the stem on the outside of the vascular bundles is the cortex. again the xylem is facing the centre and the phloem is facing the cortex. between the phloem and xylem is vascular cambium which produces more vascular tissue
apical meristem
occurs at the end of the root/ stem/ branches produces unspecialized, undifferentiated cells and increases in the length. PRIMARY GROWTH
secondary growth ( dicots)
Increases in width. Cork cambium produces cork. Vascular cambium becomes continues between vascular bundles (between phloem and xylem). Produces secondary phloem and the outter phloem is crushed.
secondary xylem
vascular cambium produces more phloem increasing the width of stem. the primary phloem which was created first is pushed towards the centre and becomes plugged with resin- won’t work and is known as the heartwood. While the secondary phloem is produced and is functional it is called the sapwood
pith
is the centre
layers of a tree starting from the outside
cork, cork cambium, secondary phloem, vascular cambium, secondary xylem( sapwood), heartwood( older xylem), pith.
spring xylem cells and fall xylem cells
spring- larger than fall cells because they get a lot of nutrients they are lighter too.
fall- not as many nutrients so the cells are smaller thicker and darker
these two rings (lighter and darker) represent one year of growth for a tree and indicate the conditions the tree grew in
formation of vascular cambium
young stems are produced through primary growth- primary xylem and phloem. secondary growth occurs at th cork cambium(producing cork) and the vascular cambium which is located between the xylem and phloem. the meristematic tissue forms producing new vascular tissue
bark
all tissue outside of vascular cambium including phloem cork cambium and the cork itself. cork cambium surrounds the cortex. cork is dead. cork protects. cork prevents water loss
female reproductive organ in flower
PISTIL includes- stigma- which is the uppermost part of the pistil and receives pollen grains during pollination.
style- the sticky top part of the pistil directly above the ovary
ovary- produces ovules it is the female reproductive organ at the base of the pistil
male reproductive organ in flower
stamen includes-anther- tip of the flowers stamen that contains pollen
Filament- stem of the anther and supports it
petal
colourful leafy structure that attracts insects
sepal
small leaves under the petals
root is composed of
outer layer- epidermis. Inner part- composed of cortex and within the cortex are dark cells called starch granolas. centre- surrounded by endodermis and within that is the xylem which is in an x shape and little bundles of phloem around it.
pollination
when pollen reaches pistil(female sex organ)
flower
sexual ( male and female) organ of a plant and attracts insects for pollination.
fruit
fruit is food for the seed. surrounds the seed and aids in the dispersal of the seeds
fertilization
sperm fuses with egg.
seed
embryo of new plant
seed dispersal
animals wind and water and example of wind is a dandelion or tumbleweed and example of water is coconuts and an example of animals is bees they pollinate everything
food in embryo
is actually the endosperm which supplies the embryo nutrients and eventually develops into the cotyledon ( first leaf)
germination
seed sprouts in favourable conditions
double fertilization
when pollen grain on stigma creates pollen tube and goes down into pistil and eventually to ovaries there are two sperm nuclei, one which fertilizes the egg and one which fuses with two polar nuclei to create a triploid cell which will grow to become the nutrient rich endosperm and it will be in the seed and supply the embryo with nutrients.
egg-yellow
sperm-red
polar nuclei-blue
what is a seed composed of
surrounded by seed coat, embryo attached to side and endosperm around the embryo.
cuticle
uppermost layer of a leaf- on surface is waxy and prevents water loss
upper epidermis
transparent cells that don’t have many if not any chloroplasts.
palisade cells
contain majority of the chloroplasts and they are parallel and vertical to each other. and just under the upper epidermis
veins
in leafs are composed of the xylem which is on the upper epidermis side and the phloem they are the circles in the spongy mesophyll
spongy mesophyll
spongy cells in leaf which contain air pockets and are below the palisade layer.and just above the lower epidermis.
lower epidermis
bottom of the leaf. doesn’t contain chloroplasts. contains stoma that is surrounded by guard cells that regulate the amount of air that goes into the air pockets for gas exchange.
apical meristem
located at the tip of a root, stem, that increase the primary growth of the plant (length)
cotyledon
first leaves of the seedling monocot-1 dicot-2
polar nuclei
two haploid nuclei in the centre of the embryo same that fuse with the sperm nuclei creating the endosperm that supplies embryo with nutrients
