Plants!
A plant = a multicellular eukaryote that has a cell
wall made of cellulose
They develop multicellular embryos
They carry out photosynthesis using
chlorophyll
Plants have 2 different
kinds of reproductive cells;
gametes and spores
Plants take up water/nutrients
in their roots and make food in
their leaves
Most leaves have thick
flattened sections
called blades to help
collect sunlight
There are 2 main types of roots: taproots and fibrous roots
With a taproot – the
primary root grows long
and thick (oak/hickory
trees and carrots)
Fibrous roots can have
extensive branch systems
(grasses)
Plants started out in water and had
to adapt to living on land
The first plants evolved from an
organism much like the multicellular
green algae living today
The plant kingdom is divided into 4 groups
based on three important features: water
conditioning tissues, seeds, and flowers
Bryophytes have life cycles that depends on
water for reproduction – this keeps the these
plants relatively small
They include mosses, liverworts, and hornworts
Humans can use peat (thick
deposits of moss) as fuels
Peat moss can also be
used in gardening
Seedless vascular plants evolved
after bryophytes and were the first
plants to have vascular tissue
They include club mosses,
horsetails, and ferns
Vascular tissues is a transportation system to move
water, nutrients, and food through the plant
Xylem helps move
water up from the roots
Phloem transports
nutrients and food
Seed plants are the most dominant form of plants
They are divided into 2 groups:
gymnosperms (their seed are on the
surface of cones) and angiosperms
(flowering plants that protect their seeds)
Seeded plants became the dominant plant because they
are able to reproduce without water
Angiosperms can be separated into
2 classes: monocots or dicots
They are named for the number of seed leaves
(cotyledons) in the plant embryo
Monocots have one seed leaf
Dicots have 2 seed leaves
Other difference between the two
include distribution of vascular
tissue, stems, roots and leaves and
the number of petals per flower
Plants have adaptations in order to respond to their
environment
Plants have hormones in order to
grow and respond
A hormone = a chemical substance
that controls a plant’s pattern of
growth and development, and the
plant’s response to environmental
conditions
Auxins stimulate cell elongation
(the plant getting taller)
Auxins are responsible
for phototropism – a
plants tendency to grow
towards the light
Auxins are also responsible
for gravitropism – a plants
response to the force of
gravity
Thigmotropism isn’t caused by auxin but is similar to
photo/gravitropism – it is a plants response to being
touched
Some plants that are over
handled can end up with
stunted growth
Cytokinins do several things,
including delaying the aging
of leaves and helps in the
early stages of plant growth
Gibberellins produce a dramatic
increase in size, particularly in
the stem and fruit
Ethylene helps fruit ripen
Some plant responses don’t involve growth
Some plants will close their leaves
when touched (sensitive plant)
Some plants have sensory cells
that allow a quick response (venus
fly traps)
Many plants have adaptations to
the environment they are in
Many aquatic plants have tissues
with large air-filled spaces
through which oxygen can diffuse
Plants that live in salt water
(mangroves) are salt tolerant –
they have special adaptations to
get rid of the extra salt they take in
Desert plants have extensive
roots, reduced leaves, and thick
stems so they can store what
water they get
Plants that have specialized
features for obtaining nutrients
include carnivorous plants and
parasites
Pitcher plants drown insects
in their pitcher-shaped leaves
that hold rain water and
digestive enzymes
Sundews trap insects with
sticky secretions
Mistletoe is a parasitic
plant that gets its food
from the trees it grows on
The Venus fly trap has sensory
hairs that when touched tell the
plant to snap closed
Many plants defend themselves against
insect attack by manufacturing compounds
that can have effects, including death and an
interrupted reproduction style, against the
animal eating it
Monocot vs. Dicot
Dicot
Monocot vs. Dicot
Dicot
Monocot vs. Dicot
Monocot
Monocot vs. Dicot
Dicot
Monocot vs. Dicot
Dicot
Monocot vs. Dicot
Monocot
Monocot vs. Dicot
Monocot
Monocot vs. Dicot
Dicot
Monocot vs. Dicot
Monocot
Monocot vs. Dicot
Dicot