Plant Overview
and
Reproduction
Pre-AP Biology
What Is a Plant?
• Members of the kingdom Plantae
• Plants are multicellular eukaryotes
• Plants have cell walls made of
cellulose.
• Plants develop from multicellular
embryos and carry out
photosynthesis using the green
pigments chlorophyll a and b
2
Overview of the Plant Kingdom
• Botanists divide the plant
kingdom into four groups
based on three important
features:
1. Water conducting tissues
2. Seeds
3. Flowers
3
4
5
The Plant Life Cycle
• Characterized by alternation
of generations:
the two generations are the haploid
(N) gametophyte, or gameteproducing plant, and the diploid (2N)
sporophyte, or spore-producing plant.
6
7
Monocots and Dicots
• Monocots and dicots are
named for the number of seed
leaves, or cotyledons, in the
plant embryo. Monocots have
one seed leaf, and dicots
have two seed leafs
8
9
Reproduction of Seed Plants
Chapters 24
Life Cycle of Gymnosperms
• Reproduction in gymnosperms
takes place in cones
• Male cones produce – pollen
grains
• Female cones produce –
ovules
Flowers and Fruits
• Angiosperms have unique
reproductive organs known as
flowers.
Q: Why are flowers evolutionary
adaptations?
A: they attract animals that
pollinate them
14
15
Structure of Flowers
• Flowers are reproductive
organs that are composed of 4
kinds of specialized leaves
Sepals
• Enclose the
bud before
it opens,
leaf-like
Petals
• Brightly colored, attract insects
to flower
Stamen
• Male reproductive
structure of flower,
made of 2 parts
• Filament – long,
thin, stalk that
supports the anther
• Anther – makes
pollen grains
Anther
Filament
Anther + Filament = Stamen
Pistil
• Female reproductive structure,
made of 3 parts
Stigma
• where pollen
grains land,
sticky
Style
• Connects stigma to ovary
Style
Ovary
• swollen base of
the pistil where
ovules are
formed
• Flowers contain ovaries, which
surround and protect the
seeds
• After pollination, the ovary
develops into a fruit, which
protects the seed and aids in
its dispersal.
28
Fruit
• Ripened ovary, thick wall of
tissue that surrounds the seed
29
Pollen
Pollen Grain
• Contains the male gamete
31
Pollination
• The transfer of pollen from the
male gametophyte to the
female gametophyte
32
Seeds
• An embryo of a plant that is
encased in a protective
covering and surrounded by a
food supply
33
Embryo
• Early development stage of a
sporophyte plant
• The seed’s food supply
provides nutrients to the
embryo as it grows
34
Seed Coat
• Surrounds and protects the
embryo and keeps the
contents of the seed from
drying out
• Can be specialized for
dispersal
35
36
Pollination
• Most gymnosperms (some
angiosperms) are wind pollinated
• Most angiosperms are pollinated
by animals
• Insect pollination beneficial to
insects and other animals:
provides them with food
• Plants also benefit: this method of
pollination is more efficient
Seed Dispersal
• Animals
• Wind and water
Ultraviolet Flowers
http://www.naturfotograf.com/UV_flowers_list.html