Gymnosperms and Angiosperms
Biology 112
Presentation 4
Gymnosperms




Include pines, spruce, juniper, fir and other cone
bearing plants.
Thin, needle-like leaves are a special adaptation
to hot-dry summers and cold winters, with
moderate rainfall.
Needles retain moisture because of their thick
waxy cuticle.
Their roots extend over a wide surface area, as
opposed to penetrating deep into the soil.
Angiosperms



Comprise more than all the other plant
division combined (over 250 000 known.)
Many angiosperms and insects have
become completely inter-dependant.
This process of joint evolution of two or
more species is called coevolution.
Common Characteristics of
Flowers

Stamen is the male part of the flower. It
consists of:
A thin stalk called a filament
 An anther where pollen is formed


The carpel, or pistil is the female part of the
flower. It consists of:
The stigma – sticky part which pollen lands and grows
 The style – slender stalk pollen grains travel to ovary
 The ovary – contains ovule

More Common Characteristics of
Flowers

Sepals – small green leaf-like structures
that surround the carpel and stamen

Petals – colorful part that attracts
pollinators

Nectary – small swelling at base of each
petal
Complete, or Incomplete Flowers

Complete flowers contain carpels, stamens,
petals, and sepals.



I.e. lilies, tomatoes, etc.
Incomplete flowers are missing at least one
of these structures.
In most species the petals die off after
fertilization.
Reproduction


Refer to your handout for life cycle.
Do worksheet.
Monocots

Monocotyledons is an angiosperm whose
seeds have only one cotyledon or seed leaf.
Vascular bundles distributed throughout stem
 Veins parallel
 Flowers in 3s or multiples of 3

Dicots

Dicotyledon is an angiosperm whose seeds
have two cotyledons or seeds leaves.
Vascular bundles arranged in ring
 Veins netlike
 Flowers in multiples of 4s or 5s
