CONIFERS

2 kinds of cones

MALE VS. FEMALE CONES

FemaleSeed conesimmature

MalePollen cones

Femaleimmature

Male

Mature Immature

“NAKED” AND “COVERED”

REPRODUCTION

Scales

Male cones produce male gametophytes called pollen grain

Female cones (seed cone) produce female gametophytes called ovules (eggs)

Embryo – same idea as zygote (egg+sperm)

Conifer Reproduction

Unfertilized ovule

seed coat

Egg(n)

Female gametophyte

(n)

In this example we are using a pine cone

Unfertilized ovule

Male gametophyte(pollen grain)

(n)

Femalegametophyte (n)

Dischargedsperm nucleus (n)

Micropyle

Fertilization initiates the transformation of the ovule into a seed

Conifer Reproduction

Seed coat

Food supply

Embryo (2n)Inside the seed

(new sporophyte)

Compared to a single-celled spore,

a seed is much more resistant and

complex

Conifer Reproduction

RISE TO THE ANGIOSPERMS

Seed plants appeared ~360 mya

with the rise of the Gymnosperms

Flowering plants (Angiosperms)

– the other surviving lineage – appeared ~200

million years later