Apply Concepts Pollination is a process that occurs only in seed plants. What process in seedless plants is analogous to pollination Review Describe how fertilization takes place in a gymnosperm Classify Make a table with two columns labeled haploid and diploid and assign each of the following structures from the pine life cycle to the appropriate column: Pollen tube, Seed cone, Embryo, Ovule, Seedling

Ch 22 Introduction to Plants 22.3 Seed Plants

The Importance of Seeds Adaptations of seeds Plants reproduce without open water Transfer of sperm by pollination Protection of embryos in seeds.

Seed Plant embryo and a food supply encased in a protective covering Living plant within a seed is diploid and represents the sporophyte phase.

Male gametophytes and the female gametophytes grow and mature directly within the sporophyte Gymnosperms Bear seeds directly on the scales of cones Angiosperms Bear seeds in flowers inside a layer of tissue that protects the seed.

Pollen Grains Contains entire male gametophyte Carried to the female reproductive structure by wind or animals Pollination Transfer of pollen from the male reproductive structure to the female reproductive structure.

Embryo begins to grow under right conditions Zygote contained within a seed grows into a tiny plant- the sporophyte embryo Embryo begins to grow under right conditions Uses nutrients stored in the seed until it can carry out photosynthesis on its own Seed coat Surrounds and protects the embryo and keeps the contents of the seed from drying out.

Seed cones produce female gametophytes Female gametophytes develop in two ovules at base of scale.

Pollen cones produce pollen grains, which make up the entire male gametophyte stage One haploid nuclei will divide later to produce two sperm nuclei.

Development Inside Seeds Pollen tube Structure containing two haploid sperm nuclei.

Development Inside Seeds Pollen grain lands ovule Splits open and begins to grow a pollen tube Reaches the female gametophyte One sperm nucleus disintegrates Other fertilizes the egg.

Fertilization produces a diploid zygote Grows into an embryo.

Seed is an encased embryo that is ready to be scattered by the wind and grow into a plant.

Reproduction in conifers occurs in cones from the mature sporophyte plant.