Plant Reproduction: Sexual and Asexual

• Plant reproduction includes sexual and asexual reproduction along with key adaptations and terminology.
• Objectives include familiarization wiht plant reproduction and life cycles with groups of plants.
• Objectives also include explaining the mechanisms of alternation of generation.

Sexual Reproduction

• Sexual reproduction requires the fusion of male cells from pollen grains with female cells in the ovule.
• Advantages of sexual reproduction include the introduction of genetic mixing.
• Genetic mixing from sexual reproduction leads to increased variability in a population.
• Disadvantages of sexual reproduction include the fusion of egg & sperm cells which may be limited to a specific season.
• Sexual reproduction is slower than asexual reproduction.

Asexual Reproduction

• Asexual reproduction is natural cloning.
• Parts of a plant like leaves, stems, or roots can produce new roots and become independent plants.
• Asexual reproduction is fast and does not require a mate.
• Asexual reproduction is beneficial for plants to compete for scarce resources.
• All individuals produced via asexual reproduction are genetically identical.

Terminology

• Haploid cells have a single set of chromosomes.
• Diploid cells have two sets of chromosomes.
• Mitosis produces two genetically identical cells.
• Meiosis is reduction division, producing four haploid reproductive cells.

Plant Adaptations to Land

• Most plant groups are adapted to dry and cold habitats through structural modification.
• Stomata are present across plant epidermal surfaces.
• Plants have waterproof cuticles.
• Xylem and pholem are vascular tissues.

From Haploid to Dipload Dominance:

• Algae and nonvascular plants dominants the haploid body
• Most modern plants dominants the diploid body

Alternation of Generations

• Plants have a double life cycle with 2 distinct forms.
• Sporophytes are diploid and produce haploid spores via meiosis.
• Gametophytes are haploid and produce gametes via mitosis.
• Complex sporophytes can retain, nourish, and protect new generations throughout seasons

Seed Plants (Angiosperms) Life Cycle

• Microspores develop into pollen grains containing sperm-producing male gametophytes.
• Megaspores become female gametophytes (with eggs) inside ovules.
• Seeds are mature ovules.
• Parts of the ovule become nutritive tissue and a seed coat to protect the embryo sporophyte.

Conifers Life Cycle

• Pollen germinates and grows a pollen tube into the egg to allow sperm to fertilize the egg
• Conifers are wind-pollenated plants
• Chance allows these pollens to land on the scales of the female cones

Explore plant reproduction, covering both sexual and asexual methods. Understand the advantages and disadvantages of each, including genetic mixing in sexual reproduction and the speed of asexual reproduction. Learn about plant adaptations and life cycles.