Plants

 Asexual reproduction: one living organism involved.  Offspring identical to parent.  Sexual reproduction: requires one male and one female parent.  Offspring looks like parents but is genetically different.

 Conifers and flowering plants: produce cones, flowers and seeds.  Algae, mosses and ferns: produce spores.

 Does not involve meiosis or fertilization.  One parent.  Used by single-celled organisms such as Archaea, bacteria, and protists.  Plants use roots, stems or leaves to reproduce asexually.

 An advantage of asexual reproduction is that an organism can reproduce by itself and it can occur rapidly. Asexual reproduction can lead to rapid population growth of a species.  A disadvantage of asexual reproduction is that only clones are reproduced – there is no genetic variation. An organism would not be able to adapt and evolve to a changing environment.

 One forest = one individual

 Binary fission: one cell divides to form two identical cells. It duplicates its genetic material and then divides. Each new cell has its own complete copy of the parent’s genetic information.  Budding: part of the parent develops into a new organism. The new organism then pinches off from the parent and lives independently. The new organism is genetically identical to its parent.  Fragmentation: the body of the parent breaks into two distinct pieces, each can produce an offspring.

 Increased genetic diversity of the offspring.  Characterized by two processes:  Meiosis  Fertilization: combination of two gametes (sex cells)  During meiosis, chromosomes usually cross over = genetic recombination.  Primary method of reproduction for the vast majority of visible organisms, including almost all animals and plants.  Plants reproduce sexually: through flowers, cones or seeds.

 Sexual reproduction has the advantage of providing lots of variation within a species, helping it to survive when the environment changes.  The main disadvantage is that this process takes a lot of energy and time. This means that they can only produce small populations.

 A seed contains all the requirements needed to produce a new plant:  The embryo: small immature plant  The cotyledon: food reserves  The seed coat: protective cover

 Gymnosperm (conifer): “naked seed”  The seed only has the seed coat to protect it.  Angiosperm (flowering plant): “enclosed seed”  The seed has the seed coat as well as a second cover (pod, shell or pulp).  Pod (beans)  Shell (nuts)  Pulp (fruits)

 Reproduction in spore-producing plants:  No production of seeds!  Spores: cells that contain complete genetic material – can become an immature plant without fertilization.  Males spores become plants that produce spermatozoa and female spores become plants that produce ovules. Then comes fertilization.  Reproduction in conifers:  Male cones contain male gametes  Female cones contain female gametes  Seeds develop in female cones once the ovules are fertilized.  Reproduction in flowering plants:  Pollination and Fertilization  Seed development  Seed dispersal

 Flowers can either have male reproductive organs (stamens), female reproduction organs (pistils or carpels) and often a flower has both.

Anther: where pollen is produced and stored Filament: supports the anther Pollen: contain male gametes (spermatozoa)

Stigma: sticky surface that captures the pollen. Style: supports the stigma Ovary: contains female gametes (ovules) Ovules: female gametes

 Pollination leads to fertilization (zygote or fertilized egg).  Fertilization: male and female gametes combine.  Pollen must land on the stigma in order to fertilize the flower = pollination.  Self-pollination: pollen transferred to the pistil of the same flower.  Cross-pollination: pollen transferred to the pistil of a different flower through wind or insects.

 1 st stage of development: spermatozoon (singular of spermatozoa) enters the ovule = fertilization.  2 nd stage of development: Cell divides into many cells that specialize themselves into different structures for different functions.

 Seed dispersal: main mode or style of dispersing seeds is through fruits.  5 main agents of seed dispersal:  Animals, water, wind, the plant itself and humans (sowing seeds).

 Seed, seedling (young plant), adult plant, flower, fruit and back to seed.