Angiosperms Flowering plants that reproduce sexually through their

Angiosperms Flowering plants that reproduce sexually through their flowers Seeds are protected within fruit Most widespread of all land plants

Angiosperm Adaptations to Life on Land Alternation of generations Vascular tissue Xylem tissue has vessel element cells and fiber cells instead of tracheid cells Vessel Arranged end to end and forming continuous tubes that are better at carrying water than tracheids but not as good for giving supporting Fiber element cells evolved from tracheid cells also evolved from the tracheid cell. Have thick lignified walls and are specialized for supporting

Angiosperm Adaptations to Life on Land Leaves Resist drying out due to thick waxy covering (cuticle) Stomata Roots Stems

Gymnosperm Adaptations to Life on Land Seeds Reproduce free from water Protect and nourish embryo until environmental conditions are favourable Pollen grains are dust-like particles carried by wind, insects, birds, animals

Angiosperm Subclasses Two subclasses of angiosperms: 1. 2. Monocotyledonae (monocots) Dicotyledonae (dicots)

Angiosperm Subclasses Monocots: angiosperms whose seeds have one cotyledon Dicots: angiosperms whose seeds have two cotyledons Cotyledons: leaves of the embryo Filled with food First leaves to carry out photosynthesis

Monocot & Dicot Characteristics Monocots Dicots Leaves Veins in leaves are parallel Veins in leaves form a branching network Flower parts in threes or multiples of three Flower parts in four or fives or multiples of four or five Vascular bundles in stem Vascular bundles are scattered Vascular bundles are arranged in a cross section of a stem in a ring in a cross section of a stem Vascular bundles in root Bundles of xylem and phloem A single mass of xylem forms alternate with one another in a an “X” in the center of the circle root: Phloem bundles are located between the arms of the “X” Stem thickness Stems of most monocots do Stems can grow thicker from not grow thicker from year to year

Monocot & Dicot Characteristics

Angiosperm Reproduction Reproduce sexually through their flowers in a process that involves pollination

Angiosperm Reproduction Pollination is the transfer of pollen from one flowering plant to another Plants pollinated via wind have small, plain flowers with little or no smell Ex. corn, wheat, grass Vector pollination – pollination by animals Mutualistic relationship Animals get food (nectar or pollen) Plants get pollinated

Angiosperm Reproduction

Angiosperm Reproduction

Angiosperm Reproduction

Female Reproductive Structures Pistil: contains the stigma, the style, and the ovule(s) within the ovary Stigma: captures and traps the pollen with a sticky or hairy substance Style: allows the pollen tube to travel down to the ovule Ovary: encloses and surrounds the ovule Contains one or more ovules for double fertilization to take place The ovule contains the female gametophyte (the egg (N) and the polar nuclei (N+N)

Male Reproductive Structures Stamen: contains the anther and the filament Anther: undergoes meiosis to produce the pollen grain (male gametophyte) Filament: supports the anther

Other Flower Parts Receptacle: the base where the petals, ovary, and sepals are attached Sepals: they are green and they enclose and protect the developing flower Petals: they are brightly coloured and scented to attract insects, bats, and birds

Pollination Pollen is transferred by insects, bats, birds, or wind from the anther to the sticky stigma and germinates producing a pollen tube The two sperm nuclei travel down the tube to the opening of the ovule

Fertilization Two sperm nuclei enter the ovule opening Double fertilization takes place One sperm nuclei (N) fuses with the polar nuclei (N+N) producing an endosperm (provides nutrients for the developing embryo) The other sperm nuclei (N) fuses with the egg (N) producing a zygote (2 N) which developsinto an embryo in a seed Ovary thickens to become a fruit The ovule toughens to produce the seed coat

Coevolution of Animals and Flowers Initially, this relationship must have evolved accidentally However, the coevolutionary relationship strengthened because it was beneficial to the survival of both plants and animals Ex. bees remember the color, shape and odor of a flower it finds food on very clearly the bee will continue to look for those flowers on its way to the food (pollen) the bee might pollinate the flower with pollen from the last flower it visited this ensures the survival of the plant Ex. flowers that are pollinated by moths are very fragrant (we use them for perfumes) moths can't see color but have an excellent sense of smell Ex. flowers pollinated by flies smell like rotting meat! (flies are looking for places to lay egg)

Seed Dispersal Seed dispersal the process of distributing seeds away from parent plants Why do seeds need dispersal? If seeds fall to the ground beneath the parent plant instead of being dispersed they will compete with one another and with the parent plant for sunlight, water, and nutrients competition will reduce the chances of survival for the growing seeds seed dispersal also enables plants to colonize new environments

Seed Dispersal Seeds can be dispersed by Wind Getting caught in the fur of animals Tasty and nutritious fruit get eaten, the fleshy part is digested by the animal but the seeds are not Seeds are excreted from the animal in a new environment with fertilizer

Seed Dispersal Have you ever wondered why unripe fruits are green and have bitter taste? Inside unripe fruit the seeds are still maturing Unripe fruits are bitter tasting to try to keep animals from eating them if they are eaten too soon, the immature seeds will not be able to grow Unripe fruit is green so that they are camouflaged with the plant and are not easily found by animals