Structure and Function of Living Organisms Plant Systems

Leaves Flowers Stem Fruit/Seeds Roots

Functions of Roots 1. Anchor the plant 2. Absorption of water and minerals 3. Storage of food

Types of Roots -- Fibrous

Types of Roots -- Tap

Absorption of water and minerals When the concentration of water is greater outside of the root cells than inside, water moves inside (osmosis)

Xylem Tubes that carry water and minerals from the roots to where photosynthesis will occur Xylem Up!!

Phloem Tubes that carry sugar to areas in the plant where it will be used or stored. Phloem Down!!

Root hairs increase the surface area of the cells.

Functions of Stems 1. Transportation of sugar to where it will be used or stored 2. Transportation of water from the roots to where photosynthesis will take place. 3. Support the plant

Transportation 1. Xylem -- tubes that carry water and minerals from the roots to where photosynthesis will occur 2. Phloem -- tubes that carry sugar to areas in the plant where it will be used or stored.

Types of stems -- Woody Hard, made of dead xylem Annual rings -- the size of the xylem change throughout the year leaving light and dark bands Dark bands -- xylem small and tightly packed; formed during low water (i.e., late summer, fall) Light bands -- xylem large; formed during periods of high moisture (i.e., spring, early summer)

Phloem New Xylem Old Spring Xylem Old Fall Xylem Annual Ring

Functions of Leaves 1. Capture light energy for photosynthesis (Mesophyll) 2. Exchange gases between plants and air (stomata) 3. Control the loss of water 4. Storage of food (used as feed for animals and humans)

The xylem and phloem make up the vascular bundle.

Capturing light for photosynthesis Photosynthesis Water + Carbon dioxide ------> Sugar and Oxygen Palisade layer -- full of cells containing Chloroplasts Chloroplasts -- where light dependent reaction takes place

The Vascular bundle Xylem -- Brings water and minerals to the chloroplast Phloem -- takes sugar and water away from the chloroplast

Exchange of gasses Stomata -- openings on the underside of a leaf Guard cells -- control the opening and closing of the stomata Spongy layer -- spaces where gas can move about

Controlling the loss of water Cuticle -- a waxy layer on the top layer Guard cells and stomata Transpiration

Plant Classification Non Flowering Flowering Ferns Cone-Producers (Conifers) Flowering Monocots Dicots

Monocots Leaves have parallel Veins Fibrous Roots Flower parts in 3’s Seed has one part (cotyledon) Vascular bundles are scattered

Dicots Leaves have branched Veins Tap Roots Flower parts in 4’s & 5’s Seed has two parts (cotyledons) Vascular bundles are in a ring

Plant Reproduction

Asexual Reproduction Reproducing a plant by means other than a seed.

Sexual Reproduction Reproduction that requires the fusion of two gametes. In plants, pollen and an ovule.

Flower Function The primary function of a flower is to produce the seeds needed to continue the species.

Flower Parts

Male Parts of the Flower Stamen which has two parts--filament and anther. Filament: supports the anther. Anther: produces pollen grains. Pollen: Male sexual reproductive cell.

Female Parts of the Flower Pistil: combination of all the female parts. Stigma: receives the pollen grains. Style: supports the stigma. Ovary: surrounds the ovule, later becomes a fruit. Ovule: Female reproductive cell. When the ovule is fertilized with pollen, they produce seed.

Complete and Incomplete Flowers Complete flowers have both male and female parts. Incomplete flowers have either male or female parts but not both.

Other Flower Parts Receptacle: the enlarged part of the flower stalk to which all the floral parts of the flower attach. Sepals: the green leaflike parts of the flower that protect the flower bud. Petals: the colored part of the flower used to attract insects.

Pollination Pollination is the transfer of pollen from an anther to a stigma. Fertilization is when the pollen and ovules come together and develop a seed. Cross Pollination - When one flower fertilized using the pollen from another flower. Self Pollination - When a flower is fertilized with it’s own pollen.

Fruits, nuts and vegetables After fertilization, the ripening seed develops in the pistil. The pistil then enlarges and becomes the fruit. A vegetable is a part of a plant that is grown for its edible parts. A nut is a type of a fruit