Download Chapter 12: Plants (pgs. 291-302) Heather Mims Classification and

Chapter 12: Plants
(pgs. 291-302)
Heather Mims
Classification and Composition of Living Things
 Classification of Living Things
o Kingdoms are subdivided into phyla/ divisions groups
o Phyla are subdivided into classes  orders  families  genera  species 
varieties/ hybrids
o The “neither plant nor animal” group is divided into several Kingdoms

Protista

Monera

Fungi
o The plant kingdom called Plantae/Metaphytae kingdom contains more than
265,000 species
 When classifying organisms, scientist give each phylum and its subgroups scientific
names that are Latin or have been Latinized
o Latin is a universal and unchanging language
o scientific naming makes the classification of organisms definite so there can be no
duplication
o scientific name of an organism is actually formed from two categories: the genus
and species
Composition and life Processes of Organisms
 All organisms have life cycles
 The basic unit of structure and function for all organisms is the cell. This is also the cell
theory.
o all organisms are composed of one or more cells
o the cells is the basic unit of organization of organisms
o all cells come from preexisting cells
 Depending on their internal organization, cells are of two types – prokaryotic and
eukaryotic.
o prokaryote: an organism with a cell that lacks internal structures and is
surrounded by membranes; single-celled organisms.
o eukaryote: organism that has cells containing internal membrane-bound
structures, called organells. The largest organell is a membrane-bound nucleus
that contains the cell’s DNA and manages the cell’s functions.
 All cells have an external boundary, called the plasma (cell) membrane, that separates the
cell from its external environment.
o controls what enters and exits the cell
o food and oxygen needed enter through this membrane
o carbon dioxide and waste materials exit through this membrane
 Some cells have an outer rigged covering called a cell wall.
 Activities of eukaryote cell are controlled by the nucleus.
o nucleus is held together and surrounded by a nuclear membrane
o nucleus contains the cell’s genetic material, called DNA
 Fluid part of the cell, outside the nucleus but inside the cell membrane, is called
cytoplasm.
o Cytoplasm contains organelles, endoplasmic reticulum, ribosomes, vacuoles, and
mitochondria (which play an important part in cellular respiration such as
generating energy from the breakdown of food, and chloroplasts).
 Not all cells are alike.
 A group of specialized cells working together to perform a specific function is called a
tissue.
 Two or more tissues working together for a common function make up an organ.
o examples of human organs: skin, heart, brain
o examples of plant organs: root, stem, leaf
 A group of organs working together make up an organ system
o organ systems work together to maintain life and health
o example of human organ system: digestive system
o example of plant organ system: flower
 Cells exhibit the characteristic activities of life, called the life processes.
o life processes specific to plants: photosynthesis, transpiration, cellular respiration,
digestion, circulation, assimilation, growth, excretion, reproduction, and tropisms
o disease can cause a breakdown in one or more of the life processes
 Cellular respiration is the breakdown of molecules of food to release energy used for
building new cells
 Digestion is the mechanical and biochemical breakdown of food into molecules small
enough for the body to absorb.
 Excretion is the process of eliminating waste at the cellular level.
 Motion is the process of movement, either from one place to another or within a
stationary location.
o examples of movement from one place to another: walking, swimming, birds
flying
o examples of movement within a stationary location: leaves of plants moving with
the wind, or in respect to the Sun’s location
o the response of a plant to stimulants such as heat, water, gravity, or light is called
tropism
o the response an organism has to light specifically is called phototropism
o the response an organism has to gravity specifically is called geotropism
o the response an organism has to water specifically is called hydrotropism
o the response an organism has to touch specifically is called thigmatropism
o the response an organism has to heat specifically is called thermostropism
o the response an organism has to chemicals specifically is called chemotropism
 Reproduction is the process of creating new individuals from existing ones.
o at the cellular level: cell division
o simple cell division is a method of asexual reproduction
o cells experience a cycle of growth and division called the cell cycle
 The cell cycle consists of two phases/steps
o interphase: growth period
o mitosis: cell division into two daughter cells
 Mitosis involves four phases:
o prophase: visible beginning and longest lasting period; chromatids are formed
o metaphase: characterized by the alignment of the chromosomes in the center of
the cell
o anaphase: characterized by the separation of sister chromatids toward opposite
poles of the cell
o telophase: final phase; characterized by the formation of nuclear membranes
around the two new daughter nuclei
 Sexual reproduction involves the union of two cells to create a new individual
o important to sexual reproduction is a unique process of nuclear division called
meiosis
o through meiosis, sex cells (gametes – egg and sperm cells) are produced
o meiosis consists of two separate division, meiosis I and meiosis II
o when gametes unite a process called fertilization begins
o the union creates a zygote
 Mitotic cell division is the process when multicellular organisms increase their number of
cells for growth, healing, and maintenance.
o is also the asexual method used to produce new organisms, such as in budding,
which occurs in plants and some animals
The Plant Kingdom
 The Plant Kingdom, scientifically called Plantae Kingdom or Metaphytae Kingdom, is
divided into as many as 10 divisions or phyla:
o Bryophytes; mosses and liverworts
o Psilophyta; whisk ferns
o Lycophyta; club mosses
o Sphenophyta; horsetails
o Pterophyta; ferns
o Cycadophyta; cydads
o Cnetophyta; highly specialized trees, shrubs and climbing vines
o Ginkgophyta; only one living species Ginkogobiloba
o Coniferophyta; conifers
o Anthophyta; flowering plants
 Members of the plant kingdom have chlorophyll and manufacture their own food by
photosynthesis; they are autotrophic
 Can be divided into two broad groups: bryophytes, or plants that have no vascular tissue
and tracheophyts, or plants that do have vascular tissue.
The Bryophytes
 Bryophytes reproduce both sexually and asexually
o examples are mosses
o moss plants have cells that are capable of retaining large amounts of water
 Bryophytes are small, but found all over the world, always on land, and in areas where it
is damp with fresh water
 Liverworts are flat, with broader “leaves”
o commonly found on the soil of moist and seldom used pathways
 The term moss is frequently used incorrectly for plants that have no affiliation with a true
bryophyte.
o for example “Spanish moss” is not actually a moss but a member of the
tracheophyte family
 Bryophytes play an important role in soil formation.
o they can grow in areas that have very little soil or minerals and where more
complex plants cannot be established
o first organisms to inhabit devastated area
o along with other simple plants help to make and bind the soil so that larger and
more complex plants can establish themselves and continue the process of
rebuilding
The Tracheophytes
 Plants that contain vascular tissue in their roots, stems, and leaves.
 Vascular tissue is used to transport materials through the organism.
 Usually have chlorophyll and are green in color.
 Divided into those that have seeds and those who don’t
o ferns, horsetails, and club mosses have roots, stems, and leaves but no flowers,
fruits or seeds
 Seed plants, which produce flowers, fruits, and seeds, include all trees, shrubs, crop
plants and vegetables, garden and wild flowers, and grasses.
o seed plants grow in soil and in fresh water
o smallest seed plants are the duckweeds, which grow floating on the water in
ponds and slow moving streams
o largest are the giant sequoias and redwoods of California
 Angiosperms have seed coverings.
o produce flowers that turn into fruits with seeds
o examples: garden and wild flowers, plants that produce crops and vegetables,
grasses, cereal grains, trees and shrubs that lose their leaves in autumn.
 Gymnosperms, meaning “naked seed,” are those without seed coverings.
o also called conifers because they produce woody cones
o leaves are in the form of either needles or flat scales
o examples: pine, spruce, fir, cedar, bald cypress, redwood, hemlock, yew, and
larch trees
Ferns, Horsetails, and Club Mosses
 Vascular plants without seeds.
 Sizes range from small mosses to large trees.
 They have true roots, stems, and leaves, but they do not produce flowers, fruits, or seeds.
 Mostly land plants that grow best in cool, damp, shaded places where the soil is rich in
humus.
 All have chlorophyll, are green in color, and are autotrophic.
Ferns
 Numerous millions of years ago; formed large forest in the wet marshy land
o giant ferns grew as large as trees
o ferns are much smaller in temperate zones
 Stems of ferns are underground, growing horizontally just under the surface; these stems
are called rhizomes.
 In most ferns the only part of the plant that appears above the ground are the leaves, or
fronds
 They go through a reproductive cycle, having both a spore stage and a sexual stage
 They can also reproduce asexually
Horsetails and Club Mosses
 Similar to ferns, especially in how they reproduce, however most of them are now extinct
and their remains are seen as leaf and stem fossil imprints
 They have horizontal stems and upright branches grow from these stems.
o some of their upright branches have bushy side branches
o other upright branches produce spores in cones that develop at their tips
 Club mosses are small, low-growing evergreen plants
o grow best in damp places, on the ground in temperate climates and on tree trunks
in tropical climates
o upright branches look like the leaves of fir and spruce trees
o produce spore in cones that grow at the tip of their branches
o some can be found being used in making Christmas decorations and other
ornamental arrangements
Roots
 Roots are the part of plants that anchor them by growing downward and outward in the
ground
o when the seed begins to grow the first root to appear is called the primary root; it
grows rapidly, pushing its way through the soil; examples are carrots and radishes
o secondary roots branch out from the primary root until a root system is formed
 There are two main kinds of root systems: taproot system and diffuse root system
o taproot system: primary root grows until it is the largest root and smaller
secondary roots grow from it
o diffuse root system: primary root only lives a short time and the secondary roots
continue to grow as a cluster at the base of the stem; the cluster becomes what is
sometimes called a fibrous root system; examples: corn, grass
 Roots of some plants can grow from the stems/ leaves of plants and are called
adventurous roots
o examples: tomato, cucumber, potato, and squash plants
o some plants send out roots from their stems just above the ground, these are called
prop/ brace roots (they help to hold up the plant); example: corn
o climbing plants such as English ivy, poison ivy, and tropical orchids, send out
roots from their stems; these are called aerial roots; they grow above the ground,
clinging to a wall or tree, and hold the stem firmly in place
 The tip of the root is the root cap. This protects the delicate end of the root and contains
most of the cells that by their rapid mitotic cell division add length and width to the root.
 Root hairs are tiny, nearly microscopic, and found a short distance behind the tip of the
root.
o they aid in anchoring the plant and play a major role in absorbing water and
dissolved minerals from the soil
o as the root grows, new root hairs form near the tip and the older ones die and
wither from abrasion
 The length of a root varies depending on the species of the plant and conditions of the
environment.
 Roots do not necessarily grow down.
o it’s true that roots tend to grow toward gravity, but their main direction is toward
water; it does this because of biochemical reactions taking place inside the root
cells
 Roots have several important functions for the plat system.
o help anchor the plant
o root hairs give off acid that help dissolve minerals in soil
o absorb water and minerals which are then sent through the stems and leaves
 Humans have many uses for roots.
o food; examples: carrot, turnip, parsnip, radish, beet, sweet potato
o seasonings; examples: horseradish
o source of medicine; examples: sassafras, ginger, yew, Ginkgo, licorice, and
mandrake
o making candy; examples: licorice and ginger
o making dyes; examples: madder and yellowwood trees
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Chapter 12 Summary
(pgs. 304-318)
Kara Chisum
Stems
Definitons and Kinds of Stems
Herbacceous, woody, aerial, shortened, creeping, climbing, erect, underground,
rhizomes, tubers, bulb, corm
Structure and Growth
Occurs at the tip
Bark, phloem tissue, sapwood, hardwood, pith, cambium, annual ring
Function
Supports leaves and flowers
Transfer of nutrients
Human Uses
Food, rubber, linen, medicines, ropes, dyes, turpentine, and heating
Leaves
Structure
Blade, petiole, leaf veins
Patterns: Palmate, pinnate, parallel
Simple leaf or Compound leaf
Functions
Makes chlorophyll
Attracts light and carbon dioxide
Change Color
Stop making chlorophyll in fall and winter
Human Uses
Food, tea, spice, flavoring, medicines
Flowers
Definition and Structure
Receptacle, sepals, calyx, petals, corolla, nectar, accessory parts, essential parts,
stamens, filament, male gametes, pistil, stigma, style, ovary, ovules, seeds
Pollination and Fertilization
Pollination, self-pollination, cross pollination, ficial pollination, selective breeding, pollen
tube, fertilization, fruit
Human Uses
Decoration, food, dyes, perfume, seasoning, spice, oils, medicine
Fruits and Seeds
Definition and Function of Fruit
Pome, drupe, berry, multiple fruit, dehiscent fruits, indehiscent fruits
Definition and Function of Seeds
Embryo, seed coat, cotyledon, germinating, seedling
Human Uses of Seeds
Food, oil, cloth, soap, candles, butter substitutes, paint, varnish
Fruits Without Seeds
Caring for Earth’s Plants
Understanding the Conditions Necessary for Plant Growth
Tropics, Antarctic, temperate climate, warm desert
Preserving Earth’s Precious forests and Wildflowers
Learning Activities
Stem Growth Occurs at the Tip, Not at the Bottom
Function of a Leaf and its Stomata
Leaves, Chlorphyll, and Photosynthesis
Flowers and Pollen
Exploring Developing Ovaries
Exploratory Activities for Plants
Exploring a bryophyte
Exploring Leaves by classifying them and by making leaf collections and leaf prints