2 Main Types of Plants

 
1) vascular
2) nonvascular




plants that lack tube-like cells and do not have “true” roots, stems, & leaves

2 Main Types of Nonvascular Plants

A small simple nonvascular plant that has both stems and leaves…but NO ROOTS
Mosses are considered nonvascular and are grouped with liverworts because:
a) their vascular (inner) tissue is very simple

b) they both have similar life cycles

Nonvascular Plants: Moss

fine soft stems

leaves are only one or two cells thick

 leaves grow from all sides of the stem
 moss species can be classified by their leaves based on:
 a) Placement of leaves on the stem
 b) Shape of leaves

 Nonvascular Plants: Mosses

 4 uses of  mosses
 1) Food for animals
 EX: worms & snails eat moss
 2) They help hold soil in place to keep it from washing away
 moss that is added to soil to increase the amount of water it holds

 Nonvascular Plants: Mosses

 Moss Life Cycle
 Sexual reproduction-
 form a new organism by the union of 2 reproductive cells
 1) female reproductive cell
 2) male reproductive cell
 Both are located at the tips of the mosses leafy stem
 fertilization
 the joining of the egg and the sperm

  Moss Life Cycle

 sperm and egg of mosses form at the tips of the leafy stems
 sperm of mosses and liverworts must swim to the egg for fertilization
 fertilization
 2) A stalk grows from a fertalized egg
 3) Brown capsule forms at the end of the stalk (stem)
 4) Brown capsule contains spores
 5) Spores are blown away from parent plant…by wind
 6) They land and grow into new leafy plants

 2 Main Types of Nonvascular Plants

 2) liverwort-
 A small simple nonvascular plant that do NOT have roots, stems, or leaves
 H2O and other materials are distributed throughout their bodies by:
 a) osmosis
 b) diffusion

 Nonvascular Plants: liverworts

 General Characteristics facts about liverworts
 1) simplest nonvascular plant
 2) flat body
 3) slippery layer of green cells on the ground
 4) leaves grow in 2-3 flattened rows along the stem

 What two types of nonvascular plants are shown on this rock?

 1) Moss

 2) Liverwort

 Slide Questions Part Two (slides 27-36)

 Directions: Answer the following questions.
 1) List the main types of plants
 2) Define nonvascular.
 3) Define moss and list 3 of the 5 main characteristics of mosses.
 4) Why are mosses considered nonvascular if they appear to have a stem and a leaf?
 5)  List the two ways that moss species are classified.

 Slide Questions Part Two (slides 27-36)

 Directions: Answer the following questions.
 6)  List the 4 uses of moss.
 7) Explain how mosses reproduce.
 8) Define fertilization.
 9) Define liverwort. How so they take in water?
 10) List two of the four characteristics of liverworts.

 Acids & Bases

 By Robert McGee

 Our Goals for today

 To determine the difference between Acids & Bases
 Discuss the importance of studying Acids & Bases
 Perform an experiment dealing with Acids & Bases

 What is the pH scale?

 The pH scale measures how acidic or basic a solution is.

  The pH scale

 The pH scale is the concentration of hydrogen ions in a given substance.

Identifying Acids and Bases

 Acids have a ph from 0-7
 Lower pH value indicates a stronger acid.
 Bases have a pH from 7-14
 Higher pH value indicates a stronger base.

 Definitions of Acids and Bases

 An acid is a substance that breaks into         ions in an aqueous solution.
 A Base (alkaline) is a substance that breaks into           ions in an aqueous solution.
 Note: aqueous solution is any solution where           is the solvent.

 Did we Miss something??

 What happens when the pH of a substance is 7?
 Ans: A pH level of 7 indicates a Neutral Substance i.e: Water!

 Test Your Knowledge

 What is the range of an ACID on the pH scale?
 What is the range of a BASE and what is another name for a BASE?
 Ans: 7-14, Alkaline

 Characteristics Of Acids  

 A sour taste.
 Acids can be characterized by:
 It turns blue litmus paper red
It tastes sour. Try drinking lemon juice (citric acid)

 Characteristics of Bases

 A Base is characterized by:
 A bitter taste. (Milk of Magnesia)
 It feels slippery.  (Soapy Water)
 It turns Red Litmus Blue.

 Why Learn about Acids & Bases?

 What do you think is the pH level of tap water?
 The pH of a swimming pool must be checked periodically. Why?
Is it important for Lakes & Rivers to maintain a certain pH?

Today’s Experiment

Test the pH of Pepsi, tap water, and drain cleaner
GOOD LUCK!!!

SNEAK PREVIE

ANCIENT CIVILIZATIONS

 Ancient Mesopotamia
Ancient Egypt
Ancient India
Ancient China
Ancient Greece
Ancient Rome
 

ANCIENT MESOPOTAMIA

Oldest known civilization
Babylon
Gilgamesh
Hammarabi
Nebuchadnezzar
Ziggurat
Hanging gardens

Models of the Atom a Historical Perspective

 Early Greek Theories

400 B.C. - Democritus thought matter could not be divided indefinitely.
This led to the idea of atoms in a void.
 350 B.C - Aristotle modified an earlier theory that matter was made of four “elements”: earth, fire, water, air.
Aristotle was wrong.  However, his theory persisted for 2000 years.

John Dalton

1800 -Dalton proposed a modern atomic model
    based on experimentation not on pure reason.
All matter is made of atoms.
 Atoms of an element are identical.
Each element has different atoms.
Atoms of different elements combine in constant ratios to form compounds.
Atoms are rearranged in reactions.
His ideas account for the law of conservation of mass (atoms are neither created nor destroyed) and the law of constant composition (elements combine in fixed ratios).

Adding Electrons to the Model

Materials, when rubbed, can develop a charge difference. This electricity is called “cathode rays” when passed through an evacuated tube (demos).
These rays have a small mass and are negative.
Thompson noted that these negative subatomic particles were a fundamental part of all atoms.
Dalton’s “Billiard ball” model (1800-1900)
    Atoms are solid and indivisible.
Thompson “Plum pudding” model (1900)
    Negative electrons in a positive frameworkThe Rutherford model (around 1910)
    Atoms are mostly empty space.
    Negative electrons orbit a positive nucleus

Bohr’s model

 Electrons orbit the nucleus in “shells”
Electrons can be bumped up to a higher shell if hit by an electron or a photon of light.

There are 2 types of spectra: continuous spectra & line spectra. It’s when electrons fall back down that they release a photon.  These jumps down from “shell” to “shell” account for the line spectra seen in gas discharge tubes (through spectroscopes).

Atomic numbers, Mass numbers

There are 3 types of subatomic particles.  We already know about electrons (e–) & protons (p+).  Neutrons (n0) were also shown to exist (1930s).
They have: no charge, a mass similar to protons
Elements are often symbolized with their mass number and atomic number
These values are given on the periodic table.
For now, round the mass # to a whole number.
These numbers tell you a lot about atoms.
      # of protons = # of electrons = atomic number
      # of neutrons = mass number – atomic number

Isotopes and Radioisotopes

Atoms of the same element that have different numbers of neutrons are called isotopes.
Due to isotopes, mass #s are not round #s.
Li (6.9) is made up of both 6Li and 7Li.
Often, at least one isotope is unstable.These types of isotopes are called radioisotopes
Q- Sometimes an isotope is written without its atomic number - e.g. 35S (or S-35).  Why?
Q- Draw B-R diagrams for the two Li isotopes.

 

 

Starlight