6th Grade Science - PowerPoint PPT Presentation

Loading...

PPT – 6th Grade Science PowerPoint presentation | free to view - id: 489cb2-YmMzY



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

6th Grade Science

Description:

6th Grade Science This presentation consists of important information discussed in science class. While students should take advantage of using this resource at home ... – PowerPoint PPT presentation

Number of Views:1796
Avg rating:3.0/5.0
Slides: 66
Provided by: LICE97
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: 6th Grade Science


1
6th Grade Science
  • This presentation consists of important
    information discussed in science class. While
    students should take advantage of using this
    resource at home, it will not be updated
    everyday. Students are expected to use the notes
    taken in class as a primary source of
    information.

2
Genetics
  • Traits- characteristics
  • Heredity- passing of traits from parents to
    offspring
  • Genetics- the scientific study of heredity

3
Gregor Mendel
  • The Father of Genetics
  • Studied pea plants and found that recessive
    traits can be masked by dominant traits, but they
    do not disappear. The recessive traits can be
    carried along in the genes and show up in future
    generations.
  • Dominant-stronger allele (always shows up if
    present)
  • Recessive-weaker allele (masked or hidden by
    dominant allele and only shows up when there is
    no dominant allele present)
  • Homozygous/Purebred- 2 of the same alleles (TT or
    tt)
  • Heterozygous/Hybrid- 2 different alleles (Tt)

4
The Cell
  • The basic unit of life.
  • The human body contains trillions of cells.
  • The cell contains a nucleus.
  • The nucleus contains chromosomes.
  • Chromosomes contain DNA.
  • Genes are segments of DNA that code for specific
    traits.

5
Parts of the Cell
  • Cell Membrane- controls what goes in and out of
    the cell
  • Nucleus- control center
  • Endoplasmic Reticulum- transports material
    throughout the cell
  • Ribosomes- make proteins
  • Golgi Bodies- receive, sort, and send out
    materials to other parts of the cell
  • Lysosomes- break down waste
  • Vacuole- stores food, water, and waste
  • Mitochondria- powerhouse (creates energy for
    the cell)
  • Cytoplasm- gel-like material that contains the
    different organelles.
  • Centrioles- pull apart cells for cell division
  • Chloroplast- uses sunlight to make food for
    plant cells
  • Cell Wall- the rigid wall on the outside of
    plant cells

6
DNAJames Watson and Francis Crick discovered the
double helix structure of DNA
  • Deoxyribonucleic Acid
  • D Deoxyribose Sugar
  • N In the nucleus
  • A Acid
  • Nitrogen Bases (Steps of the Ladder)
  • Adenine-Thymine
  • Cytosine-Guanine
  • Phosphates and Sugars (Sides of the Ladder)
  • Genes- factors that control traits (hair color)
  • Alleles- different forms of genes (brown)

7
Chromosomes
  • Human cells contain 23 pairs of chromosomes, a
    total of 46.
  • Each pair contains one from mom and one from dad.
  • The genes are located on the chromosomes and
    these genes code for specific traits.
  • Stronger Trait-Dominant
  • Weaker Trait-Recessive
  • 2 Dominant TraitsHomozygous Dominant
  • 2 Recessive TraitsHomozygous Recessive
  • 1 Dominant and 1 RecessiveHeterozygous (Dominant
    Trait will show up)
  • Genotype-genetic makeup/allele combination
  • Phenotype-physical appearance/visible trait

8
DNA Replication
  • In order for Mitosis (cell division) to occur,
    each chromatid must make a copy of its DNA so
    that each new cell has the same genetic
    information.
  • Steps
  • DNA double helix unzips
  • Floating Nitrogen Bases in the nucleus match up
    with Nitrogen Bases on the DNA strands.
  • 2 identical DNA molecules are formed, which is 2
    identical sister chromatids, or one chromosome.

9
Cell Division Mitosis
  • Interphase
  • Cell grows to its mature size
  • DNA and cell parts make copies of themselves
  • Cell prepares to divide
  • Mitosis
  • Prophase, Metaphase, Anaphase, Telophase
  • -The nuclear membrane break down
  • -Chromatin condenses to form chromosomes
  • -Chromosomes line up in the center of the cell
  • -Chromatids separate and go to different sides
  • -Two new nuclear membranes form around the
    chromatids as the cell stretches
  • Cytokinesis
  • The cell membrane pinches together in the center
    of the cell and the cell brakes into two
    identical cells.

10
Meiosis
  • Cell division that results in cells with half the
    number of chromosomes (23). These cells are
    important for reproduction, since a new baby will
    need 23 chromosomes from each parent.
  • Chromosome pairs line up in the center of the
    cell and separate to different cells. Those
    cells then go through a second division, much
    like Mitosis, resulting in cells with 23
    chromosomes. The baby will then have 23 pairs of
    chromosomes, or 46 total.
  • A karyotype is a picture of all the chromosomes
    in a cell. It reveals the gender of the baby
    (XXGirl and Xy Boy) and the number of
    chromosomes in the cell.

11
Probability and Punnett Squares
  • Probability- the chances of something happening
  • Punnett Square- a tool/chart used to predict the
    probability of all the possible allele
    combinations that could result from a genetic
    cross.
  • Ex. One parent is homozygous recessive with blue
    eyes and the other is heterozygous with brown
    eyes. What is the probability that the offspring
    would have blue eyes?
  • B b
  • b
  • b
  • There is a 50 chance the offspring will have
    blue eyes since 2/4 boxes show bb.

Bb bb
Bb bb
12
Human Inheritance
  • Phenotype-physical trait (Brown Eyes)
  • Genotype-allele combination (Bb)
  • Codominance-2 alleles are equally dominant (both
    show up) Ex. AB blood type
  • Male (Xy) Female (XX)
  • Sex-Linked Traits-traits whose genes are on the X
    or y chromosome
  • Pedigree-a family tree that traces the presence
    of a traits in past generations
  • Single Genes-trait is controlled by one gene
    (Widows Peak)
  • Many Genes- trait is controlled by more than one
    gene (Height)
  • Multiple Alleles- some genes have more than two
    alleles
  • (Blood Type and Hair Color)

13
Genetic Disorders
Cystic Fibrosis    
14
Sickle Cell Disease    
15
Hemophilia      
16
Down Syndrome    
17
Advances in Genetics
  • Selective Breeding- the process of selecting a
    few organisms with desired traits to serve as
    parents for the next generation.
  • -Inbreeding- crossing two individuals that
    have identical or similar sets of alleles.
  • -Hybridization- breeding two genetically
    different individuals, in order to have the
    offspring receive the best traits from both
    parents.
  • Cloning- making an organism who is identical to
    another.
  • Genetic Engineering- genes from one organism are
    transferred into the DNA of another organism.
  • -gene splicing- DNA molecule is cut open and
    a gene from another organism is spliced into it.
  • Gene Therapy- inserting working copies of a gene
    directly into the cells of a person with a
    genetic disorder.
  • DNA Fingerprinting- fingerprints found at a
    crime scene are used to help identify the person
    responsible for the crime. DNA samples come
    from Blood, Skin, or Hair.
  • -Only identical twins have the same DNA, but
    their fingerprints are different.

18
Tools in Genetics
  • Amniocentisis- a technique by which a small
    amount of fluid that surrounds the baby is
    removed so that the chromosomes can be studied.
    This will then be used for a karyotype.
  • Karyotype- a picture of all of the chromosomes
    in a cell. (Determines if the baby will be a boy
    or girl and if the baby has the right number of
    chromosomes)
  • Punnett Square- a chart that shows all of the
    possible allele combinations that could result
    from a genetic cross and the probability of each
    combination.
  • Pedigree- a chart or family tree that tracks
    which members of a family had or have a
    particular trait.
  • Genetic Counselors- Professionals who use the
    tools above to help couples understand what
    traits can be expected when they have an
    offspring. Ex. genetic disorders

19
Nature of Science
20
The Goal of Science
To understand the world around us
A scientific law (fact) results from a theory
(logical explanation) being tested over and over
by scientists.
The Branches of Science
Life
Earth
Physical
Geology
Chemistry
Biology
21
Problem Solving
Scientific Method a systematic approach to Problem Solving Serendipity a fortunate discovery made by accident
Steps
  • 1. Question Use affect to separate the
    manipulated and responding variables
  • 2. Hypothesis If, then, because
  • 3. Materials Be specific!
  • 4. Procedure Step by step
  • 5. Observations Graphs and Charts
  • Conclusions Answer question/Did you prove your
    hypothesis?

22
Experimental Components
Control Setup setup without the variable
Experimental Setup setup with the variable
Manipulated Variable factor being tested
Responding Variable measurable factor being
affected by the manipulated variable Constants
factors kept the same in both setups Unwanted or
Hidden Variables-variables that we do not plan
for that may affect our results (sometimes
uncontrollable)
Example Question How does the amount of
sunlight affect the lifespan of a plant? Example
Hypothesis If the plant gets more sunlight,
then it will live longer, because sunlight gives
off energy.
23
The Metric System
The standard system of measurement used by
scientists.
Advantages Universal Base 10 Predictable Prefixes Accurate and Precise Units Length-meter Volume-Liter Mass-Gram Temperature-Celsius
Kilo Hecto Deka Meter Deci Centi Milli 1000m 100m 10m 1m .1m .01m .001m Kilo Hecto Deka Meter Deci Centi Milli 1000m 100m 10m 1m .1m .01m .001m
The Metric Family
24
Steps to Converting
  • Underline the unit you know
  • Put your pencil on the unit on the chart
  • Loop from the unit you know to the unit you need
    to know
  • Put your pencil on the decimal point in your
    number
  • Move the decimal point the number of loops and in
    the direction you did on the chart.
  • Remember If the decimal point does not show up,
    it goes to the end of the number!

25
Metric Units
Length Definition The distance from one point to another Standard Unit Meter Tools meter stick, ruler Mass/Weight Definition Mass is the amount of matter in an object and weight is the amount of gravity pulling an object toward earth. Standard Unit Gram Most commonly used Kilogram Tools Triple beam balance, scale Volume Definition The amount of space an object takes up Standard Unit Liter Tools graduated cylinder, beaker, measuring cup, syringe Temperature Definition The measure of hotness or coldness Standard Unit Celsius Tool thermometer
26
Graphing
Temperature Line Graph
Remember
Y
Title X and Y Axis Labels Equal Intervals Key
Temperature (Degrees Celsius)
Time (Minutes)
X
27
Temperaturein Celsius
  • 100 Degrees..Boiling Point
  • 80 DegreesHot Coffee
  • 50 DegreesHot Bath
  • 37 DegreesNormal Body Temperature
  • 21 DegreesRoom Temperature
  • 0 Degrees..Freezing Point
  • -15 Degrees..Snowy Day

28
Floating and Sinking
Volume the amount of space an object takes
up Capacity the maximum amount a space can
hold Weight the amount of gravity pulling on an
object Displacement the space/water pushed
aside when another object takes its
place Buoyancy the upward force keeping an
object afloat Density mass per unit
volume Mass the amount of matter in an object
29
Heat Transfer Heat transfer is The movement of
thermal energy from Warm to cold Conductors allow
heat to transfer through them. Ex.
metal Insulators do not allow heat to transfer
through them. Ex. wool
Types of heat transfer
Conduction Convection
Radiation Direct contact
Indirect contact the sun or
electromagnetic waves
30
Motion, Forces, and Energy
Motion- a change in position where an objects
distance from another object changes. Reference
Point- a place or object used for comparison to
see if an object is in motion. The most common
reference point is the Earth. Force- a push or
pull. Speed- the distance traveled in one unit of
time. Velocity- speed in a given
direction. Momentum-mass x velocity (determines
how difficult it is to stop) Acceleration- the
rate at which velocity changes (speeding up,
slowing down, or changing direction.
31
Friction-the rubbing together of two
objects-causes an object to slow down or stop
Sliding Friction Rolling Friction Fluid Friction
Rubbing hands together, skiing, etc. Bike riding, bowling, etc. Swimming, diving, etc.
32
Forces
  • Force A push or a pull
  • Balanced force equal and opposite (wrestling
    face-off)
  • Unbalanced force unequal and opposite (one
    person wins)

In this case the winner is the gift!
33
Newtons Laws
  • 1 Inertia- An object at rest will stay at
    rest and an object in motion will stay in motion
    unless acted upon by an unbalanced force.
  • 2 Force Mass X Acceleration
  • (the larger the mass, the more force needed to
    make it move faster)
  • 3 Every action has an equal and opposite
    reaction.

34
Simple MachinesMake work easier by multiplying
your effort or changing the direction of your
force.Mechanical Advantage- the number of times
a machine multiplies your effort force (how
helpful the machine is)
  • Inclined Plane
  • Wedge
  • Screw
  • Wheel and Axle
  • Pulley
  • Lever

35

36
Inclined Planea flat, slanted surface
  • Advantage Allows you to use less force over a
    longer distance
  • Example wheelchair ramps

37
WedgeThick at one end and then tapers to a thin
edge at the other end. Two inclined planes back
to back.
  • Examples knife, teeth, ax, zipper
  • Advantages The longer and thinner, the easier
    it is to use.

38
Screwan inclined plane wrapped around a cylinder
  • Examples bolts, faucets, jar lids, light bulb
  • Advantages When the threads are close together,
    it is easier, but takes longer. Effort is
    multiplied over a longer distance.

39
Wheel and Axletwo circular objects that are
fastened together and rotate about a common axis.
The larger object is the wheel and the smaller
object is the axle
  • Examples screwdriver, doorknob, windmill,
    steering wheel
  • Advantages multiplies your force over a longer
    distance

40
Pulleya grooved wheel with a rope wrapped around
it
  • Fixed-attached to a structure
  • Changes the direction of your force
  • Moveable-attached to the object
  • Multiplies your force
  • Pulley System-a combination of a fixed and
    moveable pulley
  • Examples flagpole, blinds

41
Levera rigid bar free to rotate about a fixed
point
  • First Class Lever-fulcrum in between the effort
    and load scissors, seesaw, crowbar
  • Advantage changes direction of force
  • Second Class Lever- load is between the effort
    and fulcrum
  • -Wheelbarrow, door, nutcracker
  • Advantage multiplies effort force
  • Third Class Lever- effort is in between the load
    and the fulcrum
  • -baseball bat, tweezers,
    fishing pole
  • Advantage multiplies effort force

42
Potential and Kinetic Energy
  • Potential energy is stored and ready to use.
  • Kinetic energy is energy in motion.
  • A pendulum stores potential energy before it is
    released and uses kinetic energy as it swings.

43
Pendulum Notes
Pendulum- a weight hanging freely from a fixed
point. Cycle- a system of events that occurs over
and over. System- a related set of objects
working together in one arrangement. Controlled
Experiment- a study designed with a control group
and experimental group, where all factors are
kept constant except one (manipulated
variable). Variable- a factor that changes.

44
Pendulums in our Lives
  • Galileos Influence
  • Grandfather Clock
  • Foucault Pendulum
  • Metronome

45
Galileo
  • Who? A scientist
  • What? He studied pendulums and how they move.
  • When? 1602
  • Where? University of Pisa, Italy
  • Why? These studies lead to further inventions.
  • What did he discover about pendulums?
  • A Pendulum never returns to its release height.
  • All pendulums come to rest.
  • The cycle rate is independent (not dependent
    upon) of the weight or release height.
  • The cycle rate depends on the length of the
    pendulum.
  • Shorter pendulums complete cycles faster

46
Grandfather Clock
  • Who? Christian Huygen
  • What? A clock composed of a pendulum that keeps
    precise time.
  • When? 1656-1657
  • Where? England
  • Why? It revolutionized time-keeping by including
    minutes.
  • Many of these antique clocks have been passed
    down from generation to generation.

47
Foucault Pendulum
Who? JBL Foucault What? An instrument used to
show the rotation of the Earth. When?
1848-1851 Where? Paris, France. Now found in
many areas around the world. Why? It proves that
the Earth rotates. How? A cannon ball attached
to a wire made a circular pattern in the sand,
demonstrating the circular rotation of our planet.
48
Metronome
  • Who? Winkel and Maelzel
  • What? A device that regulates sound for musical
    beats.
  • When? 1814
  • Where? Holland (The Netherlands)
  • Why? Musicians needed a way to keep a regular
    tempo.
  • How? The transfer of momentum allows the weights
    on opposite sides to make the pendulum back and
    forth.

49
Atom- the basic unit of matter
  • 3 particles
  • Protons charge
  • Neutrons no charge
  • Electrons charge
  • If an atom has more protons than electrons, the
    atom is positively charged. If an atom has more
    electrons than protons, the atom is negatively
    charged.

50
Static and Current Electricity
Electricity is a form of energy used around the
world. Static electricity is the build-up of
electrons. (Lightning) Current electricity is the
flowing of electrons. (Wall Outlets)
51
Sources of Electricity
  • Natural
  • Lightning
  • Electric Eels
  • Static
  • Human-Made
  • Batteries
  • Generators
  • Solar Cells
  • Wall Outlets

52
Circuits
  • Circuit- a complete path through which
    electricity can flow.
  • Closed circuits allow electricity to flow.
  • Open circuits do not allow electricity to flow.
  • Conductors-materials with loosely bound electrons
    that allow electricity to flow through them.
    (metals, iron, silver, aluminum)
  • Insulators-materials with tightly bound electrons
    that do not allow electricity to flow through
    them. (wood, plastic, glass)

53
Series and Parallel Circuits
  • Series Circuits
  • One path
  • If one light goes out, all go out
  • Simple
  • The more bulbs, the dimmer they get
  • Parallel Circuits
  • Several paths
  • If one light goes out, others stay lit
  • Complex
  • More bulbs do not affect the brightness, because
    they have their own paths

54
Switches and Short Circuits
  • Switches turn electricity off and on by opening
    or closing a circuit.
  • Short Circuits occur when electricity can bypass
    a component in a circuit.
  • Electricity takes the path of least resistance
  • Short Circuits are dangerous
  • The energy from the battery is drained quickly

55
Resistance
  • The opposition to the flow of electricity
  • The greater the resistance, the dimmer the bulb
  • Percent Error- difference between the code and
    measured value of a resistor divided by the code
    multiplied by 100.
  • Difference/code x 100

56
Electrical Safety
  • Lightning Rods- rods on tall buildings that send
    lightning to a grounding wire.
  • Circuit Breaker- device that shuts off
    electricity when there is too much flowing
    through a circuit.
  • Fuse- a thin metal strip of wire that melts when
    there is too much electricity going through a
    circuit.

57
Voltage
  • The push behind the current in a circuit.
  • Voltage Drop is the voltage used up by a
    component.
  • The sum of the voltage drops in a circuit equals
    the voltage from the source (First Great Truth).
  • The greater the resistance, the more voltage
    needed to push the current through (Second Great
    Truth).

58
Mystery Components
  • Diode-semiconductor that only lets electricity
    flow in one direction (Radio Stations)
  • LED (Light Emitting Diode)- a diode that lights
    up (Game Shows)
  • Capacitor-stores electricity and lets out little
    bursts of light (camera flash)
  • Motor-changes electrical energy(electricity) into
    mechanical(motion) energy (electric fan)

59
Transformation of Energy
  • Motor- changes electrical energy into mechanical
    energy
  • Generator- changes mechanical energy into
    electrical energy
  • Fossil Fuels- change solar energy to heat energy
    to mechanical energy to electrical energy
  • Battery- changes chemical energy to electrical
    energy

60
Fossil Fuels
  • Definition plant or animal remains found in
    rocks underground
  • Examples coal, oil, and natural gas
  • How Drilling removes these fuels from
    underground and they are burned to create steam
    to turn the turbine which then activates the
    generator.
  • Pros-effective, inexpensive
  • Cons-pollution, oil spills, nonrenewable

61
A Few Alternative Energy Sources
  • Hydroelectric Power (Water)
  • Wind Power
  • Solar Power

62
Hydroelectric Power
  • Dams are built to hold back running water. Small
    tunnels let water flow to turn the turbine which
    activates the generator.
  • Pros No Pollution, Once dam is built,
    inexpensive, effective, renewable
  • Cons Building a dam is expensive, floods,
    animals in the water could get stuck in the
    turbine

63
Wind Power
  • Wind turns propellers that act like turbines to
    activate the generator
  • Pros-wind is free, no Pollution
  • Cons-inconsistent, requires a great deal of land
    near coastal areas, land is expensive, birds may
    get caught in propellers, noisy

64
Solar Power
  • Energy from the sun reflects off of mirrors,
    boils water, and the heat can create steam which
    turns the turbine, activating the generator.
  • OR
  • Solar Cells can convert light directly into
    electricity
  • Pros- The sun is free, renewable, and causes no
    pollution
  • Cons-Does not work at night, very expensive to
    build solar panels, needs to be in sunny locations

65
Electromagnets
  • Strong magnets that can be turned on and off.
  • Includes
  • Voltage Source
  • Ferromagnetic Core
  • Solenoid (coil of wire)
  • To increase its strength, increase
  • 1. Voltage from source
  • 2. Nature of Ferromagnetic Material
  • 3. Number of coils on solenoid and make them
    close together
About PowerShow.com