SCIENCE 7 FINAL REVIEW

2015

Atoms

The smallest piece of an element that still is that element. Example: the smallest piece of gold that still is gold.

Made of protons, neutrons and electrons. The Atomic Number=Protons=Electrons The Atomic Mass-Protons=Neutrons

Element

A substance that can not be broken down into any other substances by physical or chemical means.

They are one type of pure substance made of many of the exact same atoms.

Ex. Gold, Oxygen, Sodium etc.

Compound

A substance made of two or more elements chemically combined.

Ex. Water: H2O Sugar: C6H12O6 etc. Think of compounds as a big bucket of

water or a bag of sugar.

Molecule

The smallest part of a compound consisting of 2 or more atoms chemically bonded together.

Think of teeny tiny things made of atoms. Ex. One molecule of H2O . This would be

very small because it’s only two atoms of Hydrogen and one atom of oxygen. TOO small to quench your thirst! Hahaha!

Phases of Matter

Solid: Atoms and/or molecules of a material tightly packed together. Low energy. Ex. An iron bar

Liquid: Atoms and/or molecules more loosely packed together so they can move around a little. Medium energy. Ex: Hot melted iron, mercury etc.

Gas: Atoms and/or molecules very far apart so they can move freely about. High energy. Ex: Oxygen, Carbon Dioxide etc.

Physical and Chemical Change

Physical Change: A change in the size, shape or state of a substance. The substance is the same before and after the change.

Ex. Cut silver in half or melt it. It’s still silver!

Chemical Change: When a substance is changed into a new substance or substances.

Ex: burning wood changes into ash (carbon) carbon dioxide(CO2,) carbon monoxide (CO) and H2O vapor. This cannot be reversed! All chemical reactions fall into this category!

Metric Length Measurement

How long is the nail and pencil? Answers: 5.5 cm (nail), 9.9 cm (pencil)

Graphing

Example:

Temperatures In NY CityDay Temperature

1 43° F2 53° F3 50° F4 57° F5 59° F6 67° F

Putting Data on Graph

X Axis for Graph

The X axis is always the independent variable meaning that it will control the Y axis variable.

Time (day, in this case) will control the Y axis (temperature, in this case.)

In other words, the day controls the temperature! Temperature does not control the day.

The Y Axis

The Y axis is always controlled by the X axis.

Example: Which would be the X variable and Y variable in this case: Plant Growth and Fertilizer use?

Fertilizer use: X axis, because it controls the plant growth.

Plant Growth is the Y axis. It’s controlled by fertilizer use.

Volume Measurement

For rectangular solids: Length times width times height. Ex. 2cm x 2cm x 3cm=12cm3

For irregular shaped objects: The water displacement method. The units are milliliters in diagram.

Cells

Animal Cell

Cells

Plant Cells

Major Points About Cells

You will need to remember how plant cells differ from animal cells.

Plant cells have: a cell wall for shape and support. Plants

don’t have bones! Chloroplasts; to make food (simple sugar)

from sunlight. Animals eat food which is broken down into simpler substances!

Both Plants and Animal Cells

Have nuclei: The cell control center. (Brain)

Have mitochondria: to turn food into energy.

Have cell membranes to control what enters and leaves the cell.

Each organelle has a function which is to perform a task to either keep the cell alive or give it the ability to reproduce. (Asexually by cell division.)

Respiration and Photosynthesis

Photosynthesis: The process by which plants use the sun’s energy to produce a simple sugar used as food and waste products like O2.

6CO2 + 6 H2O + energy->C6H12O6 + 6O2

Respiration: When a cell brings oxygen into it’s mitochondria to add to food molecules to produce energy and waste products like CO2 and H2O

C6H12O6 + 6O2 -> 6CO2 + 6 H2O + energy Plants use respiration too after they make their

food. What O2 they don’t use is given off to the environment for animals to use!

Metabolism

The chemical processes occurring within a living cell or organism that are necessary for the maintenance of life. In metabolism some substances are broken down to yield energy for vital processes while other substances, necessary for life, are made.

Classification of Living Things

Kingdom The most general Phylum Class Order Family Genus Species The most Specific

Classification of Living Things

Kingdoms: The most general category of living

things. Animal Kingdom: Multicellular . They grow

and develop although some undergo a process of metamorphosis later on in their life. Most animals can move spontaneously and independently. All animals must ingest other organisms or their products for food. Examples: Insects, fish, birds, humans and crustaceans etc.

By the way…

Metamorphosis is: The physical change in an organism from

one type to another that is part of their life cycle.

Example: A caterpillar changing into a butterfly.

Plant Kingdom

Plants are multicellular organisms that sexually reproduce and are capable of using photosynthesis to make their own food from sunlight.

Fungi Kingdom

Single celled or multicellular organisms. Reproduce asexually using spores. They are decomposers which means they digest things outside of their bodies. Examples: some yeasts, molds and mushrooms.

Monera Kingdom

Single celled organisms that lack a nucleus.

Recently broken into two groups: Archaebacteria-have a cell wall Eubacteria-true bacteria, no cell wall. Examples: All bacteria

Protist Kingdom

Mostly Unicellular Have a nucleus Example: Amoeba

Asexual Reproduction

Reproduction by which offspring arise from a single parent, and inherit the genes of that parent only.

Examples: budding (an offspring grows off of the parent.) Fission (The parent splits creating two new individuals.) Spores (Offspring grow from spores released by the parent.)

Sexual Reproduction

a process that creates a new organism by combining the genetic material of two organisms, male and female.

Most plants and animals use this method Plants: Pollen and egg Animals: Sperm and egg

Cell Division: Mitosis

Mitosis is the process by which a cell separates the chromosomes in its cell nucleus into two identical sets, in two separate nuclei.

The “daughter” cells will have the same number of chromosomes as the parent cell

This is how organisms grow in size!

Chromosomes

Bundles of genes. Contain the genetic information of an

individual. Humans have 46 in each nucleus.

Genes

A gene is a distinct portion of a cell’s DNA.

Genes are coded instructions for making everything the body needs, especially proteins. Human beings have about 25,000 genes.

DNA

A nucleic acid that carries the genetic information in the cell and is capable of self-replication .

Portions of DNA are genes.

Cell Division: Meiosis

a special type of cell division necessary for sexual reproduction.

The cells produced by meiosis are sex cells (sperm or eggs) and have half the amount of genetic information from the parent. When they combine they share half the info from the male parent and half the info from the female parent.

Mitosis and Punnett Squares

During sexual reproduction, half the genetic info for the male combines with half from the female.

Genes from a male are made of two alleles which can combine with the two alleles from a female. What the offspring inherits can be predicted using a Punnett Square.

Punnett Squares

When a hybrid green pea plant sexually reproduces with another hybrid green pea plant. The offspring have a 25% chance of being a purebred green pea plant (GG), 50% chance of being a hybrid green pea plant (Gg) and 25% chance of being a yellow pea plant (gg).

See next slide.

Punnett Square

Dominant AlleleDominant allele

Recessive Allele

GG-purebred greenGg-hybrid greengg-purebred yellow

75% Green25% yellow

Dominant Vs. Recessive Alleles

Dominant alleles always overpower recessive alleles. That means that particular trait will show up in an organism.

Purebred Vs. Hybrid

Purebreds (homozygous)have the same allele for a gene: Example: GG or gg. One would be GG, it’s green, gg is yellow.

Hybrids (heterozygous) have two different alleles for a gene. Example: Gg. Since G (green) is dominant, if it’s in the gene, it will be green.

Phenotype Vs. Genotype

Phenotype is what an organism looks like. Example: the pea is green

Genotype are the genes the organism has.

Example: the pea has a GG gene.

Extinction

When a species of organism no longer exists on the planet.

Causes: Over hunting/usage by humans, natural events, being unable to survive due to loss of living space (habitat) or predation by other living organisms etc.

Unicellular and Multicellular

Unicellular means: Made of one cell. Multicellular means: Made of more than on cell.

Order of Complexity for Living Things

Cells, tissues, organs and organ systems. Cells the basic unit of structure and function

in living things. Tissue: The same type of cell working

together. Example: Muscle tissue. Organ: A group of tissues that perform a

specific function. Example: Muscle tissue making up the heart.

Organ System: A group of organs working together. Example: The heart, veins, arteries and capillaries w/blood serving the body.

Organ Systems

All organ systems work together. Examples of organ systems that work

together: The nervous system, excretory, circulatory, respiratory, digestive and endocrine systems.

Circulatory System

Heart, blood, veins (Away,) arteries (toward) and capillaries (in between.)

Brings needed materials to cells, like oxygen and food for respiration. Removes wastes from cells like carbon dioxide and water.

Helps to repair cuts by clotting at wound site.

Blood Types

Type A: Will clump with anti-A serum Type B: Will clump with anti-B serum Type AB: Will clump with both anti A and

B Type O: Will not clump with either.

Universal Donor!

Oxygen Poor Side

Oxygen Rich Side

Respiratory System

Includes the trachea, bronchi and lungs. Allows for gas exchange between lungs

and blood. Oxygen goes to blood, carbon dioxide and water vapor leave blood.

The Respiratory System

Alveoli are at the ends of the bronchioles where gas exchange occurs. Not seen in diagram.

Excretory System

Organs: Kidneys, nephrons, ureters, urinary bladder and urethra.

Function: To remove wastes like urea from the blood stream.

The liquid Excretory System

Digestive System

Includes esophagus, stomach, small intestine, large intestine, rectum and anus.

Allows for the breakdown of food into simpler substances, absorption of water and the elimination of solid indigestible substances.

The Digestive System

Nervous System

Includes Brain, spinal chord and nerves. It is the control system of the body. Allows the body to think and respond to

stimuli. Stimuli are things that the body senses.

Example: You touch something hot (stimulus) and your body responds (takes hand away.) Includes how you react to what you see, hear, smell, touch and taste. (Your senses.)

What Brain Parts Control

Cerebellum: coordinates the use of muscles and maintains balance.

Cerebrum: Interprets information from the senses and is the memory/learning/ judgment area of the brain.

Brain Stem: Controls breathing, heart rate and other involuntary actions.

Endocrine System

Includes the glands that produce hormones to instruct your body.

Examples: Thyroid Gland, Testes and Ovaries. Thyroid: controls how quickly the body uses energy,

makes proteins, and controls how sensitive the body is to other hormones.

Testes: Secretes testosterone which helps the body grow hair, lots of facial hair. Testosterone also helps create/grow the male reproductive system and more.

Ovaries: Produce estrogen which tells the female body when it’s time to start the menstrual cycle and more.

The Skeletal System

Shape and Support Protects organs Helps us move Produces blood cells Has joints

Know your bones!

JOINT TYPES

Hinge Pivot Ball & Socket

Immovable Gliding

Ligaments Vs. Tendons

Tendons hold muscle to bone

Ligaments hold bone to bone.