Science Grade 8 Lecture Notes Review

Flashcards based on lecture notes about cells, systems, light, optics, fluid dynamics, mechanical systems, and water.

What is Osmosis?

The movement of water in and out of a cell through a semipermeable membrane from a higher concentration to a lower concentration.

What is Diffusion?

Usually gas, but sometimes liquid, moving through a semipermeable membrane from a high concentration to a low concentration without the use of energy.

What does Impermeable mean?

Something that lets nothing through.

What does WAGER stand for in biology?

Waste, Adaptation, Growth, Energy, Reproduction.

What is DNA?

Deoxyribonucleic Acid. It's inside cells, usually in the nucleus, and gives instructions to the cells as to what they're going to grow to.

What are Cells?

The basic unit of life. Every living thing is made up of them.

Name 3 unicellular organisms.

Bacteria, amoebae, and yeast.

What are some types of cells?

White blood cells, fat cells, red blood cells, skin cells, bone cells, muscle cells, nerve cells.

What is Tissue?

A collection of similar cells.

What are Organs?

A collection of tissue that makes up organ systems, and forms a particular function.

Give 2 examples of Structures that accomplish breathing.

Structures such as lungs (in a human) and gills (in a fish).

What are some major organelles in a cell?

Cell membrane, mitochondria, ribosomes, endoplasmic reticulum, lysosomes, nucleus, nucleolus, golgi bodies, cytoplasm, vacuole (& vesicles).

What structures are found specifically in plant cells?

Chloroplast, large vacuole, and cell wall.

What are the parts of a microscope?

Ocular Lens, Body Tube, Revolving Nosepiece, Arm, Objectives/objective lenses, Stage, Stage clips, Coarse Adjustment Knob, Fine Adjustment Knob, Diaphragm, Light source, Base.

List the organs in order within the digestive system.

Mouth, Esophagus, Stomach, Small intestine, Large intestine, Rectum, Anus

What are the accessory organs of the digestive system?

Liver, Pancreas, Gallbladder

What is the function of the liver in digestion?

Secretes bile to digest fat in small intestine.

What is the function of the gallbladder in digestion?

Stores, and then releases bile that is stored in liver.

What is the function of the pancreas in digestion?

Secretes digestive enzymes into small intestine to aid digestion; Regulates the absorption and production of energy.

What is the main function of the circulatory system?

Delivers oxygen and nutrients to cells and takes away waste.

Describe the flow of blood through the heart.

Superior and inferior vena cavas, right atrium, right ventricle, pulmonary artery, lungs, pulmonary vein, left atrium, left ventricle, aorta.

What are the major types of blood vessels?

Arteries, veins, and capillaries.

What are the components of blood?

Plasma, red blood cells, white blood cells, and platelets.

Name 3 diseases or malfunctions of the circulatory system.

Heart attack, high blood pressure, and arrhythmia

Name 2 technologies used to treat circulatory system problems.

Pacemaker and electrocardiogram.

What are the main functions of the respiratory system?

Inhales oxygen, passes oxygen through/into body, gets carbon dioxide out of the body, exhales carbon dioxide.

What are the parts of the respiratory system?

Trachea, lungs, diaphragm, bronchi, bronchioles, and alveoli.

Name two common respiratory diseases.

Asthma and bronchitis.

What are the components of the excretory system?

Kidneys, ureter, bladder, urethra.

What are the functions of the excretory system?

Balances body fluids, hormones, and nutrients; detects and filters waste in the body; expels waste from the body as urine.

Name 2 diseases/malfunctions of the excretory system.

Kidney stones and renal cell cancer.

Name 2 technologies used to treat excretory system problems.

Kidney transplants and hemodialysis machines.

What are the functions of the nervous system?

Senses internal and external changes and is the control center that makes everything run smoothly.

What are the two main parts of the nervous system?

Brain and spinal cord.

What are the parts of a neuron?

Cell body, dendrites, myelin sheath, axon terminal, axon, nucleus.

What are the parts of the brain?

Parietal lobe, frontal lobe, occipital lobe, temporal lobes, brainstem, hypothalamus, hippocampus, cerebellum, cerebrum.

What are three types of shadows?

Umbra, penumbra, and antumbra.

What are the parts of a wave?

Crest, trough, wavelength, rest, amplitude, frequency.

Who won a Nobel Prize for explaining the photoelectric effect?

Einstein for explaining the photoelectric effect.

What are three types of mirrors?

Concave, convex, and plane mirrors.

What is the line that comes out of the medium after refraction?

Emergent ray.

What is the difference between how concave and convex lenses refract light?

Concave converges, convex diverges.

What are the sources of light?

Fusion, incandescent, fluorescent, phosphorescent, chemiluminescent, and bioluminescent.

What are the parts of an eye?

Ciliary Muscles, Cornea, Pupil, Aqueous Humor, Iris, Lens, Vitreous Humor, Sclera, Tapetum, Optic Nerve, Blind Spot, Retina.

In a healthy eye, where is the focal point of the lens?

The focal point of the lens in your eye is at your retina.

What are two common vision problems related to focal point placement?

Hyperopia (farsightedness) and myopia (nearsightedness).

What are the types of telescopes

Binoculars, refracting telescopes, reflecting telescopes, Cassegrain telescopes, Space (Webb) telescopes

List the electromagnetic spectrum from weakest to strongest.

Radio waves, Microwaves, Infrared, Colors, Ultraviolet, X-Rays, Gamma Rays.

What picture does rods detect at low layer of light?

Black and white/darkness and brightness.

What are the states of matter?

Liquid, gas, and solid.

What are five ways the particle model behaves?

They are always moving, they never touch, all particles in a pure substance are the same, everything is made up of tiny particles (atoms), particles are attracted to each other.

Formula for calculating density

Density = Mass/Volume

What is Viscosity?

A fluid’s ability to flow.

How does temperature affect the viscosity of liquids and gases?

Liquid decreases, gas increases.

What are two methods for measuring viscosity?

Ramp method and falling sphere viscometer method.

What is a solute?

Substance dissolving, usually solid.

What is a solvent?

What the substance is being dissolved in.

A solution

Solute has already been dissolved in solvent, and is a homogeneous mixture.

What are the types of saturation?

Unsaturated, saturated, supersaturated.

What are the conditions where you can change the rate of dissolving?

Agitation, particle size, temperature, and pressure.

What does WHMIS stand for?

Workplace Hazardous Materials Information System

What does SDS stand for?

Safety data sheets

What information can be found on a SDS?

Technical information on the substance, a list of hazardous ingredients, chemical hazardous data, control measures, personal protective equipment that should be used, instructions in preventing accidents with using the chemical, handling, storage, and disposal procedures, and emergency procedures in case of accident.

What are common WHMIS symbols?

Flammable, oxidizing, poisonous, health hazard, compressed gas, corrosive, environment, biohazardous.

What are the types of pure substances?

Elements and compounds.

What are two types of mixtures?

Homogenous and heterogenous.

Why are gases compressible?

Gas particles have a lot of space between them so they come closer under pressure.

Why are liquids incompressible?

Liquid particles have no space between them

What is Pascal's law?

Any pressure on a trapped fluid is transmitted equally through the fluid in all directions.

What are 2 different kinds of systems associated with pressure laws?

Hydraulics and pneumatics

What is the formula for calculating pressure?

Pressure = Force/Area

What are the 6 simple machines?

Lever, inclined plane, wedge, screw, pulley, and wheel and axle.

What are the three classes of levers?

Class 1, Class 2, and Class 3.

What is a lever?

It’s a bar that is free to rotate around a fixed point (fulcrum).

What is an inclined plane?

A ramp that reduces the force needed to move something, but it increases the distance you need to move it.

What is a screw?

A screw is technically an inclined plane or a thread wrapped around a cylinder, usually coming to a sharp point at one end.

What is an example of a different pulley?

Single fixed pulley, single movable pulley, compound pulley, and block and tackle.

What is the general formula for mechanical advantage(MA)?

MA = Output Force/Input Force

What is the formula for MA of gears?

MA = # of Driven Teeth/# of Driver Teeth

What is the formula for speed ratio?

Speed Ratio = # of Driver Teeth/# of Driven Teeth

How is Work measured?

force x distance

How do you measure efficiency?

Output/Input x 100 but with work (joules)

What creates are U-shaped valley?

Glaciers grind down the rock on both the side and bottom of the area where they are traveling. The result is a large wide U-shaped valley.

How is a glacial kettle formed?

Block of ice is dropped off by a glacier, ice block becomes surrounded by sediment, ice block melts.

What is an example of a Delta?

Located at the mouth of a river and rivers leave sediment here.

How does water erosion happen?

When river builds speed on the outside and erodes the land

What are the stages of the hydrologic cycle?

Evaporation, Condensation, Precipitation, Transpiration.

What is Ocean Acidification?

When CO2 dissolves into the ocean, lowering ph level (making it more acidic)

What is Bottom trawling?

Dragging a net the size of multiple football fields across the bottom of the floor

What is Bycatch?

Unwanted animals sent back to the ocean dead (95% of bottom trawling is bycatch)

What tracks the movement of water through oceans, land, and atmosphere?

gravity Recovery and Climate Experiment (GRACE)

What happens when water is depleted?

When we drain aquifers too much, the water goes lower down in the ground

Give examples of what pushes to collapse the fish stocks

Overfishing, Bottom trawling

What is fish that is keystone species in its environment?

Salmon

How is it dangerous without oxygen in ocean environment

Without oxygen, fish and sea life can’t survive. Algae bloom doesn’t let oxygen in, creating a dead zone

What are Bioindicator?

An animal that indicates changes in an environment since they’re very sensitive

What are different types of dam?

Check Dams: control erosion/flooding; Diversion Dams: divert river water to irrigate crops; Flood Control Dams: earth dams; Hydroelectric Dams: electricity making ones

What does filtration does Lifestraw do?

Doesn’t work for saltwater or chemical contamination, has series of filters, has beads so tightly packed it doesn’t let dirt or bacteria through, and has activated carbon that kills any living creature

What water environments Does Distillation/Desalination purify?

Works for everything, saltwater is evaporated, water goes through a tube, cools back into clean water