MCA Science Review

Genetics

Genetics

the study of how traits are passed on

Heredity

the passing on of traits from parent to offspring (child)

Chromosomes

fine, threadlike structures made of DNA, found in the nucleus, you have 46 in every cell

DNA

contain your genes, the "instructions" for your body, made up of 4 bases (A, G, C, and T)

Gene

a unit of heredity that has a specific location on your DNA/chromosomes and codes for a particular trait

Traits

characteristics of living things (examples: eye color, height, nose shape)

Genotype

genetic code used for each trait; represented as letters

Phenotype

the trait that can be seen; physical appearance

Dominant

traits that present (show) themselves; (uppercase letters)

Recessive

traits that "hide"; will only show themselves if there are two of these genes; (lowercase letters)

Heterozygous

two different versions of a gene (two different sized letters)

Homozygous

two identical versions of a gene (two letters of the same size)

Allele

Different versions of a trait or gene

Ecology

study of relationships of living and non-living things

Environment

our surroundings

Ecologist

a person who studies ecology

Ecosystem

an area where the living and non-living things interact and affect each other

Biome

a large geographic area with a certain climate which determines the plants and animals there (i.e. grassland, desert, rainforest, deciduous forest)

Habitat

the area where a plant or animal lives or grows naturally

Abiotic factor

non-living things

Biotic factor

living things

Community

a group of populations that interact

Population

a group of one kind of organism

Population Density

the number of organisms in a given space

Limiting Factors

something that prevents a population from reaching its biotic potential

Biotic Potential

the maximum population that could be produced under the best possible conditions/resources

Carrying Capacity

the maximum population that could be produced using the resources that are available (not necessarily the best though)

Symbiosis

living together

Mutualism

both organisms benefit from the relationship

Commensalism

one organism benefits and the other has no effect from the relationship

Parasitism

one organism benefits and the other is harmed from the relationship

Parasite

an organism that lives in or on another organism and harms or kills it

Host

the organism that is harmed or killed due to a parasite living on or in it

Biodiversity

the variety of living things in an area

Food Chain

shows what eats what; shows the energy flow

Predator

an organism that hunts an eats another

Prey

an organism that is hunted and eaten

Food Web

many interconnected food chains

Herbivore

consumer that eats plants

Carnivore

consumer that eats animals

Omnivore

consumer that eats plants and animals

Primary Consumer

a consumer that eats plants

Secondary Consumer

eats the primary consumer

Tertiary Consumer

eats the secondary consumer

Producer

organisms that make their own food (plants)

Consumer

organisms that must eat things for energy (can't make their own food)

Decomposer

organisms that break down dead plants and animals

cell membrane

(P & A) surrounds and protects the cell; controls what goes in and out of the cell

cytoplasm

(P & A) jelly-like substance that fills up the space between the organelles (parts)

vacuoles

(one large in plants & and a few smaller ones in animals) sac that stores water, nutrients, or waste products

cell wall

(P only) strong outer structure that protects a plant cell and gives it support

nucleus

(P & A) contains DNA and controls the activities of the cell

mitochondria

(P & A) powerhouse of the cell; structure that converts food to energy (cellular respiration)

chloroplasts

(P only) produces energy for the cell using energy from the sun (photosynthesis!)

Cell Theory

1. All living things are made of cells
2. Cells are the smallest unit of structure & function
3. All cells come from cells

Alfred Wegener

German scientist. Proposed Continental Drift Theory.

Pangaea

Name of the supercontinent Wegener proposed.

Theory of Continental Drift

Idea that all continents were once together but have separated over time.

Tectonic Plates

Large chunks of lithosphere that cover the Earth.

Crust

Thin, solid, top layer of the Earth.

Mantle

Largest layer of the Earth. Putty-like. Convection occurs here.

Outer Core

Liquid layer of the Earth. Made of iron and nickel.

Inner Core

Hottest layer of the Earth. Solid. Made of iron and nickel.

Convergent Boundary

2 plates come together

Divergent Boundary

Plates move apart

Transform Boundary

Plates slide past each other

Hot Spot

Plates move over a source of magma.

Subduction

Movement of one plate under another.

Shield Volcano

Wide, made of flowing lava, looks like a pile of ketchup

Cinder Cone Volcano

Smallest, made of pyroclastic material

Composite Volcano

Largest volcano, explosive, made of layers of flowing lava and pyroclastic material

Seismic waves

(earthquake) waves of energy that travel through the Earth

Fault

break/crack in the Earth's crust along which an earthquake occurs

Atom

the basic unit of all matter

Element

made of all atoms of the same type; different "flavors" of atoms

Proton

positive charge

Electron

negative charge

Neutron

no charge

Atomic mass

how much the atom weighs; equal to p + n

Compound

2 or more different elements chemically combined

Mixture

physical combinations of pure substances; you can physically separate it

Pure Substance

either an element or a compound (can be written with a chemical formula); it cannot be physically separated;

Chemical Change

substances are changed into new and different substances; usually irreversible

Physical Change

substances change form but nothing new is created; usually reversible

Law of Conservation of Mass

Matter cannot be created or destroyed. The mass of your starting substances should be the same as the mass of what is produced.

Volume

how much space an object takes up

Mass

the amount of matter an object has

Length

the distance between two points

Density

mass over volume

Troposphere

layer of the atmosphere where we live

Ozone

the gas responsible for protecting us from solar radiation

Conduction

heat transfer via direct contact

Convection

heat transfer via a circulation of air or liquid

Radiation

heat transfer via waves

Evaporation

liquid water --> gas

Condensation

gas --> liquid water

Precipitation

rain, snow, hail, etc.

Run-off

water flows across the land

Humidity

the amount of water in the air

Stratus

low level cloud