# 1st semester 7th grade science exam study guide completed

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Sunset middle school, brentwood Ms. Grunwald 2012-2013 orange team class.

find something to research

### 2. Make observations

make observations on the topic (collect data on the topic [research])

### 3. Form a hypothesis

make if then statement using inferences from the observations made that gives a possible explanation (answer) to the question.

### 4. Test the hypothesis

design experiments that will clearly show whether a particular factor caused an observed outcome.

### 5. Analyze the results

organize your data and analyze the results.

### 6. Draw conclusions

decide whether your hypothesis was correct or not and explain why or why not. If your hypothesis is wrong try to come up with another possible solution and repeat steps 2-7.

### 7. Communicate Results

let other scientist know of your results. A wrong hypothesis is just as useful as a right hypothesis because either way it allows scientist to learn. If it doesn't work it is useful if everyone knows that because people won't have to repeat the experiments and they then can work together to find the answer. Also by telling people what you did, they can repeat the experiments and see if they get the same results.

### Scientific Methods

a series of steps followed to solve problems

### Observation

any information you gather through your senses.

### Inference

a logical interpretation of an event that is based observations and prior knowledge.

### Control Factors

The parts of the experiment that will remain the same. An example is 100 eggs.

### Variables

There are two types of variables: The independent and dependent variable.

### Independent variable

The variable that is controlled by the scientist.

### Dependent variable.

the variable that might change because of what the scientist changes

### Prototype

a test model of a product

### Cost

benefit analysis - the process of determining whether the cost of doing something is worth the benefit provided.

### Scientist

anyone who study's science.

### Engineers

engineers use science and mathematics to create new technologies that serve human needs.

### Engineering design process

the process engineers use to develop a new technology.

### Intended benefits

An intended benefit is the positive purpose for which a technology is designed to be used.

### Unintended benefits

Unintended consequences are uses or results that engineers do not purposely include in the design of products.

### Example: the ability for people to have food not native to the area was an unintended benefit of a refrigerator.

unintended benifits

### Assistive bioengineering

engineering that results in a product or process that helps living organisms but does not change them permanently.

### Example: crutches.

Assistive bioengineering

engineering that results in a product or process that changes living organisms.

### Cells

the smallest living things on the levels of organization of living things.

### Tissues

a group of similar cells that perform a common function.

muscles

### Organ

a collection of tissues that carry out a specialized function of the body.

a organ

### Organ system

a group of organs that work together to perform body functions.

a organ system

### Organism

a living thing; anything that can carry out life processes independently.

an organism

### Prokaryotic cell

a single-celled organism that does not have a nucleus or membrane-bound organelles; examples are Achaea and bacteria.

### Eukaryotic cell

an organism made up of cells that have a nucleus enclosed by a membrane; eukaryotes include protists, animals, plants, and fungi but not Achaea or bacteria.

### Longer life

a benifit of being multicellular

### Specialization

a benifit of being multicellular

### Bigger size

a benifit of being multicellular

### Nucleus

In a eukaryotic cell, a membrane-bound organelle that contains the cell's DNA and that has a role in processes such as growth, metabolism, and reproduction.

### Nucleolus

Found inside the nucleus and produces ribosomes.

### Ribosomes

Cell organelle composed of RNA and protein; the site of protein synthesis.

### Lysosomes

The organelle that digests food particles, wastes, cell parts, and foreign invaders.

### Chloroplasts

The organelle that uses the energy of sunlight to make food.

### Mitochondria

The organelle that breaks down food molecules to make ATP (energy).

### Endoplasmic Reticulum

The organelle that makes lipids, breaks down drugs and other substances, and packages proteins for Golgi complex.

### Golgi complex

The organelle that processes and transports proteins and other materials out of the cell.

### Chromosomes

One of the structures in the nucleus that is made up of DNA and protein.

### Cell Membrane

Controls what comes into and out of the cell; found in plant and animals cells.

### Cell Wall

The rigid structure that surrounds the cell membrane and provides support to the cell.

### Cytoskeleton

A web of proteins in the cytoplasm that acts as both muscle and a skeleton and keeps the membrane from collapsing and helps some cells move.

### Cytoplasm

The gel-like fluid where the organelles are found and it is inside the membrane.

### Vesicles

Small sacs that surrounds materials to be moved into or out of a cell.

### Large Central Vacuole

The organelle that stores water, wastes, food, and other materials. It is only found in plant cells.

### Interphase

the cell prepare for mitosis and copy's all its organelles, chromosomes, and grows.

### Growth Phase One

the cell grows and does its job.

### Synopsis

chromosomes are copied.

### Growth Phase Two

the cell's organelles are replicated.

### Mitosis

a process of cell division that produces two identical nuclei.

### Prophase

Mitosis begins and chromosomes condense from long strands into rod like structures.

### Metaphase

The nuclear membrane is dissolved and paired chromatids align at the cell's equator.

### Anaphase

The chromatids separate and move to opposite sides of the cell.

### Telophase

A nuclear membrane forms around each set of chromosomes, and the chromosomes unwind and mitosis is complete.

### Cytokinesis

In cells that lack a cell wall, the cell pinches in two. In cells that have a cell wall, a cell plate forms between the two new cells. Then the cells separate.

### Chromosomes

in a eukaryotic cell, one of the structures in the nucleus that are made up of DNA and protein; in a prokaryotic cell, the main ring of DNA.

### Chromatin

chromosomes in their thread like state.

### Chromatid

chromosomes in their rod like state.

### Diffusion

movement of particles from an area of high concentration to an area of lower concentration.

### Osmosis

the diffusion of molecules through a semipermeable membrane from a place of higher concentration to a place of lower concentration until the concentration on both sides is equal.

### Endocytosis

the process by which a cell membrane surrounds a particle and encloses the particle in a vesicle to bring the particle into the cell.

### Exocytosis

the process in which a cell releases a particle by enclosing the particle in a vesicle that then moves to the cell surface and fuses with the cell membrane.

### Passive Transport

the movement of substances across a cell membrane without the use of energy by the cell.

### Active Transport

the movement of substances across the cell membrane that requires the cell to use energy.

### Equilibrium

point at which the number of diffusing molecules moving in one direction is equal to the number moving in the opposite direction.

### Selectively Permeable Membrane

a membrane that allows only certain molecules to pass through it by diffusion.

### Photosynthesis

the process by which plants, algae, and some bacteria use sunlight, carbon dioxide, and water to make food. The products of photosynthesis are oxygen and glucose. The reactants of photosynthesis are carbon dioxide, water, and sunlight.

### Cellular Respiration

the process by which cells use oxygen to produce energy from food. The products of cellular respiration are carbon dioxide and energy. The reactants of cellular respiration are oxygen and glucose.

### Chloroplast

where photosynthesis takes place.

### Chlorophyll

the process by which cells use oxygen to produce energy from food.

### Mitochondria

the cell organelle that is surrounded by two membranes and that is the site of cellular respiration. It is called the powerhouse of a cell.

### The Carbon Cycle

The continuous process by which carbon is exchanged between organisms and the environment.

### Combustion

The process of the carbon in oil, coal, and natural gas returning to the atmosphere as carbon dioxide when burned.

### Decomposition

the breaking down of dead materials into carbon dioxide and water.

### Photosynthesis

The process by which plants, algae, and some bacteria use sunlight, carbon dioxide, and water to make food.

### Respiration

the process by which you inhale oxygen and exhale carbon dioxide.

### Fossil Fuels

fuels that are formed from the remains of prehistoric plant and animal life.

Example: