Science 7 Final Exam Study Guide Flashcards

A comprehensive set of vocabulary flashcards covering the scientific method, cell biology, genetics, human body systems, and basic biological processes from the Science 7 final exam study guide.

Hypothesis

An educated guess or prediction about what will happen, often in the form "If I do [this], then [that] will happen."

Independent Variable

The factor that is changed in an experiment, also known as the manipulated variable.

Dependent Variable

The factor that is observed or measured in an experiment, also known as the responding variable.

Controlled Variable

The factors that are kept the same in an experiment to ensure a fair comparison.

Qualitative Observation

Observations made using the senses, such as color or size.

Quantitative Observation

Observations that can be measured, such as mass, height, or density.

Robert Hooke

The scientist who looked at cork under a microscope and first named the structures "cells."

Anton Van Leeuwenhoek

The first person to see living cells under a microscope using a sample of pond water.

Cell Theory

1. All living things are made from one or more cells. 2. Cells can only come from other cells. 3. The cell is the basic unit of life.

Prokaryotic

A type of cell that does not have a nucleus.

Eukaryotic

A type of cell that contains a nucleus.

Cell

The smallest unit that can carry out life's activities.

Tissue

A group of cells working together to perform a specific job.

Organ

A group of tissues working together to perform a specific job.

Organ System

A group of organs working together to perform a specific job.

Organism

A living thing that can be made of one cell or many organ systems.

Cell Wall

A rigid, tough structure made of cellulose that protects and supports plant cells.

Cell Membrane

A thin covering that protects the cell, performs transport, and moves materials in and out.

Cytoplasm

A jelly-like substance that contains organelles and supports them inside the cell.

Nucleus

A dense, ball-shaped structure containing DNA that controls all of the cell’s activities.

Endoplasmic Reticulum

A clear, tubular system of tunnels that transports materials like proteins around the cell.

Ribosome

Small specks made of RNA, found in the cytoplasm or on the ER, that make proteins.

Mitochondria

Bean-shaped organelles in the cytoplasm that supply energy or $ATP$ through cell respiration using glucose and oxygen.

Vacuole

A large open storage area for food, water, wastes, or enzymes; smaller in animal cells.

Chloroplast

Green structures in plants containing chlorophyll that capture sunlight for photosynthesis.

Golgi Body

Small bags with connecting tubes that package and secrete proteins for use in and out of the cell.

Lysosome

Small, round structures containing enzymes that digest older cell parts, food, or other objects.

Centriole

Small cylindrical structures used with the spindle apparatus during mitosis in animal cells.

Diffusion

The passive transport of small particles from an area of high concentration to an area of low concentration.

Osmosis

The diffusion of water from a high concentration to a low concentration across a cell membrane.

Active Transport

The movement of small particles from low concentration to high concentration, which requires energy.

Heredity

The transmission of characteristics from parents to offspring.

Phenotype

The physical characteristic of an organism.

Genotype

The genetic make-up or genes of an organism.

Alleles

Different forms of a gene, usually occurring in pairs.

Dominant Allele

An allele more likely to be expressed, represented by a capital letter.

Recessive Allele

An allele least likely to be expressed, represented by a lower case letter.

Homozygous Dominant

Having two dominant alleles ($AA$).

Homozygous Recessive

Having two recessive alleles ($aa$).

Heterozygous

Having one dominant and one recessive allele ($Aa$).

Incomplete Dominance

A cross between organisms with different phenotypes that produces offspring with a blending of parental traits.

Codominance

A cross where both parental traits appear together in the offspring's phenotype.

Watson and Crick

The scientists who first discovered DNA and modeled it as a double helix.

DNA Nucleotide

The building block of DNA consisting of deoxyribose sugar, a phosphate group, and a nitrogenous base.

Base Pairing Rule

The rule that Adenine pairs with Thymine ($A=T$) and Guanine pairs with Cytosine ($G=C$).

Arteries

Blood vessels with thick, elastic walls that carry oxygen-rich blood away from the heart.

Veins

Blood vessels that carry oxygen-poor blood back to the heart and contain valves.

Capillaries

Blood vessels only one cell layer thick that allow nutrient and waste exchange at the cellular level.

Alveoli

Tiny sacs in the lungs surrounded by capillaries for $CO_2$ and $O_2$ exchange.

Diaphragm

A dome-shaped muscle below the lungs that contracts to pull air in and expands to push air out.

Peristalsis

Muscular contractions that move materials through the digestive tract.

Bile

A substance made by the liver to aid the small intestine in breaking down fats.

Nephrons

The filtering units in the kidneys.

Ligaments

Tough connective tissue that holds joints together.

Cartilage

A material at the ends of bones that reduces friction; also found in the ear and nose.

Dichotomous Key

A tool used to identify organisms by presenting two choices based on characteristics at each step.

Photosynthesis

The process where plants use solar energy to convert $CO_2$ and water into oxygen and sugars.

Respiration

The process in which cells break down sugars to release energy, converting glucose and oxygen into $CO_2$ and water.