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Grade 7 Science Review

STUDY
PLAY
Cilia
short thin hair-like structures on outside of microorganisms; helps cells move
Flagellum
tail-like extensions of cells in some microorganisms; helps cells move
Pseudopod
means 'false foot' and are tiny extensions of cell cytoplasm used for movement and feeding
Protists
unicellular that get food from other organisms
Chlorophyll
A green photosynthetic pigment found in the chloroplasts of plants algae and some bacteria
Cell Membrane
controls which substances can enter or leave the cell
Cell Wall
a rigid layer that surrounds the cells of plants
Nucleus
organelle in some cells, which contains the genetic information (DNA) of the cell; provides the cell with directions for how to perform
Microscope
object used to increase the visual size of an object so it can be more easily observed
Chloroplast
captures energy from sunlight and uses it to produce food in plant cells
Mitochondria
produce most of the energy needed to carry out the cell's functions
Vacuoles
a water-filled sac inside a cell that acts as a storage area
Cell
the basic unit of structure and function in living things
Tissue
A group of similar cells that perform a specific function
Organ
A collection of tissues that carry out a specialized function of the body
Organ System
Group of organs that work together to perform a specific function
Organism
A living thing
Mechanical digestion
physically breaking food into smaller pieces
Chemical digestion
breaking food down with enzymes and acid
Ureter
duct that connects kidney to bladder
Urethra
duct that moves urine outside of the body from the bladder
Ovary
female reproductive organ that contains the eggs
Kidneys
bean-shaped organs in the excretory system - help filter blood to maintain a balance of solutes and water in the bloo
Bronchial tubes
air passage that connect to the trachea and the lungs by branching off
Lungs
major organ of the respiratory system filled with tiny air-sacs which fill with O2-rich air during inhalation and push out CO2 during exhalation
Trachea
tube extending from the mouth to the bronchi
Liver
creates bile (which is secreted by the gall bladder to the small intestine) which helps digest and absorb fats
Pancreas
organ behind the stomach that secretes insulin
Heart
major organ of the circulatory system muscular pump with 4 chambers which transports blood to the lungs and body
Arteries
brings oxygenated blood from the heart to the body
Veins
brings deoxygenated blood from the body to the heart
Capillaries
tiny, hair thin tubes that bring blood to cells in the body
White blood cells
cells that phagocytize (eat) foreign invaders
Red blood cells
cells which carry oxygen in the blood stream - they get their color from iron in the protein hemoglobin, which holds the O2 inside the cells
Respiration
action of breathing in which chemical energy is transformed into energy usable by the body for growth and repair
Fertilization
The process in sexual reproduction in which male and female reproductive cells (gametes) join to form a new cell
Esophagus
transports food from the mouth to the stomach
Gallbladder
small organ which stores bile
Asexual
Produces genetically IDENTICAL offspring from a SINGLE parent
Sexual
Produces genetically DIFFERENT offspring which inherit genetic information from TWO parents
Zygote
one cell that has both female and male reproductive cell
DNA
(deoxyribonucleic acid) a complex molecule containing the genetic information that makes up the chromosomes. It's shape is in the form of a Double Helix.
Mitosis
A nuclear division resulting in the production of two somatic cells having identical genetic material as the original cell
Prokaryote
"before nucleus" - organisms that do not have an enclosed nucleus
Meiosis
A type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes
Sex Cells
sperm and egg
Cell Division
division of a cell into daughter cells
Eukaryote
"true nucleus" - organisms that contain an enclosed nucleus
Binary Fission
When an organism splits into an exact copy
Allele
different forms of a gene
Gene
Sequence of genetic coding given to an offspring from their parents
Genotype
letters that represent the set of alleles that an individual has for a trait
Phenotype
the physical appearance of a trait
Punnett Square
chart to show possible allele combinations
Dominant Trait
the gene that is expressed (capital letter)
Recessive Trait
a gene (or allele) whose phenotypic expression (physical appearance) is MASKED by a dominant gene.
Chromosome
A threadlike structure found in the nucleus containing genetic information. Each chromosome consists of one very long DNA molecule and associated proteins
Homozygous
same alleles
Heterozygous
different alleles
Heredity
The passing of traits from parents to offspring
Genetics
The scientific study of heredity
Mendel
father of genetics who studied pea plants
Amoeba
unicellular organism that moves via pseudopods
paramecium
unicellular organisms that moves with cilia and are found in fresh water
euglena
unicellular organisms with flagellum that are found in salt and fresh water
volvox
unicellular organisms that live in colonies up to 50,000 cells; known as algae and moves with flagellum
digestive system
converts food into molecules used by the body; eliminates wastes
excretory system
Removes waste from the body and filters blood
ciculatory system
Pumps blood, distributes nutrients and oxygen and removes CO2 from the body
respiratory system
exchanges O2 and CO2 through inhalation and exhalation
integumentary system
"skin" that surrounds and protects the body
nervous system
controls body functions and maintains homeostasis by directing all the other organ systems
reproductive system
produces eggs and sperm - enables sexual reproduction