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Vocabulary
A
Abdomen
The hind section of an arachnid's body that contains its reproductive organs and part of its digestive tract; the hind section of an insect's body. (p. 350)
Active Transport
The process of diffusion that requires energy.
Adaptation
A characteristic that helps an organism survive in its environment or reproduce. (pp. 149, 312)
Alga
Any simple plantlike nonvascular photosynthetic autotroph.
Allele
Each member of a gene pair that determines a specific unit.
Amoeba
A bloblike protist that uses its pseudopods to move and to obtain food.
Amphibian
Vertebrates that are fishlike and that breathe through gills when immature. They live on land and breathe through lungs and moist skin as adults. Their skin contains many glands and their bodies lack scales and claws.
Angiosperm
A plant whose seeds are contained in an ovary.
Animal
Animals are multicellular organisms with specialized tissues, and most have organs and organ systems. They are heterotrophs, and have no cell walls.
Annulus
A row of thickened cells that encircles the sporangium. (Plural annuli)
Antenna
An appendage on the head of some animals that contains sense organs. (p. 349)
Antibiotic
A chemical that destroys or weakens harmful microorganisms.
Anus
The opening at the end of an organism's digestive system through which wastes exit. (pp. 331, 529)
Arachnid
A group of arthropods such as the spider, scorpion, tick and mites. Arachnids have a body divided into two parts, a head and chest part and an abdomen. They have four pairs of walking legs.
An arthropod with only two body sections. (p. 350)
Arthropod
The three characteristics shared by all arthropods are an exoskeleton, a segmented body, and jointed appendages.
An invertebrate that has an external skeleton, a segmented body, and jointed attachments called appendages.
Asexual Reproduction
Reproduction requiring only one parent.
Autotrophs
Organisms that produce their own food.
B
Bilateral symmetry
Line symmetry; the quality of being divisible into two halves that are mirror images. (p. 316)
Bioluminescence
The production of light by a living organism. (p. 364)
Bivalve
A mollusk that has two shells held together by hinges and strong muscles. (p. 342)
Bog
A wetland where sphagnum moss grows on top of acidic water. (p. 258)
Brown alga
An alga that contains brown accessory pigments and belongs to the phylum Phaeophyta.
C
Camouflage
Protective coloration; a common animal defense. (p. 358)
Carnivore
An animal that eats only other animals. (pp. 313, 718)
Cells
The basic unit of structure and function of a living thing.
Cephalopod
A mollusk with feet adapted to form tentacles around its mouth. (p.344)
Chitin
The tough, flexible material from which arthropod exoskeletons are made. (p. 347)
Chloroplasts
Structures that contain chlorophyll; the food-making site in green plants.
Chordates
At some time during their lives, all chordates have three important characteristics: a nerve cord, a notochord, and a throat with gill slits.
Chromosomes
Rod-shaped cell structures that direct the activities of a cell and pass on traits to new cells.
Cilia
Hairlike projections on the outside of cells that move with a wavelike beat; in ciliates, cilia help these organisms to move, obtain food, and sense the environment.
Ciliate
An animallike protist that possesses cilia at some point in its life.
Circulatory System
Transports nutrients, wastes, and other materials and plays a role in the immune response.
Classification
Grouping according to similar characteristics.
Closed Circulatory System
A system in which the blood is contained within blood vessels.
Cnidarian
Animals whose stinging cells are used to capture their prey and defend themselves, and who take their food into a hollow central cavity. (p. 323)
Cold-blooded
Having a body temperature that can change somewhat with changes in the temperature of the environment.
Community
The living part of any ecosystem - all the different organisms that live together in that area.
Complete metamorphosis
A type of metamorphosis characterized by four dramatically different stages: egg, larva, pupa, and adult.
(p. 356)
Cone
In plants, a reproductive structure of a gymnosperm.
Crustacean
An Arthrop that has a hard exoskeleton, two pairs of antennae, and mouthparts that are used for crushing and grinding food.
An arthropod that has two or three body sections, five or more pairs of legs, two pairs of antennae, and usually three pairs of appendages for chewing. (p. 349)
Cuticle
The waxy, waterproof layer that covers the leaves and stems of some plants. (p. 249)
D
Decomposer
An organism that breaks down dead organisms into simpler substances, thereby returning important materials to
the soil and water.
Diatom
A plantlike protist that has a beautiful two-part glassy shell.
Diffusion
Process by which materials enter and leave a cell through the cell membrane.
Dinoflagellate
A plantlike protist that typically has cell walls that look like plates of armor and possesses two flagella, one of
which trails from one end like a tail and the other of which wraps around the middle of the organism like a belt.
Dominant
Trait that is expressed when two different genes for the same trait are present; "stronger" of two traits.
E
Echinoderm
Animals that have a spiny skin, an internal skeleton, a five-part body, a water vascular system, and structures called tube feet.
Ecology
The study of the relationship and interactions of living things with one another and with their environment.
Ecosystem
A unit consisting of all the living and nonliving things in a given area that interact with one another.
Ectothermic
An animal (Example: reptiles) that must absorb heat from the environment because their metabolism is too slow to produce enough heat to warm their bodies.
Endocrine System
Plays a part in the regulation of metabolism, reproduction, and many other functions.
Endoskeleton
An internal skeleton. (p. 365)
Endothermic
The ability of an animal (mammals and birds) to maintain a high, constant body temperature because they produce heat internally through a faster metabolism.
Environment
All the living and nonliving things with which an organism may interact.
Euglena
A plantlike flagellate protist that belongs to the genus Euglena and is characterized by a pouch that holds two flagella, a reddish eyespot, and a number of grass-green chloroplasts that are used in photosynthesis.
External Fertilization
Process in which a sperm joins with an egg outside the body.
Exoskeleton
Rigid outer covering in most arthropods. An outer skeleton. (p. 347)
F
Feeding Level
The location of an organism along a food chain.
Fern
Green plants, Ferns and their relatives share two characteristics. They have vascular tissue and use spores to
reproduce.Most ferns have underground stems in addition to underground roots. The leaves, or fronds, grow
above ground. (p. 263)
Fertilization
The joining of a sperm cell and an egg cell. (pp. 252,663)
Flagellum
A long whiplike structure that propels a cell through its environment.
Flower
A reproductive structure of an angiosperm.
Food Chain
Represents a series of events in which food and energy are transferred from one organism in an ecosystem to another.
Food Web
Consists of many overlapping food chains.
Frond
The green leaf of a fern plant. Fronds are divided into many smaller parts that look like small leaves. Spores are
produced on the undersides of mature fronds. (p. 264)
Fruit
A ripened ovary of a plant that encloses and protects the seed or seeds.
Fungus
A heterotroph, usually multicellular, that releases chemicals that digest the substance on which it is growing and then absorbs the digested food; multicellular fungi are made up of threadlike hyphae; many fungi reproduce by means of spores.
G
Gamete
A sperm cell or an egg cell. (p. 253)
Gametophyte
The stage in the life cycle of a plant in which the plant produces gametes, or sex cells. (p.253)
Gastropod
A mollusk with a single shell or no shell. (p. 342)
Geneotype
Gene makeup of an organism.
Genes
Units of heredity; segments of DNA on chromosomes.
Genetic Engineering
The transfer of a gene from the DNA of one organism into another organism, in order to produce an organism
with desired traits. (p. 134)
Genetics
Study of heredity, or the passing on of traits from an organism to its offspring.
Gestation Period
Time the young of placental mammals spend inside the mother.
Gill
An organism's breathing organ that removes oxygen from water. (p. 341)
Feathery structure through which water-dwelling animals breathe.
Gradual metamorphosis
A type of metamorphosis in which and egg hatches into a nymph that resembles an adult, and which has no distinctly different larval stage. (p. 356)
Green Alga
An alga that gets its color from the green pigment chlorophyll and belongs to the phylum Chlorophyta.
Gymnosperm
A plant whose seeds are not contained in an ovary.
H
Herbivore
An animal that eats only plants. (pp.312, 718)
Heterotrophs
Organisms unable to make their own food.
Homeostasis
An organisms' ability to maintain a constant body temperature even though conditions in its external
environment change.
Hybrid
Organism that has two different genes for a trait, or that combines traits of two different but related species.
Hypha
One of the branching, threadlike tubes that makes up the body of a multicellular fungus.
I
Incomplete Dominance
Condition in which neither of the two genes in a gene pair masks the other.
Ingestion
The process of eating.
Insect
Organisms having a body that is divided into three parts, a head, a chest, and an abdomen, and that has three pairs of legs attached to the chest part.
An arthropod with three body sections, six legs, one pair of antennae, and usually one or two pairs of wings. (p. 355)
Internal Fertilization
Process in which a sperm joins with an egg inside the body.
Invertebrate
An animal that does not have a backbone. (pp. 313)
J
K
Kidney
A major organ of the excretory system; eliminates urea, excess water, and other waste materials from the body. (pp. 341, 581)
L
Larva
The immature form of an animal that looks very different from the adult. (p. 322)
Leaf
A structure in vascular plants whose main function is typically photosynthesis.(p. 278)
Lichen
A plantlike structure that is formed by a fungus and an alga that live together.
Lipids
Scientific term for fats and oils.
M
Mammals
Warm-blooded vertebrates that have hair or fur and that feed their young with milk produced in mammary glands.
Medusa
The cnidarian body plan characterized by a bowl shape and which is adapted for a free-swimming life. (p. 324)
Meiosis
Process of cell division in which sex cells (sperm and egg) are produced.
Metabolism
All chemical activities in an organism.
Metamorphosis
A proces in which an animal's body undergoes dramatic changes in form during its life cycle. (p. 350)
Migrate (Migration)
To move to a new environment during the course of a year.
Mitosis
The process by which the nucleus of a cell divides into two nuclei and the formation of two new daughter cells
begins.
Mold
A fuzzy, shapeless, fairly flat multicellular fungus.
Mollusk
An invertebrate with a soft, unsegmented body; most are protected by hard outer shells. (p. 340)
Molting
The process of shedding an outgrown exoskeleton. (p. 348)
Moneran
Tiny organisms that consist of a single cell, and lack a nucleus as well as certain other cell structures.
Moss
The most diverse group of nonvascular plants (over 10,000 species). (p. 257)
Moss Life Cycle
Mushroom
A multicellular fungus shaped like an umbrella.
N
Niche
The role an organism plays in a community. It consists of everything the organism does and everything the organism needs in its environment.
Nonvascular Plant
A low-growing plant that lacks vascular tissue. (p. 256)
Nucleus
The "brain" or control center of the cell.
Nymph
A stage of gradual metamorphosis that usually resembles the adult insect. (p. 356)
O
Omnivore
An animal that eats both plants and animals. (pp. 313, 718)
Open Circulatory System
A system in which the blood is not contained within blood vessels. Example: arthropods.
Organ
A structure in the body that is composed of different kinds of tissues. (pp. 311, 475)
Organelles
Structures that make up a cell.
Osmosis
Diffusion with water.
Ovule
A structure in a female cone or flower that contains an egg's cell and develops into a seed.
P
Paramecium
A slipper-shaped ciliate protist that belongs to the genus Paramecium.
Permeable
Allowing any material to pass through.
Peat
The blackish-brown material consisting of compressed layers of dead sphagnum mosses that gro in bogs.
(p. 258)
Petal
A colorful leaflike flower structure that serves to attract pollinators.
Phenotype
Physical characteristics.
Pheromone
Powerful chemical given off by an insect to attract a mate.
Phloem
Plant vascular tissue that carries food.
Photosynthesis
Process by which organisms use energy from the sun to make their own food.
Pistil
A female reproductive organ in a flower, which consists of a stigma, style, and ovule-containing ovary.
Pollen
Tiny grains that can be thought of as containing sperm cells, which are produced by male cones and flowers.
Pollination
The process by which pollen is carried from male reproductive structures to female reproductive structures.
Polyp
The cnidarian body plan characterized by a vaselike shape and which is usually adapted for life attached to an underwater surface. (p. 323)
Population
A group of organisms of the same type, or species, living together in the same area.
Predator
A carnivore that hunts and kills other animals for food and has adaptations that help it capture the animals it preys upon. (pp. 313, 706)
Prey
An animal that a predator feeds upon. (pp. 313, 706)
Protists
A unicellular organism that contains a nucleus.
Pseudopod
A temporary extension of the cell membrane and cytoplasm used in feeding and/or movement.
Pupa
The second stage of complete metamorphosis, in which an insect is enclosed in a protective covering and gradually changes from a larva to an adult. (p. 356)
Q
R
Radial symmetry
The quality of having many lines of symmetry that all pass through a central point. (p. 316)
Radula
A flexible ribbon of tiny teeth in mollusks. (p.341)
Recessive
Trait that seems to disappear when two different genes for the same trait are present; "weaker" of the two traits.
Red Alga
An alga that contains red accessory pigments and belongs to the phylum Rhodophyta.
Regeneration
The ability of an organism to regrow body parts. (p. 328)
Reptiles
Cold-blooded vertebrates that have lungs, scaly skin, and a special type of egg.
Respiration
Process by which living organisms take in oxygen and use it to produce energy.
Respiratory System
Exchanges oxygen and carbon dioxide between blood and air.
Response
Some action or movement of an organism caused by a stimulus.
Rhizoid
The thin, rootlike structure that anchors a moss and absorbs water and nutrients for the plant. (p. 257)
Root
A structure in vascular plants whose main functions are typically absorption and anchorage. Roots anchor a plant in the ground and absorb water and nutrients from the soil. (p. 282)
S
Sarcodine
An animallike protist that possesses pseudopods.
Scavenger
An animal that feeds on the bodies of dead animals.
Sepal
A leaflike structure that protects a developing flower.
Slime mold
A funguslike protist that is a microscopic amoebalike cell at one stage of its life cycle and a large, moist, flat, shapeless blob at another stage; slime molds produce reproductive structures known as fruiting bodies, which contain spores.
Species
A group of similar organisms that can produce offspring.
Sponges
The simplest group of invertebrates with a body covered with many pores, or tiny openings.
Sporangium
The tiny spore cases that grow on the undersides of fern fronds. (Plural sporangia)
Spore
A cell, usually surrounded by a protective wall, that is specialized either for reproduction or for a resting
stage; the reproductive cells produced by most fungi. A tiny cell that is able to grow into a new organism.
(p. 223)
Sporophyte
The stage in the life cycle of a plant in which the plant produces spores for reproduction. (p. 253)
Sporozoan
A parasitic animallike protist that has a complex life cycle involving more than one kind of host animal and that typically produces cells called spores in order to pass from one host to another.
Stamen
A male reproductive organ in a flower, which consists of a filament topped by a pollen-producing anther.
Stem
A structure in vascular plants whose main functions are typically to carry materials between the roots and
leaves and to support the plant.(p. 280)
Stimulus
Signal to which an organism reacts.
Symbiosis
A relationship in which one organism lives on, near, or even inside another organism and at least one of the organisms benefits.
T
Taxonomy
The science of classification.
Territory
Area where an individual animal lives.
Thorax
An insect's mid-section, to which its wings and legs are attached. (p. 355)
Tissue
A group of similar cells that perform a specific function in an organism. (p.252, 474)
Trait
Physical appearance
Tropism
In plants, the growth of a plant toward or away from a stimulus.
U
Unicellular
One celled.
V
Vascular plant
A plant that has vascular tissue.
Vascular Tissue
The internal transporting tissue in some plants that is made up of tubelike structures. (p. 252)
Vertebrate
The bones that make up the backbone of an animal. (pp. 375, 481)
W
Water Vascular System
A system of fluid-filled tubes in an echinoderm's body. (p. 366)
X
Xylem
Plant vascular tissue that carries water and minerals from the roots up through a plant and that also helps to support a plant.
Y
Yeast
A unicellular fungus.
Z
Zooflagellate
An animallike protist that possesses flagella.
Zygote
A fertilized egg, produced by the joining of a sperm and an egg. (p. 252, 663)
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