Biology- Diversity of Living Things P2

Bryophytes

Non-vascular plants including mosses, liverworts, and hornworts.

Vascular tissue

Tissue that transports water and nutrients through a plant.

Rhizoids

Small root-like structures that anchor bryophytes; they are not true roots.

Diffusion

Movement of particles from an area of higher concentration to lower concentration.

Osmosis

Movement of water across a selectively permeable membrane.

Sporic reproduction

A life cycle alternating between a gametophyte and a sporophyte.

Gametophyte

Haploid generation that produces gametes by mitosis.

Sporophyte

Diploid generation that produces spores by meiosis.

Haploid

Having one set of chromosomes (n).

Diploid

Having two sets of chromosomes (2n).

Mitosis

Cell division that produces genetically similar cells.

Meiosis

Cell division that produces haploid cells.

Seedless vascular plants

Plants with vascular tissue that reproduce using spores instead of seeds.

Gymnosperm

A vascular plant with exposed, non-enclosed seeds, often on cone scales.

Angiosperm

A flowering vascular plant whose seeds are enclosed in protective tissue.

Conifers

Cone-bearing gymnosperms such as pine, spruce, and cedar.

Cone

Gymnosperm reproductive structure containing male or female reproductive parts.

Pollen grain

Structure containing the reduced male gametophyte that transports sperm cells or nuclei.

Pollination

Transfer of pollen to a female reproductive structure.

Flower

Angiosperm reproductive structure used for sexual reproduction.

Fruit

Mature flower ovary that protects and helps disperse seeds.

Fungi

Eukaryotic heterotrophs with cell walls containing chitin that absorb digested nutrients.

Chitin

Strong material found in fungal cell walls.

Hyphae

Thread-like filaments forming the body of most multicellular fungi.

Hypha

A single thread-like fungal filament.

Mycelium

Branching network of fungal hyphae.

Fruiting body

Visible reproductive structure that produces fungal spores.

External digestion

Breaking down food outside the organism's cells using digestive enzymes.

Parasitic fungi

Fungi that absorb nutrients from living host organisms.

Predatory fungi

Soil fungi that trap and consume prey.

Mutualistic fungi

Fungi that benefit from partnerships with other organisms.

Mycorrhiza

Mutualistic relationship in which fungal mycelia associate with plant roots; fungi receive sugar and plants gain improved nutrient absorption.

Saprobe

An organism that feeds on dead organisms or organic waste.

Saprobial fungi

Decomposer fungi that absorb nutrients from dead or decaying matter.

Budding

Asexual reproduction in which a smaller individual grows from a parent cell.

Fragmentation

Asexual reproduction in which a piece of an organism grows into a new individual.

Spore

A reproductive cell that can develop into a new organism under suitable conditions.

Heterotroph

An organism that obtains nutrients from other organisms or organic matter.

Eukaryote

An organism whose cells contain a nucleus.

Animal kingdom

Kingdom of multicellular eukaryotic heterotrophs whose cells lack cell walls.

Invertebrate

An animal without a backbone.

Vertebrate

An animal with a backbone.

Tissue

A group of similar cells specialized to perform a particular function.

Organ

A structure made of tissues working together for a function.

Organ system

A group of organs working together to perform major functions.

Ectoderm

Outer embryonic cell layer; forms skin and nervous tissue.

Mesoderm

Middle embryonic cell layer; forms muscles, blood, kidneys, and reproductive organs.

Endoderm

Inner embryonic cell layer; forms the lining of the stomach and contributes to organs such as the lungs and liver.

Asymmetry

An irregular body plan that cannot be divided into equal halves along a consistent plane.

Radial symmetry

Body arrangement in which similar halves can be formed along multiple planes through a central axis.

Bilateral symmetry

Body arrangement that can be divided into mirror-image halves along one plane.

Coelom

Fluid-filled body cavity containing or surrounding internal organs.

Coelomate

An animal that has a coelom.

Acoelomate

An animal that lacks a coelom.

Segmentation

Division of the body into repeated sections called segments.

Sessile

Stationary; attached to one place rather than moving freely as an adult.

Gametic reproduction

Sexual reproduction in which the organism is diploid and the eggs and sperm are haploid.

Zygote

Diploid cell formed when an egg and sperm unite.

External fertilization

Fusion of egg and sperm outside the body.

Internal fertilization

Fusion of egg and sperm inside the female's body.

Worms

Animals including flatworms such as planarians, tapeworms, and flukes; some are parasitic and some are free-living.

Chordata

Animal phylum characterized by features including a notochord and a dorsal nerve cord at some stage of development.

Notochord

Rod-shaped supporting structure extending along the body of a chordate embryo.

Dorsal nerve cord

Tube-shaped nerve structure along the back; in vertebrates it develops into the brain and spinal cord.

Tetrapods

Vertebrates descended from four-limbed ancestors, including amphibians, reptiles, birds, and mammals.

Fish

Aquatic vertebrates that use gills to obtain dissolved oxygen from water.

Gills

Organs that extract dissolved oxygen from water.

Cartilage

Flexible supporting tissue forming the skeleton of sharks and rays.

Bony fish

Fish with skeletons made primarily of bone.

Swim bladder

Gas-filled organ that helps most bony fish control their position in water.

Amphibians

Tetrapods that generally have moist skin, often use their skin for gas exchange, and commonly reproduce externally.

Gas exchange

Movement of gases, such as oxygen and carbon dioxide, between an organism and its environment.

Reptiles

Vertebrates with waterproof scales, lungs, internal fertilization, and typically amniotic eggs.

Amniotic egg

Egg with protective membranes that help the embryo develop on land.

Birds

Feathered, endothermic vertebrates with lungs connected to air sacs and lightweight adaptations for flight in most species.

Air sacs

Structures connected to bird lungs that support one-way airflow through the respiratory system.

Mammals

Endothermic vertebrates characterized by hair and mammary glands that produce milk.

Mammary glands

Glands that produce milk to nourish developing young.

Endothermic

Able to maintain body temperature primarily through internal heat production.

Monotremes

Egg-laying mammals, such as the platypus.

Marsupials

Mammals whose young typically develop further in a pouch after birth, such as kangaroos and koalas.

Placental mammals

Mammals whose young develop in the uterus with support from a placenta; examples include humans and polar bears.

Placenta

Organ that allows exchange of nutrients, gases, and wastes between a pregnant mammal and its developing offspring.