Science 8 4th Periodical Exam Reviewer

Species

defined as a group of organism that can be interbreed and produce healthy and fertile offspring

Taxonomy

Branch of Biology that deals with the hierarchical classification of organisms based on their shared characteristics

Carl Linnaeus

Swedish botanist, is recognized as the “Father of Taxonomy”

Binomial nomenclature

An organism is given a scientific name that consists of its genus and species name in Latin

Domain

Highest taxonomic rank of organisms as proposed by the American microbiologist and biophysicist Carl Woese and Company in 1990

Carl Woese

American microbiologist and biophysicist

Three Domains

• Bacteria

• Archaea

• Eukarya

Kingdom

• The next highest level of classification

• six widely accepted kingdoms namely Archaea, Bacteria, Protista, Fungi, Plantae, and Animalia

Archaea

unicellular prokaryotic organisms that are distinct from bacteria in key biochemical make up and metabolic reaction

Bacteria

unicellular prokaryotic organisms

Protists

Highly diverse organisms that can have plant-like or animal-like characteristics

Fungi

have cell wall made up of chitin and are heterotrophic in nature

Plants

eukaryotic photosynthetic organisms with cell wall that is made up of cellulose fibers

Animals

are eukaryotic heterotrophic organisms that depend on plants and other organisms for nourishment

Non-vascular plants

known as bryophytes

Gametophyte

haploid sexual phase

Sporophyte

diploid stage

Liverworts

belong to division marchantiophyta

Hornworts

smallest group of bryophytes

Mosses

largest group of bryophytes

Vascular plants

also known as tracheophytes

Xylem

carries water from roots to the shoots

phloem

transports sugar from the leaves to other parts of the plant

Seedless vascular plants

known as pteridophytes

Ferns

form the bulk of pteridophytes

Horsetails

belong to class Equisetopsida

Lycophytes

belong to division Lycopodiophyta

Seed-bearing plants

produce seeds and they are further subdivided into two phyla:

• The Gymnosperm

• Angiosperm

Gymnosperms

have naked or exposed seeds

Conifers

• belong to division Pinophyta

• largest group of gymnosperms

Cycads

slow growing and love-living gymnosperms belonging to division Cycadophyta

Gingko

genus of gymnosperms

deciduous plant

means that it shed-off its leaves periodically turning into bright yellow color before falling off

Angiosperms

bear flowers and have seeds enclosed in a fruit

Monocotyledons

simply monocots, have seed in one cotyledon, fibrous root system

Dicotyledons

simply dicots, have seed in two cotyledons

Poriferans

commonly known as sponges

Echinoderms

radially asymmetric marine animals with up to 7000 species

Sea cucumbers

which belong to the class Holothuroidea

Starfishes

sea stars belong to class Asteroidea

Sea urchins

are globular and spiny echinoderms belonging to class Echinodea

Brittle stars

belong to class Ophiuroidea and have five long slender arms

Cnidarians

stinging aquatic animals with at least 10000 species

Nematocysts

often contains poison to ward off predators and capture preys

Corals

belong to class Anthozoa

Sea anemones

belong to class Anthozoa like corals

Jellyfish

swimming gelatinous medusa that belong to subphylum Medusozoa

Mollusks

soft-bodied invertebrates with around 85,000 known species

Gastropods

the most numerous with at least 60,000 known species that live in water, on land, or both.

Bivalves

freshwater or marine mollusks enclosed by two hinged shells which is made up of calcium carbonate

Cephalopods

are mollusks with tentacles

Annelids

known as segmented or ringed worms

Earthworms

burrowing segmented worms that feed on detritus or decaying organic matter

Leeches

either parasitic or predatory segmented worms belonging to class Clitellata and subclass Hirudinea

Nematodes

round worms with around 25,000 known species

Filarias

belong to class Secernentea with the parasitic ones causing the filarial diseases such as river blindness casued by Onchocerca volvulus and elphantiasis

Ascaris

genus of parasitic worms belonging to class Chromadorea

Pinworms

also belong to class Secernentea

Hookworms

like Ancylostoma duodenale and Necator americanus cause intestinal infections

Platyhelminths

or flatworms have almost 30,000 known species

schistosomiasis

intestinal flukes causes this or snail fever

Tapeworms

belong to class Cestoda with more than 3,000 known species

Planarians

belong to class Turbellaria with around 4,500 species of largely free-living flatworms

Arthropods

largest phylum of animals in our planet with more than 1.2 million known species

hemocoel

open circulator system where the combined blood and interstitial fluid bathes their organ directly

Chicilerata

subphylum that include spiders, scorpions, and horseshoe crabs

Spiders

belong to class Arachinda and order Araneae with more than 45,000 living species

Scorpions

belong to class Arachnida but under order scorpiones

Horseshoe crab

marine organisms with a horsesoe-shaped carapace

Hemocyanin

blue in color and is harvested for use in detecting bacterial endotoxings.

Myriapoda

the subphylum of arthropods

Millipedes

belong to class Diplopoda with around 12,000 known species

Centipedes

belongo to class Chilopoda with around 8,000 living species

Crustacea

subphylum of mostly aquatic inverebrates with almost 70,000 known species

Krills

belong to order Euphausiancea with almost 90 known species

Shrimps

have plate-like gills and two pairs of legs while prawns have branched gills and three pairs of legs with the second pincers being the largest

Crabs

have a pair of large claws for defense and catching prey and a thicker and harder carapace than shrimps

Lobster

have characteristic long body

Hexapoda

largest subphylum of arthropods

Insecta

largest class of animals

bees

important pollinators belonging to order Hymenoptera

Ants

also social insects belonging to order hymenoptra and Family formicidae

Butterflies

are polymorphic insects belonging to the order Lepidoptera, along with the moths

Cockroaches

are hardy and prolific insects belonging to order Blattodea