7 PLANT LIFE W H A T I S A P L A N T Classifying the Plant World There are many organisms on Earth with similar characteristics The plant kingdom has many divisions We call each division a phylum The kingdoms Protista and Fungi also contain organisms with plant like characteristics but they are not considered plants A class is a division of a phylum Further division of the plant kingdom follows the groupings of Carolus Linnaeus used for all organisms Classes of organisms are divided into groups called orders followed by families and finally the genus and species The genus and species is the first and last name of an organism They are Latin names Every known organism on Earth has a scientific name in Latin The Latin name for human is Homo sapiens When we think of plants we often think of plants belonging in the Coniferophyta or the Anthophyta phylums Carolus Linnaeus 1707 1778 Getting to know Carl von Linné was born in Sweden in 1707 We know him by his Latin name Carolus Linnaeus Linnaeus was interested in nature and plants He taught himself about biology and botany the study of plants He devised a system to classify all the plants and animals known at that time He described living things and grouped them by their shared physical characteristics For instance he put animals with backbones or vertebrae in one group and those without a backbone in another He put animals that laid eggs in one group and those that had live young in another Linnaeus gave each group and each kind of living thing a Latin name made up of two descriptive words Scientists refer to this system as the binomial two names system of nomenclature naming In 1735 he published a series of books Systema Naturae which described and named all the animals and plants known at that time Scientists today still use his binomial classification system to organize and understand all living things
N Coniferophyta are cone-bearing plants The cones contain the plants T seeds Some common examples of conifer trees are pines and bald cypress trees We cut down many conifer trees for lumber Angiosperms are seed-bearing vascular plants Their reproductive structures are flowers in which the ovules are enclosed in an ovary Angiosperms are found in almost every A L P PLANT LIFE PLANT LIFE habitat from forests and grasslands to sea margins and deserts Angiosperms display a huge variety of life forms including trees herbs submerged aquatics bulbs and epiphytes The largest plant families are Orchids and Compositae daisies and Legumes beans There are an estimated 352,000 species of flowering plants or angiosperms A S I T A H W Bryophyta Hepatophyta Pteridophyta Lycopophyta The Plant Kingdom Phylum Mosses Liverworts Ferns Club moss Coniferophyta Cone-bearing plants Angiosperms Flowering plants 8
PLANT LIFE PLANT LIFE Protista Algae and Diatoms The Protista Kingdom Marine diatoms as seen through a microscope The Fungi Kingdom Phylum Black molds Green molds blue molds yeasts mildew Zygomycota Ascomycota Basidiomycota Mushrooms puffballs The Parts of Plants Plant Cells All living things are made up of small parts called cells Plant and animal cells are similar Animal and plant cells have a nucleus that contains genetic substances such as DNA Around the nucleus there is jelly-like cytoplasm Both plant and animal cells have special structures in their cytoplasm called organelles Mitochondria use nutrients to release energy for the cells The endoplasmic reticulum is a folded membrane that makes proteins and fat molecules A noticeable difference between plant and animal cells is their shape Plant cells have rigid cell walls around them This causes plant cells to be rectangular and blocky The walls are made of a tough material called cellulose T H E P A R T S O F A P L A N T 9
10 PLANT LIFE T H E P A R T S O F A P L A N TRobert Hooke 1635 1703 Getting to know Robert Hooke was born in England in 1635 He went to Oxford University in 1653 He later became the chief scientist for the famous Royal Society of London a gathering of the foremost scientists of that time The society had a meeting every week Hooke performed three or four new experiments at each meeting Hooke was curious about living things He used an instrument called a microscope to look at objects up close Hooke looked at insects plants hair and fossils He became the first person to see cells when he looked at a piece of bark under his microscope Hooke made drawings of what he saw In 1665 he published his studies in a book called Micrographia An illustration from Hooke’s Micrographia Magnified plant cells have a blocky appearance chloroplast KLOR-uh-plast a plant cell structure that contains the green pigment chlorophyll mitochondria mitt-oh-KAHN-dree uh a cell structure that takes energy from nutrients and makes it available for other cell processes phloem FLOW-uhm tubular cells in plants that carry food from leaves to roots xylem ZIE-luhm tubular cells in plants that carry water and nutrients from roots to leaves
