PLANTS & ANIMALS

Plants•Modern land plants are descendants of green algae.  Three obstacles that land plants had to overcome are

•1) conservation of water, •2) reproduction on land & •3) how to absorb minerals from the surface. 

•The 2 groups of modern plants include 1) vascular - these use special tissues that transport water & nutrients throughout the plant &

•2) nonvascular- these have no tissue & transport nutrients through osmosis & diffusion.

Groups of Plants

• I. Nonvascular Plants (mosses)• II. Vascular Plants

A. Seedless Vascular Plants (ferns)

B. Vascular Plants with Seeds

1. Gymnosperms (pines, cycads)

2. Angiosperms (maples, roses)

NONVASCULAR PLANTS

•Bryophytes – These have no true roots, stems, or leaves.  The life cycle of bryophytes exhibits an alternation of generations in which the haploid gametophyte is the dominant form.  Bryophytes are divided into 3 classes:  mosses, liverworts, & hornworts. 

Moss capsule

liverwort

hornwort

Moss gametophyte

Moss sporophyte

•The diploid (2n) phase of the moss life cycle occurs when gametes fuse.  The zygote develops into a sporophyte, which in turn produces haploid spores by meiosis. 

http://www.sumanasinc.com/webcontent/animations/content/moss.html

•The gametophytes of liverworts & hornworts are haploid.  Both of these groups have a life cycle similar to that of mosses.  Liverworts also reproduce asexually by spores & by the production of gemmae usually formed in special gemmae cups.

•Bryophytes have rhizoids that are tiny root-like structures & cuticles that helps prevent dessication.  They need water to reproduce.

VASCULAR PLANTS

•The vascular plants developed specialized vascular tissues as well as roots, stems, & leaves.  These structures enabled vascular plants to grow taller, disperse their reproductive cells more widely, & withstand harsher conditions than nonvascular plants.

•Seedless vascular plants require water for sexual reproduction.  Whisk ferns, horsetails, club mosses, & ferns are living relatives of the early seedless vascular plants.  Ferns, the most varied seedless vascular plants, also commonly reproduce using spores formed in sori.

Whisk fern

Club Moss

Resurrection plant

Fern with sori

fiddleheadhttp://www.harcourtschool.com/activity/science_up_close/416/deploy/interface.html

• Seed plants include gymnosperms & angiosperms the flowering plants.  Both produce seeds that consist of an embryo plant, a cotyledon (food source) & seed coat.  Gymnosperms were the 1st land plants with seeds.  Their ovules develop naked.  The male gametophyte is called a pollen grain.  Trees produce 2 types of cones:  seed cones (female) & pollen cones (male). 

• Examples of gymnosperms include conifers, cycads, Ginkgo, sequoias.  Conifers have adapted well to life in cold, arid regions.  They do not require water for reproduction.

•Angiosperms are the dominant plants on Earth.  They are classified as monocots or dicots.  Monocots contain one cotyledon, parallel veins, flowers in multiples of 3, & scattered bundles.  They include grass, wheat, corn, palms, bananas. 

•Dicots have 2 cotyledons, netlike veins, flowers in 4’s or 5’s & bundles in circles.  They include maples, roses, oaks, tomatoes.  Angiosperms produce seeds & fruits that provide much of the food essential for animal life.  They enclose their seeds in fruits that help ensure their survival.

PLANT TISSUE • Plants contain 3 kinds of tissue:  epidermal (outer layer), vascular (tube-like), & ground (cushions & protects). All new plant cells are produced in specific areas called meristems.  Cells produced in the root’s apical meristem differentiate into the epidermis, cortex, & vascular cylinder.  Roots may develop as taproots or fibrous roots.  All roots anchor the plant, absorb water & minerals, & store food.

• Stems support plant growth above the ground & transport water & food between the leaves & roots.  The vascular tissue found here includes xylem which takes nutrients from the roots to the leaves & phloem which takes nutrients from the leaves to the roots.  Herbaceous stems are supported by turgor pressure. Woody stems are supported by the wood produced by secondary growth.

• Most of a plant’s photosynthetic cells are contained in the leaves.  Leaves exchange gases & release water by the opening & closing of their stomata which are tiny pores.  Water movement in plants results from root pressure, capillary action & the pull created by transpiration.

• Capillary action pulls water up into the xylem.  The evaporation of water from the leaves (transpiration ) causes the pulling of the water.  90% of the water is lost as vapor through transpiration.  Translocation occurs when carbohydrates are moved from the leaves to the roots.

REPRODUCTION IN FLOWERING PLANTS

• Flowers consist of highly modified leaves that are specialized to carry out sexual reproduction.  Essential flower parts include the pollen-producing anther & the pistil that contains the ovary.  The nonessential flower parts protect & adorn the reproductive structures & aid in pollination.  They are called calyx (sepals) & corolla (petals). 

• A perfect complete flower has all the essential & nonessential flower parts – ex. roses, lily, tomatoes.  An incomplete flower lacks 1 or more parts – ex. grass, corn, squash.  An imperfect flower has the reproductive structures of only 1 sex – ex. holly, persimmon, squash.

•Pollination is the process of transferring ripe pollen from the anther to the stigma.  Each pollen grain contains a tube nucleus & a generative nucleus.  The generative cell produces 2 sperm cells. 

• In double fertilization, one sperm fuses with the egg cell while the other fuses with the polar body.  This forms a embryo & endosperm which nourishes the developing embryo.  In self-pollination pollen stays on 1 flower.  In cross-pollination the pollen is transferred to another plant of the same species.

• A fruit develops from the ovary of a flower.  Fleshy fruits are attractive to animals, which eat them & then disperse their seeds.  Dry fruits have structures that help carry their seeds in air & wind currents.

• Simple fruits have a single ovary – ex. apple, plum, grapes.  Aggregate fruits contain many pistils on the same flower – ex. strawberry, blackberry.  Multiple fruits have many single fruits that fuse together to form 1 single structure – ex. pineapple, corn, fig. 

•Seeds are dispersed by wind, water, animals, & explosion.  Seeds usually experience a dormant period before germination.

• Plants produced asexually have the same DNA as the parent plant.  Plant cultivators use methods of artificial propagation such as cutting & grafting. 

•Invertebrates- No backbone

Porifera – sponges

• Assymmetrical (no symmetry)• Sessile (attached) as adults• Reproduce by fragmentation• Filter feeders

Cnidaria – jellyfish, sea anemones, corals, portuguese man-o-war

• jelly-like • no specialized organs• stinging cells (cnidocytes)• Most are found in marine water• Radial symmetry

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Platyhelminthes – flatworms* soft, thin, flatbodies• Belong to the phylum platyhelminthes. (Plat = flat)• They are acoelomates (they don’t have body cavities)• They have bilateral symmetry• Show cephalization• Respiration through skin• Single opening to digestive tract (pharynx)

Nematoda –round worms* Most are parasiticBelong to phylum Nematoda Pseudocoelomates (fluid filled body cavity)Slender bodies that taper on both endsHave mouth and anusCan be free-living or parasitic

Annelida

Includes duster worms, earthworms, & leeches Abundant in all habitats Have a true coelom fully lined with mesoderm Body divided into external segments called metameres (metamerism)

Arthropoda – segmented bodies, exoskeleton (chitin), jointed appendages

Arthropods• Insects – beetles, butterfly, ants, etc.

*3 body segments, some have wings

Arthropods• Crustacean – crab, crayfish, lobster etc.

*2 body segments – live mainly in water

Arthropods• Arachnid- scorpion, spiders, etc.

*2 body segments, 8 legs, no antennae

Arthropods• Myriapod – centipede, millipede

*long flat bodies, many legs

Mollusca* soft-bodied, usually have a shell, unsegmented

Echinoderms – starfish, sea urchin, sand dollar* marine animals, plates with spines, radial symmetry

Nonvertebrate Chordates

Chordates

•Vertebrates- backbone

Fishes – salmon, tuna, sharks, rays, etc. *aquatic, most are marine

Amphibians – frogs, caecilians, salamanders*Wide variety of habitat, typically start out as larva living in water

Reptiles- snakes, turtles, iguana*dry, scaly skin protects against dehydration

Birds – toucan, penguin, eagle, hummingbird*Have feathers and wings, not all can fly

Mammals – platypus, kangaroos, humans, rodents* mammary glands, hair, live birth (except monotremes)

Habitat of Animals• All biomes

Groups of Animals• Invertebrates (without backbones)• Vertebrates (with backbones)

Cell Type• All animals are eukaryotes.• No animal cells have cell walls.

Uni- or multicellular?• All animals are multicellular.

Nutrition in Animals• All animals are heterotrophic. • They can be filter feeders, predators, parasites,

herbivores, carnivores, omnivores, scavengers, or detritivores.

Transforming Matter & Energy• Animals use cell respiration (either anaerobic fermentation

or aerobic respiration) to transform food particles into useful forms of energy.

Transporting Matter & Energy• Simple animals use diffusion • More advanced organisms have circulatory systems.• Animals may have open or closed circulatory systems.

Eliminating Matter & Energy• Simple animals use diffusion to remove wastes from their

bodies.• More advanced animals use excretory systems to remove

wastes (nephridia or kidneys).

Reproduction in Animals• Some invertebrates reproduce asexually through fission

(stony corals), budding (hydra), fragmentation (planarians) or regeneration (sponges). Others reproduce sexually through sperm & eggs.

Reproduction in Animals• Vertebrates reproduce sexually through sperm & eggs &

may be either internal or external fertilization.