BIO 19.3 COMPLEX MULTICELLULARITY

Complex Multicellularity

COMPLEX MULTICELLULARITY

Kingdom Plantae:

•Plants are complex multicellular autotrophs; they have specialized cells and tissues.

•Most plants have several different types of cells that are organized into many specialized tissues.

•For example, vascular tissue is made up of specialized cells that play a role in transporting water and dissolved nutrients.

•Plant cells are different than other cell types in that their cell walls are composed of cellulose, a complex carbohydrate.

COMPLEX MULTICELLULARITY

Kingdom Plantae

•Unlike many other organisms, plants can not move from place to place.

•A few groups have motile sperm but most plants are rooted in the ground.

•Portable reproductive systems, like seeds and spores, enable the dispersal of plants.

COMPLEX MULTICELLULARITY

•As autotrophs, plants are the primary producers in most terrestrial food webs.

•Thus, they provide the nutritional foundation for most terrestrial ecosystems. All food chains eventually lead to a producer, some form of plant which makes sugars from photosynthesis using water and carbon dioxide as raw materials.

•Plants also release oxygen to the atmosphere.

•Plants are also very important in the cycling of carbon, phosphorous, water and nitrogen through the biosphere and it’s many biomes.

COMPLEX MULTICELLULARITY

Kingdom Plantae

•Like fungi, plants evolved on land and are the dominant organism on the Earth’s surface.

•Plants cover every part of the world’s terrestrial landscape except for the extreme polar regions and the highest mountain areas.

•Plants are also the major source for food for humans and other animals. They are additionally sources of medicine, fabric dyes, materials for construction of everything from our furniture to our homes.

KINDS OF PLANTS:

•Kinds of Plants:

•There are four basic kinds of plants:

•Nonvascular plants•Seedless vascular plants•Nonflowering seed plants•Flowering seed plants

NONVASCULAR PLANTS

Nonvascular Plants:

•Plants without a well developed system of vascular tissues are called nonvascular plants. These plants are all relatively small.

•They lack the tissue to transport water and dissolved nutrients.

•They also lack true roots, stems and leaves.

•Mosses are the most familiar example of nonvascular plants.

VASCULAR PLANTS

Vascular Plants

•Plants with a well developed system of vascular tissues are called vascular plants.

•Their larger, more complex bodies are organized into roots, stems and leaves.

•Most plants are vascular plants.

•One group of vascular plants, called seedless vascular plants, does not produce seeds.

TYPES OF PLANTS: SEEDLESS VASCULAR

•Seedless vascular plants

•Ferns are the most familiar of seedless vascular plants. They have roots, stems and leaves their surface is coated with a waxy covering that reduces water loss.

•They reproduce with spores that are resistant to drying out. Both haploid and diploid phases occupy significant parts of their life cycle.

VASCULAR PLANT TYPES•Most vascular plants that produce seeds are called seed plants.

•There are two general types of seed plants:•Nonflowering seed plants: Gymnosperms are vascular plants that reproduce using seeds but do not produce flowers. Gymnopsperms include plants that produce seeds in cones, such as pine trees. Seeds enable plants to scatter offspring and to survive long periods in harsh environments.

•Flowering seed plants: Most plants that produce seeds also produce flowers. Flowering plants are called angiosperms. Angiosperms, such as roses, grasses, and oaks, produce seeds in fruit. Fruits are structures that enable the dispersal of seeds.

KINGDOM ANIMALIA

Kingdom Animalia:

•Animals are complex multicellular heterotrophs. Their cells are mostly diploid, lack a cell wall, and are organized into tissues.

•In addition, their zygotes develop through several stages. These adaptations have enabled animals to be successful in different habitats.

•The specialized tissue called muscle enables animals to move about easily. Movement enables animals to avoid predators and to search for food and mates.

KINGDOM ANIMALIA

Kingdom Animalia:•Most animals reproduce sexually.

•In animals, cells formed in meiosis function directly as gamates.

•The haploid cells do not divide by mitosis first, as they do in plants and fungi, but rather fuse directly with one another to form a zygote.

•The zygote than eventually develops into an adult, going through several developmental stages.

KINGDOM ANIMALIA

Kingdom Animalia

•Almost all animals are invertebrates; that is, they lack a backbone.

•Of the more than one million living species, only about 42,500 have a backbone. These organisms with a backbone are called vertebrates.

•The animal kingdom includes about 35 phyla, most of which live in the sea.

•Far fewer phyla live in fresh water, and fewer still live on land.

KINDS OF ANIMALS

Kinds of Animals:

•Animals are very diverse in form. They can range in size from microscopic mites that live on your skin to giant squids hundreds of feet long that are invertebrates.

•Blue whales can reach a length of 100 feet and weigh up to 220 tons.

•The many types of animals that exist are grouped by phylum.

•The following ten categories cover the many phylum of animals that exist on our biosphere: sponges, cnidarians, flatworms, roundworms, segmented worms, mollusks, arthropods, echinoderms, invertebrate chordates, and vertebrates.

KINGDOM ANIMALIA

Sponges:

•Sponges are the only animals that do not have tissues, but they do have specialized cells.

KINGDOM ANIMALIA

Cnidarians:

•Cnidarians are mostly marine animals; they include jellyfish, sea anemones, and corals.

KINGDOM ANIMALIA

Flatworms

•Flatworms have flat, ribbon-like bodies.

•Some are parasitic and live inside the bodies of other animals.

•Others are free-living and may live in soil or water.

KINGDOM ANIMALIA

Roundworms

•Nematodes, or roundworms, are small worms that have long slender bodies.

•Some roundworms are free-living in soil or water while others are parasites of animals or plants.

KINGDOM ANIMALIA

Segmented worms

•Annelids, or segmented worms, live in both soil or water and include the familiar earthworm.

•Bristled marine worms are segmented worms, as are leeches, which can be blood-sucking parasites.

KINGDOM ANIMALIA

Mollusks

•Mollusks have long sac-like cavities called a coelom that encloses internal organs.

•Mollusks are very diverse aquatic and terrestrial animals. They include snails, oysters, clams, octopuses, and squids.

•Most mollusks have a hard external skeleton called a shell.

KINGDOM ANIMALIA

Arthropods:

By far the most diverse group of animals, arthropods have an external skeleton.

They also have jointed appendages, such as antennas and jaws. These structures enable arthropods to sense their environment and obtain food.

Two thirds of all named species are arthropods, most of them in the insect category.

The high rate of reproduction by insects has contributed to their success.

KINGDOM ANIMALIA

Echinoderms

•This group of invertebrates includes sea stars, sea urchins, and sand dollars.

•Many echinoderms are able to regenerate a lost limb.

•In fact, some echinoderms can lose a limb to a predator in order to escape that predator.

COMPLEX MULTICELLULARITY

•Invertebrate Chordates

•Invertebrate chordates are aquatic animals that have much in common with vertebrates, though they do not have a backbone.

•Some invertebrate chordate are swimmers that resemble fish, while others live attached to a rock or other object.

COMPLEX MULTICELLULARITY

Vertebrates

•Vertebrates have an internal skeleton made of bone, a backbone vertebral column that surrounds and protects the spinal column and a head with a brain contained in a bony skull.

•Vertebrates include mammals, fish, birds, reptiles and amphibians.