Tree of Life

Bio Test 3

“Land Plants”

Sister to green algae under archaeplastida. Contain Bryophyta, Polypodiopsida, Gymnosperms, and Angiosperms.

Sporophyte/Gametophyte

Sporophytes are diploid and muticelled, produce spores via meiosis. Gametophytes are haploid and single-celled, and produce gametes via mitosis.

Bryophyta (mosses)

Sits by itself, branches off from vascular plants. Anchored by rhizoids, a root precursor. No vascular tissue, and is gametophyte. Homospory.

Homo/heterospory

Homospory is it produces only one kind of spore. Hetero is it produces two.

Vascular plants

Includes polypodiopsida, and the two -sperms. Uses tracheids (cells with secondary cell walls supported by lignin) and vessel elements (cells with big gaps for water movement) to overcome gravity. They also have roots. Are sporophytes.

Polypodiopsida (ferns)

Sits by itself under vascular plants. Likes the shade. Leaves are cald fronds and when coiled, are called fiddleheads. Homospory and produces spores in sori on its leaves.

Seed plants

Heterospory, with seeds and pollen. Includes gymno and angiosperms

Gymnosperm

Sister to angiosperm, under seed plants. Includes conifers. Its cones can either be male (pollen) or female (ovule).

Angiosperm

Sister to gymnosperm, under seed plants. High diversity and dominant plant type for 145 million years. Have flowers and sometimes fruit.

Ctenophora (comb jellies)

Under Metazoa, earliest branch-off. 550-600 mya. Have combs of cilia. Capture food with colloblast cells, and possess mesoglea between inner/outer tissue. Diploblasts. Rotational symmetry. Difuse nerve net.

Porifera (sponges)

Under Metazoa, second branch-off. 550-650 mya. Larva swims, but adults are stationary. No nerve or muscle cells or germ layers. Have spicules (Silica CaCO3) and spongin fibers (Collagen) for exoskeleton support. Choanocytes.

Cnidaria

Sister to bilateria. Under Metazoa. Cnidocyte cells sting, which use Nematocysts like harpoons. Diploblast. its germ layers have mesoglea in the middle justl ike comb jellies. Have two body plans: polyp or medusa. Diffuse nerve net, radial symmetry.

Bilateria

Bilaterial symmetry, complete digestive tract with mouth and anus, cephalization, central nervous system called ganglia. Triploblast.

Mollusca

Under protostomes for bilateria. Have foot for movement, visceral mass full of organs and gill, and mantle to protect the mass. Sister to annelida.

Annelida

Sister to mollusca. Under protostomes for bilateria. Worms that have metamerism: similar body segments that each have same structure.

Nematoda

Under protostomes. Sister to arthropoda. Roundworms that molt their cuticle of chitin and collagen during growth.

Arthropoda

Under protostomes. Sister to nematoda. Also molt their chitin cuticle during growth, but also their exoskeleton. Their bodies are segmented into tagmata. Have jointed appendages. Insects have spiracles to breathe while crustaceans have gills.

Hexapoda

Under Arthropoda. Usually three body sections and six legs. Have metamorphosis.

Echinodermata

Larva have bilaterial symmetry, adults have pentaradial symmetry. Have endoskeletons with mouths on the bottom. Water vascular system with tube feet. Sister to chordata. Under Deuterostomes.

Chordata

Under deuterostomes and sister to echinodermata. Have pharyngeal gills that aquatic chordates eat with, but are only on vertebrate embryos. Have post-anal tails. Have dorsal hollow nerve chord. Have notochord.