Plant Evolution Flashcards

Flashcards covering key vocabulary and concepts from the lecture on plant evolution, focusing on chlorophytes, streptophytes, and embryophytes.

Chlorophytes

A group of green algae that are closely related to streptophytes. Can be unicellular or multicellular; multicellularity is achieved through a phycoplast.

Streptophytes

A group of green algae that are ancestors to land plants (embryophytes). Can be unicellular or multicellular; multicellularity is achieved through a phragmoplast leading to plasmodesmata.

AGF (Ancestral Green Flatalence)

The name given to the green plant ancestor of both chlorophytes and streptophytes, believed to be a unicellular organism.

Phycoplast

The structure in multicellular chlorophytes that facilitates cell adhesion, forming a single pore between cells.

Phragmoplast

The structure in multicellular streptophytes that facilitates cell adhesion, leading to the formation of plasmodesmata.

Plasmodesmata

Extensions of the endoplasmic reticulum that go between plant cells, particularly in streptophytes and land plants, facilitating communication and transport.

Cytokinesis

The process of cell division.

Isogamous

Describes gametes that are the same size, often labeled with plus and minus to indicate opposite types.

Gametophyte

The haploid multicellular organism in plants that undergo alternation of generations, producing gametes through mitosis.

Sporophyte

The diploid multicellular organism in plants that undergo alternation of generations, producing spores through meiosis.

Sporangia

Tissues of the sporophyte where meiosis occurs, generating haploid spores.

Gametangia

Tissues of the gametophyte where gametes are produced by mitosis.

Zygotic Life Cycle

A life cycle in which the only diploid cell is the zygote, which immediately undergoes meiosis (e.g., stoneworts).

Gametetic Life Cycle

A life cycle in which the only haploid cell in the life cycle is the gamete.

Anisogamous

Describes gametes that are different sizes (eggs and sperm).

Archegonia

The female gametangia in embryophytes that produce and retain the egg.

Antheridium

The male gametangia in embryophytes that makes and releases sperm.

Embryophytes

Plants that retain the egg inside the gametangia, where the zygote forms and develops into an embryo sporophyte protected by the parent tissues; also known as land plants.

Sporopollenin

A highly resistant chemical found in the cell walls of spores and pollen grains, providing protection against dehydration, chemical damage, and UV degradation.

Tracheophyte

A clade name for the vascular plants.