Untitled Flashcards Set

Alternation of generations

A life cycle typical of plants in which a diploid sporophyte generation alternates with a haploid gametophyte generation.

Sporophyte

The multicellular diploid stage in the life cycle of a plant that produces haploid asexual spores through mitosis.

Gametophytes

The multicellular haploid stage in the life cycle of plants.

Multicellular Embryos

Distinguishes plants from other photosynthetic organisms.

Chlorophyll

Green pigment which plays a crucial role in photosynthesis.

Diploid

Cells which contain two complete sets (2n) of chromosomes.

Haploid

Cells which contain only one complete set of chromosomes (n).

Gametes

Zoospores; Sperm (male) and eggs (female).

Zygote

Fertilized egg (diploid).

Embryo

Developed from a Zygote which matures into a sporophyte.

Photosynthetic Protists

Ancestors of plants.

Stoneworts

The closest living relatives to plants.

Mitosis

Division of a parent cell, producing 2 identical daughter cells.

Meiosis

2 divisions of a germ cell, producing 4 non-identical gametes.

Cuticle

Covers the surfaces of leaves and stems and limits the evaporation of water.

Stomata

Pores in leaves and stems that open to allow gas exchange.

Lignin

A stiffening substance that supports the plant body.

Nonvascular Plants

Also known as bryophytes which require moist environments to reproduce.

Vascular Plants

Also known as tracheophytes; able to colonize drier habitats.

Rhizoids

Rootlike anchoring structures for nonvascular plants.

Conducting Vessels

Xylem and Phloem; transports minerals and water throughout a vascular plant.

Protective structures for gametes

Archegonium (female egg) and Antheridium (male sperm).

Heteromorphic

Different overall appearance of the gametophyte and sporophyte.

Isomorphic

Similar overall appearance of the gametophyte and sporophyte.

Gymnosperms

Nonflowering plants such as conifers.

Angiosperms

Flowering plants such as monocots and dicots.

Seeds

A replacement for spores as land plants evolved.

Pollen

Evolution of the male gametophyte.

Mycelium

The body of most fungi; an interwoven mass of one-cell-thick thread-like filaments.

Hyphae

Thread-like structure that consists of elongated cells, often with many haploid nuclei.

Septa

A partition that separates the fungal hypha into individual cells.

Chitin

Structural polysaccharide with strength in the fungal cell wall.

Spores

Haploid cells capable of developing into an adult without fertilization.

Chytrids

Oldest known fossil fungi that live in water. Requires it for reproduction.

Zygomycetes

Fungi that live in soil or on decaying material.

Sporangia

Structure in which spores are produced.

Glomeromycetes

Fungi that form symbiotic relationships with plant roots.

Basidiomycetes

Club fungi that form club-shaped reproductive structures.

Basidia

Diploid cells that produce basidiospores by meiosis.

Ascomycetes

Sac fungi that form cup-shaped structures or mushroom-like fruiting bodies.

Ascus

Saclike case in which sexual spores are formed by Ascomycetes.

Morels

Mushroom-like fruiting bodies of certain types of Ascomycetes.

Lichens

Symbiotic association between an algae and a fungus.

Mycorrhizae

Symbiotic relationship between fungi and plant roots.

Endophytes

Fungi that live inside plant stems and leaves.

Saprophytes

Fungi that feed on dead organisms.

Root System

All of the roots of a plant.

Root

Plant part that provides anchorage and absorbs water and nutrients.

Shoot system

All parts of a vascular plant exclusive of the root.

Monocots

Type of flowering plant characterized by embryos with one seed leaf.

Dicots

Type of flowering plant characterized by embryos with two seed leaves.

Cotyledon

Part of a plant embryo that stores food reserves and transfers food to the rest of the embryo.

Meristem cells

Cells that remain capable of division throughout the life of a plant.

Differentiated cells

Mature cells specialized for a specific function.

Apical meristems

Clusters of meristem cells at the tip of shoots or roots.

Primary growth

Growth produced by apical meristem, lengthening roots and shoots.

Lateral Meristems

Meristem tissue that forms cylinders parallel to the long axis of roots and stems.

Secondary growth

Growth in diameter and strength of a stem or root due to lateral meristem division.

Tissue

A group of cells that together carry out a specific function.

Tissue system

A group of two or more tissues performing a specific function.

Dermal Tissue System

Covers the outer surface of the plant body.

Ground Tissue system

Bulk of young plants, involved in photosynthesis and support.

Vascular Tissue System

Transports fluids throughout the plant body.

Epidermal tissue

Forms the epidermis which secretes cuticles.

Epidermis

Outermost cell layer that covers leaves, stems, and roots.

Periderm

Cell layers that help anchor the plant in the soil.

Parenchyma

Most abundant ground tissue that carries out metabolic activities.

Collenchyma

Provides support for young and non-woody plants.

Sclerenchyma

Cells with thick hardened walls; provide strength.

Xylem

Transports water and minerals from roots to shoots.

Tracheids

Thin elongated cells in xylem.

Pits

Porous dimples in cell walls that separate adjacent cells.

Vessel elements

Cells in xylem that are elongated and dead at maturity.

Vessels

Tubular structures in xylem composed of vessel elements.

Phloem

Transports organic molecules, including sugars and hormones.

Sieve-tube elements

Cells that form sieve tubes in phloem.

Sieve plates

Structures between sieve tube elements allowing cytoplasm connection.

Companion cells

Cells adjacent to sieve-tube elements involved in their nutrition.

Plasmodesmata

Connect companion cells to sieve-tube elements.

Leaves

Major photosynthetic structures of most plants.

Blade

The flat part of a leaf.

Petiole

The stalk that connects the blade of a leaf to the stem.

Guard cells

Cells that enclose and adjust the size of stomata.

Mesophyll

Middle of the leaf containing chloroplasts and conducting photosynthesis.

Vascular bundles

Veins in leaves that contain xylem and phloem.

Stems

Aboveground portion of a plant body that bears leaves and reproductive structures.

Terminal bud

Meristem tissue located at the tip of a plant shoot.

Leaf primordial

Cluster of cells developing into a leaf.

Node

Region of a stem where the petiole of a leaf is attached.

Internodes

Parts of the stem between two nodes.

Lateral Buds

Clusters of meristem cells found at nodes of stems.

Flower buds

Clusters of cells that form a flower.

Cortex

Part of a primary root or stem located between the epidermis and vascular cylinder.

Pith

Cells forming the center of a root or stem.

Major Functions of the cortex and pith

Support, storage, and photosynthesis.

Vascular Cambium

Lateral meristem that gives rise to secondary xylem and phloem.

Sapwood

Young secondary xylem that transports water in a tree trunk.

Heartwood

Older secondary xylem that no longer conducts water.

Palisade cells

Mesophyll cells toward the topside of the leaf.

Spongy cells

Cells on the bottom side of the mesophyll with air spaces.