Introduction to Plant Biology and Physiology

These flashcards cover the characteristics of plants, evolutionary groups (nonvascular, vascular seedless, gymnosperms, and angiosperms), plant anatomy, and the physiological processes of transport and growth.

Autotrophs

Organisms that produce their own food, typically through the process of photosynthesis.

Phylogenetic tree

A diagram used in evolutionary biology to illustrate how different groups of organisms share a common ancestor and split into different branches over time.

Nonvascular plants

A group of plants, including mosses, hornworts, and liverworts, that lack vascular tissue and true roots, usually remaining very short.

Vascular tissue

Specialized tissue, including xylem and phloem, that allows plants to grow tall against gravity by transporting water and nutrients.

Angiosperms

The most abundant group of plants on Earth, characterized by the production of flowers and seeds enclosed within fruits.

Gymnosperms

A group of vascular plants with "naked seeds" that are not enclosed in fruits, often found in cones (e.g., conifers).

Spores

Microscopic, unicellular reproductive structures used by nonvascular and vascular seedless plants that lack a food supply for the embryo.

Rhizoids

Structures in nonvascular plants that function like roots by anchoring the plant but do not have the specific anatomical look of true roots.

Xylem

Vascular tissue composed of wide diameter cells that transports water and minerals from the roots upward to the leaves.

Phloem

Vascular tissue that transports sugar-rich sap throughout the plant in any direction ($up, down, left, right$).

Taproot

A large, central root system, such as that found in carrots, often used by the plant for food storage.

Fibrous root system

A diffuse root system typical of grasses where there is no main taproot, but rather many small roots growing out.

Root hairs

Tiny extensions on roots that increase the surface area to volume ratio, thereby increasing the rate of osmosis and diffusion.

Mycorrhizae

A symbiotic relationship between plant roots and fungi where fungal hyphae increase the surface area of roots to help the plant absorb more water and minerals.

Monocot

A classification of flowering plants, such as grasses, characterized by having one cotyledon in the seed and parallel leaf veins.

Eudicot

A classification of flowering plants characterized by having two cotyledons in the seed and vascular bundles arranged in a ring.

Endosperm

A nutrient-rich tissue inside the seeds of angiosperms that provides carbohydrates, proteins, and fats to the developing embryo.

Zygote

The single-celled stage formed when a sperm cell fertilizes an egg cell in plants, animals, or fungi.

Double fertilization

A process unique to angiosperms where one sperm fertilizes the egg to form a zygote and another sperm leads to the formation of the endosperm.

Stomata

Microscopic pores on the surface of leaves that regulate gas exchange, allowing $\text{CO}_2$ to enter and $\text{O}_2$ and water vapor to exit.

Transpiration

The evaporation of water from the stomata of leaves, which creates a drawing force to pull water up from the roots.

Cohesion

The physical property of water molecules being attracted to one another via hydrogen bonds, allowing water to move up a plant against gravity.

Meristems

Regions of stem cells (apical, axillary, or lateral) where new plant cells are produced, allowing for indeterminate growth.

Primary growth

Plant growth that occurs at the tips of the roots and shoots, resulting in an increase in the plant's length.

Secondary growth

Growth that results in the thickening of the plant stem or trunk, producing secondary xylem (wood) and phloem (bark).