BIOL 1123: Principles of Biology II - Exam 2 Study Guide

These flashcards cover major concepts, terminology, and processes related to plant structure, function, evolution, reproduction, and animal diversity.

Plant Organization

The hierarchical structure of plants: cells → tissues → organs → organ systems.

Shoot System

The part of a plant above ground that includes stems, leaves, and flowers.

Root System

The part of a plant below ground that anchors the plant and absorbs water and nutrients.

Roots

Anchoring structures that absorb water and nutrients; contain root hairs to increase surface area.

Root Hairs

Tiny extensions of root cells that enhance the absorption of water and nutrients.

Taproot System

A root system consisting of one main root with smaller lateral roots.

Fibrous Root System

A root system where many thin roots spread out from the base of the stem.

Stems

Structures that support the plant, transport nutrients, and position leaves towards sunlight.

Rhizomes

Underground stems that can produce new shoots and roots.

Tubers

Enlarged underground stems that store carbohydrates.

Stolons

Horizontal stems that grow along the soil surface; also known as runners.

Leaves

Photosynthetic organs that consist of blade, petiole, stomata, and guard cells.

Stomata

Small openings on leaves that control gas exchange.

Guard Cells

Cells that surround stomata and regulate their opening and closing.

Pistil

The female reproductive structure of a flower, including stigma, style, and ovary.

Stamen

The male reproductive structure of a flower, including anther and filament.

Plant Tissue Systems

Dermal, vascular, and ground tissues that serve different functions in plants.

Xylem

Vascular tissue that transports water and minerals from roots to leaves.

Phloem

Vascular tissue that transports sugars produced in leaves to other parts of the plant.

Transpiration Pull

The process by which water moves from roots to leaves through evaporation.

Cohesion

The attraction between water molecules that aids in water transport in plants.

Adhesion

The attraction between water molecules and the walls of xylem vessels.

Root Pressure

Pressure generated in roots that helps push water up through the plant.

Water Potential

The potential energy of water in a system; drives water movement.

Endodermis

The innermost layer of the cortex in roots that regulates water entry.

Casparian Strip

Band of cell wall material in endodermis that blocks passive flow of materials.

Source Tissues

Parts of the plant (usually leaves) that produce or release sugars.

Sink Tissues

Parts of the plant (like roots or fruits) that consume or store sugars.

Meristems

Tissues in plants that are actively dividing and responsible for growth.

Apical Meristems

Meristems located at the tips of roots and shoots; responsible for primary growth.

Lateral Meristems

Meristems that add thickness to stems and roots; responsible for secondary growth.

Annual Plants

Plants that complete their life cycle in one growing season.

Biennial Plants

Plants that complete their life cycle in two growing seasons.

Perennial Plants

Plants that live for more than two years.

Charophyte Algae

The group of green algae that are closest relatives to land plants.

Adaptations to Land

Features such as cuticle, lignin, and seeds that help plants survive on land.

Cuticle

A waxy covering on plant surfaces that reduces water loss.

Lignin

A complex organic polymer that provides structural support in plant cell walls.

Vascular Tissue

Tissue responsible for transport of water, nutrients, and food in plants.

Pollen

The male gametophyte of seed plants; crucial for reproduction.

Seeds

Structures that contain the embryo and provide protection and nourishment.

Alternation of Generations

The life cycle of plants alternating between sporophyte (diploid) and gametophyte (haploid) phases.

Sporophyte

The diploid phase in the plant life cycle that produces spores.

Gametophyte

The haploid phase that produces gametes (sperm and eggs).

Bryophytes

Non-vascular plants like mosses; typically small and require moist environments.

Pterophytes

Seedless vascular plants such as ferns, characterized by the presence of lignin and vascular tissue.

Gymnosperms

Seed-producing plants that bear their seeds on cones.

Angiosperms

Flowering plants that produce seeds enclosed in fruit.

Double Fertilization

A unique process in angiosperms where one sperm fertilizes the egg and the other combines with polar nuclei to form endosperm.

Zygote

The diploid cell formed when a sperm fertilizes an egg.

Endosperm

Nutrient-rich tissue that supports the developing embryo in angiosperms.

Monocots

Plants with one seed leaf; includes grasses and lilies.

Dicots

Plants with two seed leaves; includes roses and oaks.

Fruit Development

The process by which the ovary of a flower transforms into a fruit.

Simple Fruits

A fruit derived from a single ovary.

Multiple Fruits

A fruit that forms from a cluster of flowers.

Aggregate Fruits

A fruit formed from multiple ovaries of a single flower.

Accessory Fruits

Fruits that develop from parts of the flower other than the ovary.

Multicellular Organisms

Organisms composed of many cells; a defining characteristic of animals.

Heterotrophic

Organisms that cannot produce their own food and must consume others for energy.

Eukaryotes

Organisms whose cells contain a nucleus and organelles.

Symmetry

The balanced proportions of the body; can be asymmetrical, radial, or bilateral.

Asymmetry

Lack of symmetry; seen in organisms like sponges.

Radial Symmetry

Symmetry around a central axis; seen in organisms like jellyfish.

Bilateral Symmetry

Dividing the body into two mirror-image halves; related to cephalization.

Cephalization

The concentration of sensory and brain structures in the anterior part of the body.

Germ Layers

Three layers (ectoderm, mesoderm, endoderm) that develop during embryonic development.

Diploblastic Animals

Animals with two germ layers: ectoderm and endoderm.

Triploblastic Animals

Animals with three germ layers: ectoderm, mesoderm, and endoderm.

Acoelomates

Animals that lack a body cavity between the digestive tract and outer body wall.

Pseudocoelomates

Animals with a body cavity that is not completely lined with mesoderm.

Coelomates

Animals with a true coelom, a body cavity completely lined with mesoderm.

Protostomes

Animals whose mouth develops from the blastopore during embryonic development.

Deuterostomes

Animals whose anus develops from the blastopore; includes vertebrates.

Phyla

Major groups of animal classification based on shared characteristics.

Chordates

Animals with a notochord, dorsal hollow nerve cord, pharyngeal slits, and post-anal tail.

Vertebrates

Subphylum of chordates that have a backbone.

Notochord

A flexible rod that provides support in chordate embryos.

Dorsal Hollow Nerve Cord

The central nervous system structure found in chordates.

Pharyngeal Slits

Slits in the pharynx that are present in the embryonic stage of chordates.

Post-Anal Tail

An extension of the body beyond the anus; present in chordates.

Key Evolutionary Transitions

Important adaptations in vertebrates, including jaws and limbs.

Amniotic Eggs

Eggs with a protective shell and membrane, allowing for reproduction on land.

Endothermy

The ability of mammals to regulate their body temperature internally.

Monotremes

Egg-laying mammals, such as the platypus.

Marsupials

Mammals that give birth to underdeveloped young, which often continue to develop in pouches.

Eutherians

Placental mammals that give birth to developed young.