Biological Classification and Evolution

The study of the diversification of living things, past and present, and their relationships.

A named group of organisms in a hierarchical classification system.

A system of classification that groups organisms into progressively smaller, more specific categories, such as Domains, Kingdoms, etc.

The evolutionary history of a species or group of related species.

Unique, universally understood names for species, given in Latin.

A sterile layer of cells protects spores and gametes, ensuring their survival and preventing damage.

Tiny openings on the gametophyte allow for the passage of sperm or other substances.

Single-celled root-like structures that anchor the gametophyte and absorb water.

A waxy layer that coats the plant to prevent water loss.

Root-like structures composed of multiple cells, providing greater stability and water absorption.

Specialized cells in vascular tissue responsible for transporting water (hydroids) and nutrients (leptoids).

Tiny pores on plant leaves that regulate gas exchange, allowing for carbon dioxide uptake and oxygen release.

Specialized tissues that transport water and nutrients throughout the plant, enabling growth and development.

A domain of single-celled organisms with unique features like ether lipids in their cell membranes and the ability to thrive in extreme environments.

A domain of single-celled organisms with peptidoglycans in their cell walls, diverse metabolic capabilities, and important roles in ecosystems.

A domain of organisms characterized by having a true nucleus and membrane-bound organelles, often multicellular and complex.

Cells without a true nucleus or membrane-bound organelles, characteristic of bacteria and archaea.

A form of asexual reproduction in prokaryotic cells where a single cell divides into two identical daughter cells.

A process where bacteria take up DNA fragments from their environment, often from dead bacteria.

A process where viruses transfer genetic material from one bacterium to another.

A process where bacteria directly transfer genetic material through a conjugation pilus, a temporary connection between two cells.

Photosynthetic bacteria with chlorophyll a, known for their ability to fix atmospheric nitrogen, contributing to ecosystems.

Organisms that thrive in high temperature environments.

Organisms that thrive in high salt concentration environments.

Organisms that thrive in acidic environments.

Heterotrophic eukaryotic organisms that obtain nutrients by decomposing organic matter, characterized by filamentous structures called hyphae that form a network called mycelium.

A unique stage in the fungal life cycle where two haploid nuclei coexist in a single cell before fusing.

Reproductive structures that can develop into new organisms without fertilization.

The diploid generation of a plant's life cycle that produces spores.

The haploid generation of a plant's life cycle that produces gametes (sperm and egg).

A structure within a plant that produces megaspores (female reproductive cells).

The female gametophyte stage of a plant, which develops from a megaspore.

Seeds that are not enclosed within a fruit, typical of gymnosperms.

A structure in plants that contains the male gametophyte, responsible for carrying sperm.

A layer of tissue in woody plants responsible for producing new wood and bark cells.

Monoecious plants have both male and female reproductive organs on the same individual, while dioecious plants have them on separate individuals.

A specialized structure in gymnosperms that produces either pollen or seeds.

The structure within a plant that develops into a seed after fertilization.

The protective outer layer of a seed.

The reproductive structure of angiosperms, responsible for attracting pollinators and producing seeds.

The part of a flower that encloses the ovules and develops into a fruit after fertilization.

A process unique to angiosperms, involving one sperm nucleus fusing with the egg cell to form a zygote, and the other sperm nucleus fusing with the central cell to form the endosperm.

Provides nourishment for the developing embryo inside a seed.

The initial event that marked the beginning of the universe, characterized by extremely high temperature and density.

The process by which gases cool and change into liquids, a crucial step in Earth's formation.

The process by which plants use sunlight, water, and carbon dioxide to produce their own food, releasing oxygen as a byproduct.

A process where one organism lives inside another, forming a mutually beneficial relationship. This is how mitochondria and chloroplasts evolved.

A process that involves the combination of genetic material from two parents to create offspring with more genetic diversity.

The state of being composed of multiple cells, allowing for specialization of functions and greater complexity.

A significant evolutionary event marking the transition of life from aquatic environments to terrestrial ones.

The evolutionary trend towards a dominant sporophyte generation in plants, indicating a shift in the life cycle.

Light from distant galaxies is shifted towards red wavelengths, indicating they are moving away from us, supporting the idea of an expanding universe.

A faint, uniform glow of radiation, detected throughout the universe, is thought to be the leftover heat from the Big Bang.

The early Earth's atmosphere was primarily composed of reducing gases, like hydrogen sulfide, ammonia, methane, and water vapor.

In 1953, Stanley Miller simulated early Earth conditions to demonstrate that organic molecules could form from inorganic components.

The first living cells on Earth were heterotrophic, meaning they obtained energy by consuming organic molecules from their environment.

Photosynthesis, developed by early cyanobacteria, released oxygen into the atmosphere, transforming it from a reducing to an oxidizing environment.

Oxygen in the upper atmosphere reacted with ultraviolet radiation to create the ozone layer, shielding life from harmful UV rays.

Mitochondria and chloroplasts, present in eukaryotic cells, resemble bacteria in structure and function, suggesting they originated from symbiotic relationships.

Mitochondria and chloroplasts divide independently of the cell, through binary fission, characteristic of bacteria.

Mitochondrial and chloroplast DNA possess similarities to bacterial DNA, supporting their bacterial ancestry.

Charophytes, a group of green algae, represent the closest living relative to land plants, adapted to shallow freshwater habitats.

The transition from aquatic to terrestrial life began with thallose plants, lacking roots and stems, resembling liverworts.

Some plants cope with dry conditions by avoiding them, restricting their growth to moist environments.

Vascular plants evolved mechanisms for protecting against water loss, allowing them to thrive in drier habitats.