Science 9 - Unit 1

Biological Diversity

The number and variety of organisms in an area, characterized by differences in traits.

Biological Species Concept

A definition of species as a group of organisms that can mate and produce viable offspring.

Reproductive Isolation

Mechanisms that prevent members of different species from interbreeding.

Asexual Reproduction

A mode of reproduction where organisms do not mate, exemplified by bacteria.

Phylogenetic Species Concept

Classification of organisms based on their evolutionary history.

Morphological Species Concept

Classification based on similar physical characteristics among organisms.

Niche

The role or function of an organism within its environment, with narrow and broad niches indicating specialization.

Speciation

The process by which new species are created.

Structural Adaptation

Inherited physical characteristics that enhance survival.

Behavioral Adaptation

Inherited behaviors that improve an organism's chances of survival.

Diversity Index

A measure of biological diversity in a given area.

Generalist

An organism with broad requirements and adaptations for survival in various conditions.

Galapagos Finches

A group of small birds with 13 species found on the Galapagos Islands.

Taxonomy

The science of classifying organisms into categories.

Binomial Nomenclature

A system for naming species using the genus and species names, developed by Carl Linnaeus.

Classification Categories

The eight levels of biological classification:domain, kingdom, phylum, class, order, family, genus, and species.

Prokaryotes

Organisms without a membrane-bound nucleus, possessing DNA.

Eukaryotes

Organisms with membrane-bound nuclei and DNA.

Dichotomous Keys

Tools used to identify organisms through a series of branching choices.

Symbiotic Relationships

Interactions between species, including mutualism, parasitism, and commensalism.

Binary Fission

A form of asexual reproduction where a cell divides into two identical cells.

Budding

A form of asexual reproduction where an offspring grows off the parent organism.

Conjugation

The transfer of genetic material between two bacteria of the same species.

Gamete

Reproductive cells that contain half the number of chromosomes.

Spores

Reproductive units in non-seed plants, often found in mushrooms.

Pollen Tubes

Structures that transport male gametes to fertilize ovules in plants.

Cotyledon

The seed leaf that nourishes the plant embryo.

Embryo

An early developmental stage of a multicellular organism.

Self-Pollination

The process where pollen fertilizes ovules within the same flower.

Zoospore

A swimming spore that uses flagella for movement.

Zygospore

A single-celled reproductive structure formed during sexual reproduction.

Pistil

The female reproductive part of a flower that produces seeds.

Vegetative Growth

A method of asexual reproduction where an offspring develops roots and can be planted.

DNA

A molecule that stores genetic information.

Genes

Sections of DNA that code for specific traits.

Interphase

The phase of the cell cycle where the cell grows and DNA is replicated.

Traits

Specific characteristics of an organism.

Genetic Engineering

The artificial manipulation of genes.

Chromosomes

Long strands of DNA located in the nucleus of eukaryotic cells.

Dominant Trait

An inherited trait that is expressed if present.

Recessive Trait

An inherited trait that is expressed only when both alleles are recessive.

Meristem

A region of undifferentiated cells capable of division.

Mutation

A change in the genetic information of an organism.

Meiosis

A type of cell division that produces gametes with half the chromosome number of the parent cell.

Mitosis

A type of cell division resulting in two identical daughter cells.

Continuous Variation

A genetic trait that exhibits a range of possibilities.

Discrete Variation

An inherited trait with a limited number of variations.

Heritable

A characteristic that can be passed from parent to offspring.

Artificial Selection

The process by which humans select organisms for reproduction.

Natural Selection

The process by which organisms adapt to their environment over time.

Biotechnology

The use of living organisms to create products.

Transgenic

An organism that contains DNA from another species.

Cloning

The process of creating a genetically identical organism.

Species at Risk

Categories of species facing threats to their survival.

Habitat Loss

The destruction of natural environments due to human activities.

Invasive Species

Non-native species that thrive in new environments and disrupt local ecosystems