8th Grade Science Vocabulary

Abiotic

Abiotic

Substance not derived from a living thing. Ex: plastic

Acquired Trait

Developed during your life, such as reading, riding a bike

Allele

One of a number of alternative forms of the same gene

Amino Acids

Molecules that combine to form proteins

Analogous Structures

Features of different organisms with similar function but different structure

Asexual Reproduction

Reproduction where a single parent produces an exact replica

Asthenosphere

Upper layer of the earth's mantle, below the lithosphere

Atmosphere

The envelope of gases surrounding the earth

Autosomal

Trait evenly distributed between females and males on a pedigree chart

Autotroph

Organism that produces its own food

Biodiversity

Number of different species of plants and animals in an area

Biome

Large, naturally occurring community of flora and fauna

Biotic

Organisms that are, or once were, living

Carbon Cycle

Continuous movement of carbon in abiotic and biotic environments

Cellular Respiration

Obtaining energy from breaking chemical bonds in nutrients

Chromatin

Lives in the nucleus; houses DNA containing genes

Commensalism

Relationship where one species benefits while the other is unaffected

Convection

Movement of fluid due to heat energy

Convergent Boundary

Area on Earth where two or more lithospheric plates collide

Crust

Outermost layer of the earth; rigid and rocky

Diploid

Symbolized as 2n; has 23 pairs of chromosomes

Divergent Boundary

Occurs when two tectonic plates move away from each other

DNA

Deoxyribonucleic acid; contains genetic information

Dominant Allele

Expressed in the phenotype when only one is present

Ovum (Egg)

Female reproductive structure contained in the ovaries

Eukaryote

Organism with genetic material contained in a distinct nucleus

Evolution

Changes in genetic material of a population over time

Extinct

Having no living members of the same species

Fertilization

When sperm penetrates the egg, combining genetic material

Food Web

Network of food chains passing energy and nutrients

Fossil Record

History of life as documented by fossils

Frequency

Number of waves passing a fixed place in a given time

Gametes

Sex cells containing genes for offspring

Gene

Section of DNA strand coding for specific traits

Genetic Engineering

Laboratory process altering DNA of an organism

Genetics

Study of heredity and transmission of characteristics

Genotype

Overall genetic makeup of an individual

Geosphere

Portion of Earth including interior and surface rocks

Germ Cell

Haploid cell containing half the chromosomes

Groundwater

Water beneath Earth's surface in rock and soil

Haploid

Sex cells with half the chromosomes as body cells

Heredity

Passing genetic traits from parent to offspring

Heterotroph

Organism unable to make its own food

Heterozygous

Having two different alleles for the same trait

Homologous Structures

Organs suggesting connections to a common ancestor

Homozygous

Both genes are identical for a particular trait

Human Genome Project

Research project determining human DNA base pairs

Hybrid

Organism with heterozygous alleles for traits

Hydrosphere

All water covering the earth

Infiltration

Process by which water on the ground surface enters the soil

Innate Trait

Characteristic an organism is born with

Inner Core

Innermost layer of the earth; solid metal state

Monera

Kingdom consisting of bacteria

Lithosphere

Cool, rigid outermost layer of Earth

Mantle

Largest layer of Earth; where convection currents occur

Medium

Substance in which a wave travels

Sexual Reproduction

Reproduction in sex cells resulting in daughter cells with half the parent chromosomes

Gregor Mendel

Austrian monk known as the 'Father of modern genetics'

Multicellular Organism

An organism composed of many cells, such as animals, plants, and fungi

Mutation

A change in a gene leading to a new inheritable trait

Mutualism

A relationship between animals where both species benefit

Natural Disaster

A phenomenon with potential negative effects on humans and animals

Natural Selection

Process where better-adapted organisms tend to survive and reproduce

Hierarchy of Biological Organization (NCDGP)

Nucleus, Chromosome, DNA, Gene, Protein - largest to smallest

Nucleic Acid

Organic molecules with a nitrogenous base, sugar, and phosphate

outer core

Fluid layer containing liquid iron and nickel

Parasitism

Relationship where one species benefits while harming the other

Phenotype

Observable appearance of a trait or individual

Photosynthesis

Conversion of light energy to chemical energy in plants

Probability

Extent to which something is likely to happen

Prokaryote

Microscopic single-celled organism lacking a distinct nucleus

Protein

Chemical building blocks made of amino acids in cells

Inheritance

Production of offspring with genetic information from two parents

Somatic Cell

Any cell in an organism except reproductive cells

Speciation

Formation of a new species through natural selection

Testes

Male reproductive structure containing sperm

Subduction Zone

Collision of tectonic plates where one plate sinks into the mantle

Succession

Gradual change and development of ecosystems over time

Watershed

Area where all surface water converges to a single point

Variant

Different or distinct form or version of something

Identical

Exactly alike in every detail

Anatomy

Relating to bodily structure and body parts

Continental Crust

Older, thicker, and less dense part of Earth's crust forming landmasses

Density

Measure of how heavy something is compared to its size

Neutral Mutation

DNA sequence changes neither beneficial nor harmful

Beneficial Mutation

DNA sequence changes leading to advantageous traits

Harmful Mutation

DNA sequence changes causing detrimental effects

P Waves

Mechanical waves from earthquakes causing less damage

S Waves

Transverse waves from earthquakes causing more damage

Ultraviolet Radiation

High-energy electromagnetic radiation present in sunlight

X-Rays

High-energy electromagnetic waves passing through materials

Infrared Radiation

Electromagnetic waves emitted by heated objects

Microwaves

Electromagnetic waves used in radars, communication, and heating

Visible Light

Segment of the electromagnetic spectrum visible to the human eye

Radio Waves

Electromagnetic waves used for long-distance communication

Mitosis

reproduction of non-sex cells where the daughter cells produced have the same number of chromosomes as the parent cells

Non renewable resources

sources that run out or will not be replenished in our lifetimes.

Nucleus

found inside a cell, houses chromosomes

Phenotype

The observable appearance of a trait or the overall appearance of an individual.

Photosynthesis

converting light energy to the chemical energy of food in plants