Honors Biology All Vocab

Biogeochemical cycle

process in which elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another

Climate change

Measurable long-term changes in averages of temperature, clouds, winds, precipitation, and the frequency of extreme weather events such as floods, major storms, and heat waves

Symbiosis

A close relationship between two species that benefits at least one of the species.

Point source

A specific source of pollution that can be identified (ex single factory)

nonpoint source

a widely spread source of pollution that is difficult to link to a specific point of origin (ex littering)

carrying capacity

Largest number of individuals of a population that a environment can support

trophic level

Each step in a food chain or food web

ecological pyramid

illustration of the relative amounts of energy or matter contained within each trophic level in a given food chain or food web

Ecological footprint

total amount of functioning ecosystem needed to both provide the resources a human population uses, and to absorb the wastes that population generates

Biodiversity

The total of the variety of organisms in the biosphere

Sustainability

The ability to keep in existence or maintain. A sustainable ecosystem is one that can be maintained

Biomagnification

the increasing concentration of a harmful substance in organisms at higher trophic levels in a food chain or food web

Species

a group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding.

Population

A group of individuals that belong to the same species and live in the same area

Community

All the different populations that live together in an area

Ecosystem

A system formed by the interaction of a community of organisms with their physical environment

biotic

living

Abiotic

Non-living

riparian buffer

trees and forest planted along stream and riverbanks to absorb stuff before it can run into a body of water

watershed

An ecosystem where all water runoff drains into a single body of water

habitat

Place where an organism lives

invasive species

plants and animals that have migrated to places where they are not native that reproduce quickly and harm native species

Bioindicator

a species that is especially sensitive to ecological change and thus can serve as an indicator of environmental conditions

niche

An organism's particular role in an ecosystem, or how it makes its living.

incomplete dominance

Situation in which one allele is not completely dominant over another allele (red+white \= pink)

codominance

A condition in which neither of two alleles of a gene is dominant or recessive. The two are both fully expressed (ex spots, stripes)

Sex linked trait

a trait that is determined by a gene found on one of the sex chromosomes (X)

multiple allele

three or more forms of a gene that code for a single trait (ex IA, IB, i for blood)

polygenic trait

trait influenced by several genes (do not follow mendellian inheritance) ex height, skin color, etc

carrier

A person whose genotype includes a gene that is not expressed in the phenotype.

pedigree

A diagram that shows the occurrence of a genetic trait in several generations of a family.

sex influenced trait

Expressed differently in men than in women, even if it is on an autosome and both sexes have the same genotype

herdity

Passing of traits from parents to offspring

recessive

An allele that is masked when a dominant allele is present

Heterozygous

An organism that has two different alleles for a trait

allele

Different forms of a gene

homozygous

An organism that has two identical alleles for a trait

dominant

Describes a trait that covers over, or dominates, another form of that trait.

gene

A segment of DNA on a chromosome that codes for a specific trait

punnett square

A chart that shows all the possible combinations of alleles that can result from a genetic cross

genetics

The scientific study of heredity

genotype

genetic makeup of an organism

phenotype

An organism's physical appearance, or visible traits.

law of segregation

Mendel's law that states that the pairs of homologous chromosomes separate in meiosis so that only one chromosome from each pair is present in each gamete

law of independent assortment

the law that states that genes separate independently of one another in meiosis

Karyotype

A display of the chromosome pairs of a cell arranged by size and shape.

Gametes

reproductive cells

Crossing-over

Process in which homologous chromosomes exchange portions of their chromatids during meiosis.

Stem cell

unspecialized cell that can give rise to one or more types of specialized cells

Sexual reproduction

A reproductive process that involves two parents that combine their genetic material to produce a new organism, which differs from both parents

Independent assortment

Independent segregation of genes during the formation of gametes

Homologous chromosomes

Chromosomes that have the same sequence of genes and the same structure

Haploid

(genetics) an organism or cell having only one complete set of chromosomes

Nondisjunction

Error in meiosis in which homologous chromosomes fail to separate.

diploid

(genetics) an organism or cell having two sets of chromosomes or twice the haploid number

tetrad

structure containing 4 chromatids that forms during meiosis

ribose

A five-carbon sugar present in RNA

Messenger RNA (mRNA)

RNA molecule that carries copies of instructions for the assembly of amino acids into proteins from DNA to the cytosol

Transfer RNA (tRNA)

An RNA molecule that functions as an interpreter between nucleic acid and protein language by picking up specific amino acids and recognizing the appropriate codons in the mRNA

Ribosomal RNA (rRNA)

type of RNA that makes up the major part of ribosomes

polypeptide

A polymer (chain) of many amino acids linked together by peptide bonds.

transcription

the organic process whereby the DNA sequence in a gene is copied into mRNA (RNA polymerase separates DNA, RNA base pairs added, RNA released when reach termination signal)

RNA polymerase

Enzyme similar to DNA polymerase that binds to DNA and separates the DNA strands during transcription

codon

A specific sequence of three adjacent bases on a strand of DNA or RNA that provides genetic code information for a particular amino acid

anticodon

group of three bases on a tRNA molecule that are complementary to an mRNA codon

translation

(genetics) the process whereby genetic information coded in messenger RNA directs the formation of a specific protein at a ribosome in the cytoplasm

mutation

change in a DNA sequence that affects genetic information

restriction enzymes

Enzyme that cuts DNA at a specific sequence of nucleotides

autosome

Any chromosome that is not a sex chromosome

centromere

Area where the chromatids of a chromosome are attached

asexual reproduction

Process by which a single parent reproduces by itself

sex chromosome

Chromosomes that determine the sex of an individual

chromosome

a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.

binary fission

A form of asexual reproduction in single-celled organisms by which one cell divides into two cells of the same size

chromatin

Clusters of DNA, RNA, and proteins in the nucleus of a cell

chromatid

one of two identical "sister" parts of a duplicated chromosome

cyclin

one of a family of closely related proteins that regulate the cell cycle in eukaryotic cells

nucleic acid

carbon, hydrogen, oxygen, nitrogen, phosphorus; ex DNA, RNA; sugar (deoxyribose or ribose) with nitrogenous base (ex adenine) and phosphate group(s); monomer: nucleotide; used for: genetic information (found in cells); DNA double helix, RNA single helix

nitrogen base

a DNA nucleotide containing nitrogen, a sugar molecule, and a phosphate group

DNA polymerase

Enzyme involved in DNA replication that joins individual nucleotides to produce a DNA molecule

genome

the complete instructions for making an organism, consisting of all the genetic material in that organism's chromosomes

helicase

An enzyme that untwists the double helix of DNA at the replication forks.

Deoxyribose

A five-carbon sugar that is a component of DNA nucleotides

nucleotide

monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base

replication

process of copying DNA prior to cell division

double helix

two strands of nucleotides wound about each other; structure of DNA

restriction enzymes

Enzyme that cuts DNA at a specific sequence of nucleotides

Autotroph

An organism that makes its own food

Heterotroph

An organism that cannot make its own food.

Stomata

Small openings on the underside of a leaf through which oxygen and carbon dioxide can move

photosystem

cluster of chlorophyll and proteins found in thylakoids

pigment

Light-absorbing molecule

chlorphyll

the green color pigment in plants that trap sunlight for photosynthesis.

grana

stacks of thylakoids

light-dependent reactions

reactions of photosynthesis that use energy from light to produce ATP and NADPH

electron transport chain

A sequence of electron carrier molecules (membrane proteins) that shuttle electrons

calvin cycle

reactions of photosynthesis in which energy from ATP and NADPH is used to build high-energy compounds (glucose) from carbon dioxide

stroma

fluid portion of the chloroplast; outside of the thylakoids

chemiosmosis

A process for synthesizing ATP using the energy of an electrochemical gradient and the ATP synthase enzyme.

thylakoid

A flattened membrane sac inside the chloroplast, used to convert light energy into chemical energy.