Biology EOC Review

Aerobic

process that requires oxygen

Amino Acid

compound with an amino group on one end and a carboxyl group on the other end

Anaerobic

process that does not require oxygen

Aquaporin

water channel protein in a cell

ATP

compound used by cells to store and release energy

Carbohydrate

compound made of carbon, hydrogen, and oxygen atoms; types of nutrients that are the major source of energy to the body

Cellular Respiration

process that releases energy by breaking down glucose and other food molecules in the presence of oxygen

Concentration Gradient

the gradual change in the concentration of solutes in a solution as a function of distance through a solution.

Differentiation

process by which cells become specialized in structure and function

Diffusion

process by which particles tend to move from an area where they are more concentrated to an area where they are less concentrated

Equilibrium

the condition of achieving balanced thereby resulting in a stable system

Eukaryote

organism whose cells contain a nucleus

Facilitated Diffusion

process of diffusion in which molecules pass across the membrane through cell membrane channels

Fermentation

process by which cells release energy in the absence of oxygen

Glycolysis

first set of reactions in cellular respiration in which a molecule of glucose is broken into two molecules of pyruvic acid

Homeostasis

relatively constant internal physical and chemical conditions that organisms maintain

Hypertonic

when comparing two solutions, the solution with the greater concentration of solutes

Hypotonic

when comparing two solutions, the solution with the lesser concentration of solutes

Isotonic

when the concentration of two solutions is the same

Krebs Cycle

second stage of cellular respiration in which pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions

Lipid

macromolecule made mostly from carbon and hydrogen atoms; includes fats, oils, and waxes

Lipid Bilayer

flexible double-layered sheet that makes up the cell membrane and forms a barrier between the cell and the surroundings

Metabolism

the combination of chemical reactions through which an organism builds up or breaks down materials

Monomer

small chemical unit that makes up a polymer

Nucleic Acid

macromolecule containing hydrogen, oxygen, nitrogen, carbon, and phosphorus

Nucleotide

subunit of which nucleic acids are composed; made up of a 5-carbon sugar, phosphate group, and a nitrogenous base

Osmosis

diffusion of water through a selectively permeable membrane

Osmotic Pressure

pressure that must be applied to prevent osmotic movement across a selectively permeable membrane

Polymer

molecule composed of many monomers; makes up macromolecules

Prokaryote

unicellular organism that lacks a nucleus

Protein

macromolecule that contains carbon, hydrogen, oxygen, and nitrogen; needed by the body for growth and repair

Selectively Permeable

property of biological membranes that allows some substances to pass across it while others cannot; also called semipermeable membrane

Stem Cell

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

Anticodon

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

Apoptosis

process of programmed cell death

Asexual Reproduction

process of reproduction involving a single parent that results in offspring that are genetically identical to the parent

Base Pairing

principle that bonds in DNA can form only between adenine and thymine and between guanine and cytosine

Catalyst

substance that speeds up the rate of a chemical reaction

Cell Cycle

series of events in which a cell grows, prepares for division, and divides to form two daughter cells

Cell Division

process by which a cell divides into two daughter cells

Chromosome

threadlike structure of DNA and protein that contains genetic information; in eukaryotes, chromosomes are found in the nucleus; in prokaryotes, they are found in the cytoplasm

Codon

group of three nucleotide bases in mRNA that specify a particular amino acid to be incorporated into a protein

Crossing-Over

process in which homologous chromosomes exchange portions of their chromatids during meiosis

Diploid

term used to refer to a cell that contains two sets of homologous chromosomes

DNA Polymerase

principal enzyme involved in DNA replication

Enzyme

a biological catalyst and is almost always a protein. It speeds up the rate of a specific chemical reaction in the cell.

Gamete

sex cell

Genetic Code

collection of codons of mRNA, each of which directs the incorporation of a particular amino acid into a protein during protein synthesis

Haploid

term used to refer to a cell that contains only a single set of genes

Homologous

term used to refer to chromosomes in which one set comes from the male parent and one set comes from the female parent

Interphase

period of the cell cycle between cell divisions

Meiosis

process in which the number of chromosomes per cell is cut in half through separation of homologous chromosomes in a diploid cell

Messenger RNA

type of RNA that carries copies of instructions for the assembly of amino acids into proteins from DNA to the rest of the cell

Mitosis

part of eukaryotic cell division during which the cell nucleus divides

Non-Disjunction

error in meiosis in which the homologous chromosomes fail to separate properly

Replication

process of copying DNA prior to cell division

Ribosomal RNA

type of RNA that combines with proteins to form ribosomes

RNA

single-stranded nucleic acid that contains the sugar ribose

RNA Polymerase

enzyme that links together the growing chain of RNA nucleotides during transcription using a DNA strand as a template

Sexual Reproduction

type of reproduction in which cells from two parents unite to form the first cell of a new organism

Substrate

reactant of an enzyme-catalyzed reaction

Telomere

repetitive DNA at the end of a eukaryotic chromosome

Tetrad

structure containing four chromatids that forms during meiosis

Transcription

synthesis of an RNA molecule from a DNA template

Transfer RNA

type of RNA that carries each amino acid to a ribosome during protein synthesis

Translation

process by which the sequence of bases of mRNA is converted into the sequence of amino acids of a protein

Allele

one of different forms of a gene

Autosome

chromosome that is not a sex chromosome; also called autosomal chromosome

Biotechnology

Process of manipulating organisms, cells, or molecules to produce specific products

Codominance

situation in which the phenotypes produced by both alleles are completely expressed

DNA fingerprinting

tool used by biologists that analyzes an individual's unique collection of DNA restriction fragments; used to determine whether two samples of genetic material are from the same person

Ethics

the branch of knowledge that deals with moral principles

Frameshift mutation

Mutation that shifts the "reading frame" of the genetic message by inserting or deleting a nucleotide

Gel electrophoresis

Procedure used to separate and analyze DNA fragments by replacing a mixture of DNA fragments at one end of a porous gel and applying an electrical voltage to the gel

Genetic engineering

the artificial manipulation, modification, and recombination of DNA or other nucleic acid molecules in order to modify an organism or population of organisms

Genotype

genetic makeup of an organism

Germline

the specialized cell lineage containing and transmitting genetic information from generation to generation

Heterozygous

having two different alleles for a particular gene

Homozygous

having two identical alleles for a particular gene

Hybrid

offspring of crosses between parents with different traits

Incomplete dominance

situation in which one allele is not completely dominant over another allele

Independent assortment

one of Mendel's principles that states that genes for different traits can segregate independently during the formation of gametes

Karyotype

Micrograph of the complete diploid set of chromosomes grouped together in pairs, arranged in order of decreasing size

Mutagen

Chemical or physical agents in the environment that interact with DNA and may cause a mutation

Mutation

Change in the genetic material of a cell

Pedigree

Chart that shows the presence or absence of a trait according to the relationships within a family across several generations

Phenotype

physical characteristics of an organism

Point mutation

Gene mutation in which a single base pair in DNA has been changed

Polygenic traits

trait controlled by two or more genes

Polymerase chain reaction

The technique used by biologists to make many copies of a particular gene

Polyploidy

Condition in which an organism has extra sets of chromosomes

Principle of dominance

Mendel's second conclusion, which states that some alleles are dominant and others are recessive

Probability

likelihood that a particular event will occur

Punnett square

diagram that can be used to predict the genotype and phenotype combinations of a genetic cross

Recombinant DNA

DNA produced by combining DNA from different sources

Restriction enzyme

Enzyme that cuts DNA at a sequence of nucleotides

Sex chromosome

one of two chromosomes that determines an individual's sex

Sex-linked gene

gene located on a sex chromosome

Trait

specific characteristic of an individual

Adaptive radiation

process by which a single species or a small group of species evolves into several different forms that live in different ways