Biology Final - All Terms

Cellular Respiration Equation

6O₂ + C₆H₁₂O₆ → 6CO₂ + 6H₂O + energy

aerobic

requiring oxygen

anerobic

does not require oxygen

glycolysis

first set of reactions in cellular respiration during which a molecule of glucose is broken into 2 molecules of pyruvic acid

NAD+

electron carrier involved in glycolysis

Krebs Cycle (Citric Acid Cycle)

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

matrix

innermost compartment of the mitochondrion

fermentation

process by which cells release energy in the absence of oxygen

cell division

process in which a cell divides into two new daughter cells

asexual reproduction

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

sexual reproduction

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

chromosome

threadlike structure within the nucleus that contains genetic information that is passed on from one generation to the next

chromatid

one of two identical “sister” parts of a duplicated chromosome

chromatin

substance found in eukaryotic chromosomes that consists of DNA tightly coiled around histones

centromere

region of a chromosome where the two sister chromatids attach

cell cycle

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

centriole

structure in an animal cell that helps to organize cell division

mitosis

part of eukaryotic cell division during which the cell nucleus divides

interphase

period of the cell cycle between cell divisions in which the cell grows

prophase

first and longest phase of mitosis in which the genetic material inside the nucleus condenses and the chromosomes become visible

metaphase

phase of mitosis in which the chromosomes line up across the center of the cell

anaphase

phase of mitosis in which the chromosomes separate and move to opposite ends of the cell

telophase

phase of mitosis in which the distinct individual chromosomes begin to spread out into a tangle of chromatin

cytokinesis

division of the cytoplasm to form two separate daughter cells

growth factor

one of a group of external regulatory proteins that stimulate the growth and division of cells

cyclin

a family of proteins that regulates the cell cycle in eukaryotic cells

apoptosis

programmed cell death

cancer

disorder in which some of the body’s cells lose the ability to control growth

tumor

mass of rapidly dividing cells that can damage surrounding tissue

genetics

scientific study of heredity

fertilization

process in sexual reproduction in which male and female reproductive cells join to form a new cell

trait

specific characteristic of an individual

hybrid

offspring of crosses between parents with different traits

gene

sequence of DNA that codes for a protein and thus determines a trait; factor that is passed from parent to offspring

allele

one of a number of different forms of a gene

principle of dominance

there is always one trait that is dominant and one that is recessive

segregation

separation of alleles during gamete formation

gamete

sex cell, germ cell

homozygous

having two identical alleles for a particular gene, TT or tt

heterozygous

having two different alleles for a particular gene, Tt

phenotype

physical characteristics of an organism

genotype

genetic makeup of an organism

Punnet Square

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

independent assortment

genes for different traits separate independently from each other during the formation of gametes

incomplete dominance

one allele is not completely dominant over the other

codominance

the phenotypes produced by both alleles are completely expressed

multiple alleles

a gene that has more than two alleles

polygenic trait

trait controlled by two or more genes

homologous

chromosomes that are similar in size, shape, genes they carry, or some other characteristic

diploid

a cell that has a full amount of chromosomes, in humans it is 46

haploid

a cell that has half the amount of chromosomes, in humans it is 23

meiosis

cell division in which 4 haploid gametes are created

crossing over

process in which homologous chromosomes exchange portions of genetic information during prophase I of meiosis

transformation

process in which one strain of bacteria is changed by a gene or genes from another strain of bacteria

bacteriophage

a kind of virus that infects bacteria

base pairing

a principle in DNA that adenine can only pair with thymine and guanine can only pair with cytosine

nucleotide

subunit of which nucleic acids are composed;

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

nucleic acids

macromolecules containing carbon, hydrogen, oxygen, nitrogen, and phosphorous (CHONP)

X-ray crystallography

the process Rosalind Franklin used to take photo 51, revealing the structure of DNA

antiparallel strands

the two strands of DNA run in opposite directions, one running from 5’ to 3’, the other running from 3’ to 5’

hydrogen bonds

weak attraction between a hydrogen atom and another atom, this is used to bond the bases together

replication

process of copying DNA prior to cell division

helicase

an enzyme that “unzips” DNA in DNA replication

DNA polymerase

an enzyme that binds to a primer and adds on new nucleotides in the 5’ to 3’ direction

telomere

repetitive DNA at the end of a eukaryotic chromosome, like the “caps” on the end of chromosomes

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

ribosomal RNA

type of RNA that helps tRNA add on amino acids + combines with proteins to form ribosomes

transfer RNA

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

transcription

synthesis of a RNA molecule to form mRNA

RNA polymerase

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

promoter

specific region of a gene where RNA polymerase can bind and begin transcription

intron

part of pre-mRNA that is removed

exon

part of pre-mRNA that is expressed and codes for a protein

polypeptide

long chain of amino acids that make proteins

genetic code

the sequence of nucleotides in mRNA that determines the amino acid sequence that code for proteins

codon

a group of three nucleotide bases in mRNA that specify a particular amino acid

translation

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

anticodon

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

gene expression

the information encoded in a gene is turned into a function

mutation

change in the genetic material of a cell, can be harmful and beneficial

point mutation

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

frameshift mutation

mutation that shifts the “reading frame” of the genetic message by inserting or deleting a nucleotide

mutagen

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

polyploidy

condition in which an organism has extra sets of chromosomes

operon

in prokaryotes, a group of adjacent genes that shares a common operator and promoter and are transcribed into a single mRNA

operator

short DNA region, adjacent to the promoter of a prokaryotic operon, that binds repressor proteins responsible for controlling the rate of transcription of the operon

differentiation

process in which cells become specialized in structure and function

evolution

change over time; the process by which modern organisms have descended from ancient organisms

artificial selection

selective breeding of plants and animals to promote the occurrence of desirable traits in offspring

adaptation

heritable characteristic that increases an organism's ability to survive and reproduce in an environment

fitness

how well an organism can survive and reproduce in its environment

natural selection

process by which organisms that are most suited to their environment survive and reproduce most successfully; also called survival of the fittest

common ancestry

different species and animals share a familial link to a single species or animal

biogeography

the study of past and present distribution of organisms

homologous structure

structures that are similar in different species of common ancestry

vestigial structure

structure that is inherited from ancestors but has lost much or all of its original function

analogous structure

body parts that share a common function, but not structure

speciation

formation of a new species

phylogeny

study of evolutionary relationships among organisms

clade

evolutionary branch of a cladogram that includes a single ancestor and all its descendants