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99 terms

Biology Unit 2

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Autotrophs
organism that makes its own food, often by photosynthesis (plants, algae, etc.)
Producers
organism that makes organic food molecules from raw materials such as CO2, H2O
Chlorophyll
green pigment located in chloroplasts of plants, algae and prokaryotes. helps to convert sunlight to chemical energy
Stomata
pore surrounded by guard cells in epidermis of leaf. when open, CO2 enters a leaf, and water and O2 exit
Stroma
fluid in chloroplast surrounding thykaloid membrane. synthesis of molecules from CO2 to water. where sugars are made during Calvin Cycle
Thykaloids
disk shaped sac in in chloroplast. contain chlorophyll and enzymes of light reactions of photosynthesis
Granum
stack of hollow disks of thykaloid membrane in chloroplast
Photosynthesiss
process by which plants use light energy to make sugars from CO2 and water
Calvin Cycle
second of two stages of photosynthesis. cyclic series of chemical reactions that occur in stroma of a chloroplast using carbon and ATP and NADPH
Carbon Fixation
incorporation of carbon from atmospheric CO2 into carbon of organic compounds
Light Reactions
first of two stages in photosynthesis. solar energy is absorbed and converted to chemical energy in form of ATP and NADPH. power Calvin Cycle
Wavelength
distance between crests of adjacent waves
Photophosphorylation
production of ATP by chemiosmosis during light reactions of photosynthesis
Greenhouse Effect
warming of atmosphere caused by CO2, CH4 and other gases that absorb infrared radiation and slow it's escape from earth's surface
Global Warming
slow rise in earth's surface temperature
Self-fertilize
fusion of sperm and egg produced by the same organism
Cross-fertilization
fusion of sperm and egg derived from two different individuals
Hybrid
offspring of parents of two different species. heterozygous for at least one pair of genes
Cross
mating of two sexually reproducing individuals
P Generation
parent individuals from which offspring are derived in studies in inheritance
F1 Generation
offspring of two parental individuals
F2 Generation
offspring of F1 generation
Monohybrid Cross
experimental mating of individuals differing
Allele
alternative version of a gene
Homozygous
having two identical alleles for a given gene
Heterozygous
having two different alleles for a given gene
Recessive Allele
allele that has noticeable effect on phenotyope of a gene when individual is heterozygous for that gene
Dominant Allele
allele that determines the phenotype of a gene when individual is heterozygous for that gene
Law of Segregation
rule of inheritance that individuals have two alleles for each gene and that when gametes form by meiosis, the two alleles separate, each resulting gamete ending up with only one allele of each gene
Punnett Square
diagram used in the study of inheritance to show the results of random fertilization
Phenotype
expressed traits of an organism
Genotype
genetic makeup of an organism
Dihybrid Corss
experimental mating of individuals differing
Law of Independent Assortment
rule in inheritance when gametes form during meiosis, each pair of alleles for a particular characteristic segregate independently of other pairs
Testcross
mating between an individual of unknown genotype for a particular characteristic and an individual that is homozygous recessive for same characteristic
Pedigree
family tree representing occurrence of heritable traits in parents and offsrping
Cystic Fibrosis
genetic disease that occurs in people with two copies of a certain recessive allele
Achondroplasia
form of human dwarfism caused by single dominant allele. exception
Huntington's Disease
genetic disease caused by dominant allele. exception
Complete Dominance
type of inheritance in which one phenotype is dominant
Incomplete Dominance
neither phenotype is dominant (red + pink = white)
Codominant
neither phenotype dominant over other, causing both traits to show
Pleiotropy
one gene influencing many characteristics (Sickle Cell Anemia)
Hemophilia
genetic disease caused by sex-linked recessive allele
red-green color blindness
sex-linked disorder involving genes of X-chromosome
Bacteriophage
virus that infects bacteria. used by Hershey and Chase to show that DNA is genetic material
Nucleotides
organic monomer consisting of five-carbon sugar covalently bonded to a nitrogenous base. building block of nucleic acids
Polynucleotides
polymer made up of many nucleotides covalently bonded together
Thymine
single ring nitrogenous base found in DNA. T plus A
Cytosine
single ring nitrogenous base found in DNA and RNA. C plus G
Adenine
single ring nitrogenous base found in DNA and RNA. A plus T
Guanine
single ring nitrogenous base found in DNA and RNA. G plus C
Uracil
single ring nitrogenous base found in RNA. U plus A
Double Helix
form of DNA, referring to its two adjacent polynucleotide strands wound into a spiral shape
Watson and Crick
determined structure of ACTG, the four bases for DNA. "stole" x-ray crystallography technique from Rosalind to determine double helix structure
Rosalind
used x-ray crystallography, determined double helix shape of DNA
Transcription
DNA transcribed to RNA in the nucleus. word is a codon, consisting of three letters
Translation
switching from nucleotide "language" to amino acid "language." occurs in ribosome. RNA translated into protein
Codons
three-nucleotide sequence in mRNA that specifies a particular amino acid signal
Genetic Code
set of rules that dictates the correspondence between RNA codons in an mRNA molecule and amino acids in protein
RNA Polymerase
enzyme that links together the growing chain of RNA nucleotides during transcription
Promoter
specific nucleotide sequence in DNA located at the start of a gene that is the binding siet for RNA polymerase and where transcription begins
Terminator
sequence of nucleotides in DNA that marks the end of a gene
Messenger RNA (mRNA)
ribonucleic acid that encodes genetic info from DNA and conveys it to ribosomes, where translation occurs, creating amino acid sequences
Introns
in eukaryotes, noncoding portion of gene that is excised from RNA transcript
Exons
in eukaryotes, coding portion of a gene
RNA Splicing
removing of introns and joining of exons in eukaryotic DNA, forming mRNA molecul with continuous coding sequence
Anticodon
on tRNA molecule, specific sequence of three nucleotides that is complementary to a codon triplet on mRNA
Transfer RNA (tRNA)
ribonucleic acid that functions as an interpreter in translation
Ribosomal RNA (rRNA)
ribonucleic acid that together with proteins makes up ribosomes
Stop Codon
in mRNA, one of three triplets (UAG, UAA, UGA) that signal gene transcription to stop
Mutation
change in nucleotide sequence of an organism's DNA
Lytic Cycle
viral replication cycle resulting in the release of new viruses by lysis
Lysogenic Cycle
bacteriophage replication cycle in which viral genome is incorporated into bacterial host chromosome as prophage
Gene Expression
info flow from genes to proteins, mainly at transcription
Cloning
produced asexually, genetically identical to parent. used for endangered species
Differentiation
cell specialization in structure and function
Ectoderm
outside (skin and nervous system)
Mesoderm
middle (muscle, heart)
Endoderm
inside (gut tube)
Nuclear Transplantation
replace nucleus of egg cell with nucleus of adult somatic cell
Reproductive Cloning
implant embryo in surrogate mother
Therapeutic Cloning
remove embryonic stem cells
Enhancers
eukaryotic DNA sequence that stimulates transcription of a gene
Silencers
eukaryotic DNA sequence that inhibits the start of gene transcription
Adult Stem Cells
cell present in adult tissues that generates replacements for nondividing differentiated cells
Proto-oncogene
normal gene that can be converted to a cancer-causing gene
Oncogene
cancer-causing gene
Tumor-suppressor Genes
gene whose products inhibits cell division, preventing uncontrolled cell growth
Carcinogen
cancer-causing agent, as radiation or chemical
DNA Profiling
procedure that analyzes DNA fragments to determine whether they come from a specific individual
Genetic Engineering
direct manipulation of genes for practical purposes
Gene Cloning
production of multiple copies of a gene
Recombinant DNA
DNA molecule carrying genes derived from two or more sources
Plasmids
small ring of independently replicating DNA separate from the main chromosomes
Vector
piece of DNA, usually a plasmid or viral genome, that is used to move genes from one cell to another
DNA Ligase
enzyme, essential for DNA replication, that catalyzes the covalent bonding of adjacent DNA strands
Genomic Library
set of DNA segments representing an organism's entire genome
Insulin
protein hormone, produced through recombinant DNA