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52 terms

Science Vocab for Chapters 11 and 14

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genotype
genetic makeup, is the sequence of nucleotide bases in its DNA
Phenotype
the organisms specific traits, lies in proteins and their wide variety of functions
"One Gene-One enzyme"
this hypothesis states that the function of an individual gene is to dictate the production of a specific enzyme.
One Gene-One Polypeptide
since then, scientists have learned that most genes actually dictate the production of a single polypeptide, which may make up part of an enzyme or another kind of protein.
RNA
is any nucleic acid whose sugar is ribose rather than deoxyribose of DNA. this also differs from DNA becuase instead of having thymine, it has uracil.
Transcription
in the first step from gene to protein, DNA's nucleotide sequence is converted to the form of a single-stranded RNA molecule in a process called..
translation
converts nucleic acid language into amino acid languages. the flow of information from gene to protein is based on codons
Codon
is a three-base word that codes for one amino acid
mRNA
is transcribed from a DNA template
RNA polymerase
a transcription enzyme that links the RNA nucleotides together
Introns
noncoding regions that are found in most plant and animal genes
Exons
the coding regions of the RNA transcript-the parts of a gene that remain in the mRNA and will be translated or expressed.
RNA Splicing
process by which the introns are removed from RNA transcripts and the remaining exons are joined together, producing an mRNA molecule with a continuous coding sequence
tRNA
translates the three-letter codons of mRNA to the amino acids that make up the proteins
Anticodon
the three bases of this are complementary to a specific codon in the mRNA. During translation, the ( ) on tRNA recognizes a particular codon on mRNA by using base-pairing rules.
rRNA
the ribosome consists of two parts or subunits, each of which is made up of proteins and a considerable amount of yet another kind of RNA called....
Protein Synthesis
the chain of command originates with the information in the DNA of a gene. The DNA serves as a template, dictating transcription of a complementary strand of mRNA. in turn, mRNA specifies the sequence of amino acids in a polypeptide built with the assistance of tRNA and the rRNA of a ribosome. Finally, the proteins that form from the polypeptides determine the appearance and functioning of the cell and of the whole organism.
Mutation
is any change in the nucleotide sequence of DNA
Base Substitutions and Insertions
Base substitution- the replacement of one base or nucleotide with another. Insertion- when one or more nucleotides in a gene is usually more disastrous than the effects of a base substitution
Mutagen
physical or chemical agents that cause mutations
Evolution
is all the changes that have transformed life over an immense time
adaptation
to be an inherited characteristic that improves an organisms ability to survive and reproduce in a particular enviornment
Inheritance of Acquired Characteristics
The hypothesis that organisms' bodies change during their lifetimes by use and disuse and that these changes are inherited by their offspring
Charles Lyell
proposed that gradual and observable geologic processes such as erosioin could explain the physical features of today's earth. Applying these ideas, In harbor, darwin observed a block of land that had been underwater move upward above the water level as a result of the quake. He also collected fossils of ocean organisms high in the Andes. Darwin reasoned that earthquakes gradually lifted the rock bearing those marine fossils from the sea floor
Geologic Evidence provided by Lyell
1st: the slow processes of mountain building and erosion suggested an earth that must be very old. 2nd: these slow gradual processes occurring over vast spans of time could cause enormous change on Earth.
Malthus' Ideas
human suffering was due to the human population's potential to grow. That is, the populations can grow much faster than the rate at which supplies of food and other resources can be produced
Descent with Modification
He argued from evidence that the species of organisms living on Earth today descended from ancestral species. in other words, life has a history of change. In these different habitats over time, they accumulated different modifications, or adaptations, to diverse ways of life.
Natural Selection
( ) as the mechanism for evolution. ( ) is the process by which individuals with inherited characteristics well suited to the enviornment leave more offspring on average than do other individuals. can cause a population to change over time. "Survival of the Fittest" The result of this is adaptation. A natural process resulting in the evolution of organisms best adapted to the environment
Fossils
preserved remains or markings left by organisms that lived in the past
Rock Strata
Layers, that form when the rates of sedimentation or the types of particles forming the sediments vary over time
Fossil record
the chronological collection of life's remains in the rock layers, recorded during the passage of time.
Extinct
species that no longer exist-helping scientists reconstruct the past.
Marsupials vs Placentals in Austrailia
there are few placentals not becuase they are unable to survive. The most widely accepted hypothesis states that Austrailia's diverse marsupial species evolved from marsupial ancestors on an island content that was isolated from placental mammals
Homologous Structures
structures in species sharing a common ancestor. exp are wings, flippers, arms and forelegs and you would think that they would have different structures since they have different functions. However they do not becuase they are all variations on a common ancestral theme-one that has become adapted to different functions.
Vestigial Structures
are remanants of structures that may have had important functions in an ancestral species, but have no clear function in some of the modern descendants. Lamarck's idea of Inheritance of Acquired Characteristics account for the reduced size of vestigial structures.. Natural Selection would favor the survival and reproduction of individuals with genes for reduced versions of those structures. goosebumps are an example of this
Comparing the development of different organisms
embryos of closely related organisms often have similar stages in development. All vertebrates have an embryonic stage in which pouches appear on the sides of the throat. At this stage the embryos of frogs, fish, snakes and birds look relatively alike. However, they take on more distinctive characteristics as they continue to develop.
Molecular Comparison
if two species have genes and proteins with sequences that match closely, biologists conclude that the sequences must have been inherited from a relatively recent common ancestor. in contrast, the greater number of differences in DNA and protein sequences between species, the less likely they share as close a common ancestry
Darwin's Boldest Statement
all life forms are related. The molecular evidence includes the common genetic code shared by all species. THis genetic language has been passed along through all the branches of evolution. And, it has added to the evidence that supports evolution as an explanation for the unity and diversity of life
Antibiotics
these drugs help to cure many infections caused by bacteria.
Antibiotic Resistance
this evolves by natural selection. An antibiotic causes selection among the varying bacteria of a population, leaving those individuals that can survive the drug. While the drug kills most of the bacteria, the resistant bacteria multiply and quickly become the norm in the population rather than the exceptions. People infected with a resistant strain have no better chance of surviving than tuberculosis patients did a century ago
selective breeding
breeding that is chosen. for example: two separate species of dogs that are put together to breed another type of dog.
Allele
one of two alternate forms of a gene that can have the same locus on homologous chromosomes and are responsible for alternative traits. one allele from your mother, and one from your father.
Structure of DNA
composed of nucleotides that are composed of a phosphate, a deoxyribose sugar and a nitrogen base (adenine, thymine, guanine, cytosine). Nucleotides are connected by covalent bonds.
Shape of DNA
double helix
Nucleotide
base unit of DNA. In other words, it forms DNA
Clade
each evolutionary branch in a phylogenetic tree
Gene
unit of inherited information in DNA
Derived Characters
unique features that unite the organisms as a clade
cladogram
a phylogenetic diagram that specifies the derived characters of clades
phylogenetic tree
a diagram that reflects the hypothesis of evolutionary relationships. Each branch represents a common ancestor of the species
Convergent Evolution
process by which unrelated organisms independently evolve similarities when adapting to similar environments
Analogous Structures
similar adaptations that result from convergent evolution