science Flashcards
DNA
deoxyribonucleic acid, a self-replicating material present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.
nucleotide
in a nucleic-acid chain, a subunit that consists of a sugar a phosphate and a nitrogenous base.
Chargaff’s Rules
Any cell should have a 1:1 ratio the amount of guanine should equal cytosine
Watson and Crick
concluded that dna looks like a long twisted ladder.
Rosalind Franklin
franklin used X-Ray diffraction to make images of dna that helped reveal the structure of dna.
mutations
a change in the nitrogenous base sequence of a gene or DNA molecule.
adaptations
a change or the process of change by which an organism or species becomes better suited to its environment.
species
a group of organisms that are closely related and can mate to produce fertile offspring
evalution
the process in which inherited characteristics within a population change over generations such that new species sometimes arise
fossiles
the remains or physical evidence of a past creature.
fossil record
a historical sequence of life indicated by fossils found in layers of the earths crust.
Charles Darwin
founder of evolution
trait
a genetically determined characteristic
selective breeding
the human practice of breeding animals or plants that have a certain desired characteristic
natural selection
the process by which individuals that are better adapted to their environment survive and reproduce more successfully then less adapted
generation time
the period between the birth of one generation to the next
speciation
the formation of new species as a result in evaluation
primates
a type of mammal characterized by oposable thumbs and binocular vision
hominid
a type of primates characterized by bidedalism lack of tail
homo sapiens
the modern human
