A type of embryonic development in deuterostomes in which the planes of cell division that transform the zygote into a ball of cells are either parallel or perpendicular to the polar axis, thereby aligning tiers of cells one above the other.
A method of determining the age of fossils and rocks using half-lives of radioactive isotopes.
An isotope, an atomic form of a chemical element, that is unstable; the nucleus decays spontaneously, giving off detectable particles and energy.
A method paleontologists use for determining the ages of rocks and fossils on a scale of absolute time, based on the half-life of radioactive isotopes. On or in a cell, a specific protein molecule whose shape fits that of a specific molecular messenger, such as a hormone.
The intensity of the receptor potential determines the frequency of action potentials traveling to the nervous system.
Altruistic behavior between unrelated individuals; believed to produce some benefit to the altruistic individual in the future when the current beneficiary reciprocates.An offspring whose phenotype differs from that of the parents.A DNA molecule made in vitro with segments from different sources.Taken together, a total of 15% of American adults now report that they have used online dating sites and/or mobile dating apps, up from the 11% who reported doing so in early 2013.1 This growth has been especially pronounced for two groups who IMPORTANT: Do not mail anything to this address including checks, money orders or pictures.A specific sequence of nucleotides at which a restriction enzyme cleaves a DNA molecule.The idea that specific mating adaptations become fixed in a population and form the basis of species identification.← BACK A bacterial plasmid carrying genes that confer resistance to certain antibiotics.The concept that in certain (r-selected) populations, a high reproductive rate is the chief determinant of life history.Please mail any official Interracial People is the premier online interracial dating service.Interracial singles are online now in our large online biracial dating community.