40 terms

Anthropology Exam 1

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adaptation
a change in physical structure, function, or behavior that allows an organism or species to survive and reproduce in a given environment
allele
one or more alternative forms of a gene
autosomes
all chromosomes, except the sex chromosomes, that occur in pairs in all somatic cells (not the gametes)
chromosomes
the strand of DNA found in the nucleus of eukaryotes that contains hundreds or thousands of genes
cline
geographic continuum of the frequency of specific biological traits
clinal distribution of traits
traits like sickle cell increase in frequency in areas where malaria is endemic, and decrease where it is not
codon
a sequence of three nitrogen bases carried by mRNA that are coded to produce specific amino acids in protein synthesis
continuous trait
one phenotypic trait that is affected by two or more genes
diploid
(of a cell or nucleus) containing two complete sets of chromosomes, one from each parent.
discrete traits
a trait controlled by one gene: you either have it or you don't
DNA
a double-stranded molecule that provides the genetic code for an organism, consisting of phosphate, deoxyribose sugar, and four types of nitrogen bases
dominant
refers to an allele that is expressed in an organism's phenotype and that simultaneously masks the effects of another allele (recessive) if another is present
eukaryotic cells
cells with internal compartments separated by membranes; nuclear envelop contains the nucleus, and the cell membranes encircles the cytoplasm; split into somatic cells and gametes
gametes
sex cells, ova and sperm, haploid, can unite with gamete of the opposite type to create a new organism
gene
the basic unit of inheritance; a sequence of DNA on a chromosome coded to produce a specific protein
gene pool
all the genetic information in a breeding population
genotype
the genetic makeup of an organism; the combination of alleles for a given gene
haploid
a cell that has a single set of unpaired chromosomes
heterozygous
having inherited two different alleles for one gene from your parents
homologous chromosomes
each set of paired chromosomes in the genome
homozygous
having inherited the same alleles for one gene from both parents
Hox genes
genes that differentiate the specific segments of the body, such as the head, tail, and limbs, during embryological development
locus
the location of a specific gene on a chromosome
karyotype
photograph of a person's chromosomes that have been arranged in homologous pairs and put in numerical order by size
meiosis
the production of gamete cells through one DNA replication and two cell (and nuclear) divisions, creation four haploid gamete cells
melanocyte
melanin-producing cells located in the skin's epidermis
microevolution
small-scale evolution, such as changes in allele frequency, that occurs from one generation to the next
macroevolution
large-scale evolution, such as a speciation event, that occurs after hundreds or thousands of generations
mitosis
the process of cellular and nuclear division that creates two identical diploid daughter cells
mtDNA
mitochondrial DNA, containing 37 genes, inherited just from the mother; heteroplasmic, meaning it can differ among different parts of the person's body and even within the same kind of cells
mutation
a random change in a gene or chromosome, creating a new trait that may be advantageous, deleterious, or neutral in its effects on the organism (point=change of one base to another, frameshift=insertion or deletion of nitrogen bases)
nucleotide
building block of DNA, made up of a phosphate group (which form connections with other ______s), a sugar, and a single nitrogen base
nucleotide bases
adenine, thymine, guanine, cytosine (in RNA, thymine is replaced with uracil)
phenotype
the physical expression of the genotype; it may be influenced by the environment
population
the gene pool of a breeding group of organisms
prokaryotic cells
cells without internal compartments sealed off by membranes; no nucleus; free-floating genetic material in the cytoplasm
recessive
an allele that is expressed in an organism's phenotype if two copies are present but masked if the dominant allele is present
replication
copying of DNA through transcription and translation
RNA (ribonucleic acid)
a single-stranded molecule involved in protein synthesis consisting of a phosphate, ribose sugar, and four nitrogen bases
speciation
when a new species is created; a species is a group of related organisms that can interbreed and produce fertile, viable offspring