27 terms

Anth 21 Lecture 4

bio-anth Westin
cells that do not contain nuclei 3.4 bya
organisms made up of one or more cells that have a nucleus and membrane-bound organelles 1.5 bya
Somatic Cells
any cell in multicellular organism except an egg or sperm (mitosis- growth or repair)
reproductive cells, have only half the number of chromosomes as body cells (meiosis-reproduction)
subunits of nucleic acid formed from a simple sugar, a phosphate group, and a nitrogenous base- Adenine & Thymine Guanine & Cytosine
a specific sequence of three adjacent bases on a strand of DNA or RNA that provides genetic code information for a particular amino acid
threadlike structures made of DNA molecules that contain the genes (coiled DNA prior to cell division)
Homologous Chromosomes
Chromosomes that are similar in size, shape, and genetic content (same size/location of centromere
genes for same traits
not identical)
an organism or cell having two sets of chromosomes or twice the haploid number (# chromosomes in somatic cells)
An organism or cell having only one complete set of chromosomes (Gametes)
one of two identical strands into which a chromosome splits during mitosis
a specialized condensed region of each chromosome that appears during mitosis where the chromatids are held together to form an X shape
any chromosome that is not a sex chromosome
Sex Chromosomes
one of the 23 pairs of chromosomes in the human, contains genes that will determine the sex of the individual
(genetics) a segment of DNA that is involved in producing a polypeptide chain (codes for a protein- occurs at a locus)
the specific site of a particular gene on its chromosome
one of the alternative forms of a gene that governs a characteristic, such as hair color
the particular alleles at specified loci present in an organism
what an organism looks like as a consequence of its genotype
having identical alleles at corresponding chromosomal loci
having dissimilar alleles at corresponding chromosomal loci
any event that changes genetic structure (change in nitrogen base ONLY source of NEW genetic material)
silent mutation
A type of base substitution mutation that changes a single nucleotide, but does not change the amino acid created.
Beneficial Mutation
is a mutation that increases fitness of the organism, or which promotes traits that are desirable. (Fuel for Natural Selection)
Deleterious Mutation
A mutation that is harmful to its host; most mutations are this. (protein is not made or does not work)
Point Mutation
mutation that effects a single nucleotide (base), usually by substituting one for another- sickle cell anemia
Frame-shift Mutation
Mutation that involves the insertion or deletion of a nucleotide (base) in the DNA sequence-codons shifted