Chapter 3 vocab Flashcards
Chromosomes
a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.
DNA
a self-replicating material that is present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.
Genotype
the genetic constitution of an individual organism
Phenotype
the set of observable characteristics of an individual resulting from the interaction of its genotype with the environment.
Mutations
the changing of the structure of a gene, resulting in a variant form that may be transmitted to subsequent generations, caused by the alteration of single base units in DNA, or the deletion, insertion, or rearrangement of larger sections of genes or chromosomes.
Gene-environment interactions
a different effect of an environmental exposure on disease risk in persons with different genotypes
identical twins; fraternal twins
identical: develop from a single fertilized egg, they have the same genome
fraternal: developing from separate fertilized ova, are genetically distinct and not necessarily of the same sex or more similar in appearance than other siblings
Glia Cells
They maintain homeostasis, form myelin in the peripheral nervous system, and provide support and protection for neurons.
Neuron: soma
contains the nucleus and keeps the entire cell alive and functioning
dendrites
a neuron’s bushy, branching extensions that receive messages and conduct impulses toward the cell body
axon
the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands
terminal buttons
Small knobs at the end of axons that secrete chemicals called neurotransmitters
