evolution, genes, environment and behavior Flashcards
kapittel 3
evolution (biological)
gradual change over time in organic life from one form into another.
natural selection
characteristics that increase the likelihood of survival and reproduction within a particular environment will be preserved in the population and therefore become more frequent over time.
mutations
random events and accidents in gene reproduction during the division of cells.
dominant
the particular characteristic tat it controls will be displayed.
recessive
the characteristics will not show up unless the partner gene inherited from the other parent is also recessive.
allele
alternative forms of gene that produce different characteristics.
polygenic transmission
when a number of gene pairs combine their influences to create a single phenotypic traits.
genotype
the specific and complete genetic make-up of the individual.
phenotype
the individual’s outward observable characteristics.
adaptations
physical or behavioral changes that allow organisms to meet recurring environmental challenges to their survival, thereby increasing their reproductive ability.
genes
functional segments of the long molecule deoxyribonucleic acid, or DNA, that code for proteins.
chromosome
a single- or double- stranded structure comprising proteins and deoxyribonucleic acid (DNA)
somatic
a somatic cell is any cell forming the body of an organism; they do not contain reproductive cells.
diploid
the number of chromosomes carried by a cell with two complete sets of chromosomes (one from each parent) is called the diploid number of chromosomes.
gametes
sex cels (eggs and sperm)
haploid
the number of chromosomes carried by a gamete cell, which is half the number of chromosomes carried in a typical cell, is called the haploid number of chromosomes.
zygote
a fertilized egg containing 46 pairs of chromosomes.