Evolution of tolerance Flashcards
what is the significance in studying Evolution of tolerance resistance?
contribute to the development of ecological evolutionary theories
= more effective approaches for minimizing undesirable consequences of pollutant stress.
What is fecundity?
the ability for an organism to reproduce
what factors can influence fertility?
influenced by fertilization success, age, nutrition, hormones and behavior
what does tolerance signify in terms of environmental stress?
an organism’s ability to function successfully during exposure to an environmental stress
how can tolerance be catergorized based on duration?
short-term tolerance
long-term tolerance-continued growth and reproduction
What is ‘cross resistance’ in context of environmental agents?
cross resistance is resistance to more than 1 environmental agent achieved by a single mechanism
Define genetic drift
Genetic Drift is a random change in allele frequencies in a population, accelerated at low effective population size
what does genetic drift casue?
may result in the loss of beneficial alleles or fixation of harmful alleles
what causes genetic variation?
caused by independent assortment of chromosomes, crossing over, random fertilization and mutation
Name Mechanisms of evolution of resistance to chemicals
detoxification,
alteration of the site of action,
reduced penetration into the organism, sequestration,
and behavioral avoidance.
How is resistance of metals achieved in cells?
metal trafficking pathways have evolved
what do metal trafficking pathways involve?
sequestration by metal detoxification systems to prevent the toxic effects of metals.
Define mechanisms of resistance in malignant cells
increased DNA repair,
decreased drug activation,
binding of free radicals,
decreased drug uptake and increased efflux,
and changes in target enzymes.
What is the relationship between Genetic Variation and the ability of a population to adapt?
Less genetic variation could decrease the ability of a population to adapt to changing environmental conditions
what are the potential impacts of low reproduction rates in context of environmental stress?
Low reproduction rates may indicate a higher sensitivity to habitat loss stress
