Cells
This ecological concept describes the accumulation of toxins at higher trophic levels in a food chain.
What is biomagnification
This mechanism of evolution occurs when random changes in allele frequency are more pronounced in small populations.
What is genetic drift
This enzyme relieves the torsional strain ahead of the replication fork by cutting and rejoining DNA strands to prevent supercoiling.
What is topoisomerase
This type of transport requires no energy and moves substances down their concentration gradient through a membrane protein.
What is facilitated diffusion
A cross between a dominant phenotype individual of unknown genotype and a homozygous recessive individual to determine the unknown genotype.
What is a test cross
The maximum population size an environment can sustain long-term, represented as K in population equations.
What is carrying capacity
The concept that evolution occurs in rapid bursts followed by long periods of stasis.
What is punctuated equilibrium
the type of inheritance that governs blood types
What is multiple alleles
The addition of excess nutrients to an aquatic ecosystem, leading to algal blooms and oxygen depletion.
What is eutrophication
the type of bond that holds the sugars and the phosphates together on the sides of the DNA "ladder"
What is phosphodiester
These structures between animal cells allow ions and small molecules to pass directly from cell to cell.
What is gap junctions
the explanation for why identical twins with identical DNA sequences may display some differences
What is epigenetic inheritance (DNA methylation & acetylation)
This condition, required for Hardy-Weinberg equilibrium, means no new alleles are introduced into the population from outside.
What is no gene flow
In transcription, RNA polymerase reads the template strand in this direction to produce mRNA.
What is 3' --> 5'
Transfer of bacterial genetic information horizontally through viruses
What is transduction
Two genes are located 20 map units apart on the same chromosome. In a testcross, what proportion of offspring would you expect to show recombinant phenotypes?
What is 20%
In nitrogen cycling, this process converts nitrate (NO₃⁻) back into N₂ gas, removing fixed nitrogen from the ecosystem.
What is denitrification
When two species evolve in response to each other over time, such as a predator and its prey, this is called what?
What is the coevolution
In the lac operon, the repressor protein cannot bind to the operator when this molecule is present.
What is allolactose (lactose)