Chemistry and Cells
This type of weak attraction between a partial positive hydrogen and a partial negative oxygen allows water to move against gravity via transpiration.
What is a hydrogen bond?
This term describes the strength of the attraction between an enzyme's active site and its specific substrate.
What is enzyme affinity?
This three-stage process involves reception, transduction, and a cellular response, often amplified by secondary messengers like cAMP.
What is a signal transduction pathway?
This event in Prophase I of meiosis increases genetic variation by exchanging DNA between non-sister chromatids of homologous chromosomes.
What is crossing over?
A sudden reduction in population size due to a natural disaster that leaves a small, non-representative group of survivors is this type of genetic drift.
What is the bottleneck effect?
As a cell grows in size, this mathematical ratio decreases, making it harder for the cell to eliminate waste and acquire resources efficiently.
What is the surface-area-to-volume ratio?
During the light-dependent reactions, this process splits water to provide electrons for Photosystem II, releasing oxygen as a byproduct.
What is photolysis?
These specific points in the cell cycle (G1, G2, and M) involve cyclins and CDKs to ensure the cell is ready for the next phase of division.
What are checkpoints?
This statistical test is used to determine if the difference between observed and expected phenotypic ratios in a genetic cross is due to chance or a significant factor.
What is the Chi-Square (X2) test?
In a population of 100 individuals, if 16 show the recessive phenotype, this is the frequency of the dominant allele (p) according to Hardy-Weinberg.
What is 0.6? (q2 = 0.16, q = 0.4 and p = 1 - 0.4 = 0.6)
If a plant cell is placed in a solution where the solute concentration is much higher than the cell's interior, this process will cause the plasma membrane to pull away from the cell wall.
What is plasmolysis?
This mechanism uses the H+ gradient established by the Electron Transport Chain to power the phosphorylation of ADP via ATP Synthase.
What is chemiosmosis?
DNA methylation and histone acetylation are examples of this type of regulation, which alters gene expression without changing the DNA sequence.
What is epigenetic inheritance?
If two genes have a recombination frequency of 15%, they are said to be this many map units (centimorgans) apart on the same chromosome.
What is 15 map units?
This type of speciation occurs without a physical geographic barrier, often due to polyploidy or habitat differentiation within the same area.
What is sympatric speciation?
Calculate the water potential (Ѱ) of a cell with a solute potential of -4.5 bars and a pressure potential of 1.5 bars.
What is -3.0 bars?
A molecule that binds to a site other than the active site, causing a conformational change that prevents substrate binding, is this type of inhibitor.
What is a non-competitive (or allosteric) inhibitor?
In prokaryotes, this cluster of genes is regulated by a single promoter and an operator; the trp version is "repressible" while the lac version is "inducible."
What is an operon?
This phenomenon occurs when a single genotype produces different phenotypes in response to different environmental conditions, such as hydrangea color changing with soil pH.
What is phenotypic plasticity?
On average, only this percentage of energy is transferred from one trophic level to the next, with the rest lost as heat or metabolic waste.
What is 10%?
This theory explains the origin of mitochondria and chloroplasts, citing their double membranes, circular DNA, and independent ribosomes as evidence.
What is the Endosymbiotic Theory?
These proteins, found in the inner mitochondrial membrane of hibernating mammals, allow protons to leak back into the matrix without making ATP, generating heat instead.
What are uncoupling proteins (e.g., Thermogenin)?
This eukaryotic post-transcriptional process allows one gene to code for multiple different proteins by including or excluding specific exons.
What is alternative RNA splicing?
The failure of homologous chromosomes to separate in Meiosis I or sister chromatids in Meiosis II, often leading to conditions like Trisomy 21.
What is nondisjunction?
Removing this type of species from an ecosystem causes a dramatic "trophic cascade" because they exert disproportionate control on the community structure.
What is a keystone species?