D- Continuity and Change

DNA replication

The process of making exact copies of DNA sequences during cell division.

Semi-conservative replication

A type of DNA replication where each new DNA molecule consists of one old strand and one new strand.

Helicase

An enzyme that unzips the DNA by breaking hydrogen bonds.

DNA polymerase

An enzyme that builds new DNA strands according to base-pairing rules.

PCR (Polymerase Chain Reaction)

A technique used to amplify small amounts of DNA using thermal cycling.

Thermal cycling

The process in PCR consisting of denature, anneal, and extend stages to replicate DNA.

Gel electrophoresis

A method used to separate DNA fragments by size for comparison.

Transcription

The process where RNA polymerase unzips DNA and builds a strand of mRNA.

Codons

Three-base sequences on mRNA that specify particular amino acids.

tRNA

Transfer RNA that brings amino acids to ribosomes during translation.

Genetic code

The set of rules defining how codons correspond to amino acids, which is universal across living organisms.

Point mutations

Alterations in DNA where one base is changed, potentially impacting protein function.

SNPs (Single-Nucleotide Polymorphisms)

Variations at a single nucleotide position in DNA, which may be synonymous or nonsynonymous.

Frameshift mutations

Mutations caused by insertions or deletions of bases that change the reading frame of codons.

Cytokinesis

The process in which a cell divides into two at the end of cell division.

Mitosis

A type of cell division that results in two identical daughter cells.

Meiosis

A type of cell division that produces four unique haploid cells for sexual reproduction.

Crossing over

A process during meiosis that increases genetic variability by exchanging DNA between homologous chromosomes.

Osmosis

The movement of water from an area of low solute concentration to an area of high solute concentration.

Hypertonic solution

A solution with a higher concentration of solutes outside the cell, causing water to leave the cell.

Hypotonic solution

A solution with a lower concentration of solutes outside the cell, causing water to enter the cell.

Eukaryotic organisms

Organisms with complex cells that reproduce sexually to increase genetic variation.

Mendelian inheritance

The patterns of inheritance described by Gregor Mendel, involving dominant and recessive traits.

Alleles

Different versions of a gene that can be dominant, recessive, or co-dominant.

Homeostasis

The regulation of internal conditions in an organism to maintain stability.

Negative feedback

A mechanism that helps regulate biological systems by counteracting changes.

Natural selection

The process where organisms better adapted to their environment tend to survive and reproduce more successfully.

Ecosystem stability

The ability of an ecosystem to maintain its structure and function over time despite disturbances.

Climate change

Long-term changes in temperature and weather patterns, often driven by human activities.

Carbon sequestration

The process of capturing and storing atmospheric carbon dioxide to mitigate climate change.

Biomagnification

The process by which pollutants increase in concentration as they move up the food chain.

Rewilding

Restoration of ecosystems by reintroducing species and natural processes.

Ecological succession

The gradual process of change and replacement in an ecological community over time.