MCAS Biology flashcards
MCAS Biology · Build recall with a focused review session.
33 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Monomer of proteins
- Amino acids. They join by peptide bonds into polypeptide chains that fold into proteins; the sequence of amino acids determines the protein's shape and function.
- Monomer of carbohydrates
- Monosaccharides such as glucose. They link by glycosidic bonds to form disaccharides and polysaccharides like starch, glycogen, and cellulose, used for energy and structure.
- Cell theory
- All living organisms are composed of one or more cells, the cell is the basic unit of structure and function, and all cells come from pre-existing cells.
- Prokaryote vs eukaryote
- Prokaryotes lack a membrane-bound nucleus and organelles and are typically bacteria; eukaryotes have a nucleus and membrane-bound organelles such as mitochondria and chloroplasts.
- Mitochondrion function
- The organelle where aerobic cellular respiration occurs, converting glucose and oxygen into carbon dioxide, water, and ATP, the usable energy currency of the cell.
- Chloroplast function
- The plant organelle that carries out photosynthesis, using light energy to convert carbon dioxide and water into glucose and oxygen; it contains the pigment chlorophyll.
- Ribosome function
- The site of protein synthesis, where mRNA codons are translated and tRNA delivers amino acids in order to build a polypeptide chain.
- Cell membrane structure
- A phospholipid bilayer with embedded proteins and other molecules; it is selectively permeable, controlling which substances enter and leave the cell.
- Photosynthesis equation
- 6CO2 + 6H2O + light energy yields C6H12O6 + 6O2. It occurs in chloroplasts and stores light energy as chemical energy in glucose.
- Cellular respiration equation
- C6H12O6 + 6O2 yields 6CO2 + 6H2O + ATP. Glucose is broken down to release energy that is captured in ATP molecules.
- Osmosis
- The passive diffusion of water across a membrane from an area of lower solute concentration to an area of higher solute concentration, requiring no cellular energy.
- Active transport
- Movement of substances across a membrane against their concentration gradient, requiring energy from ATP and usually a carrier protein such as a pump.
- Enzyme denaturation
- Loss of an enzyme's functional shape caused by excessive heat or extreme pH; the active site changes so the substrate no longer binds and reaction rate drops sharply.
- DNA base pairing
- In DNA, adenine pairs with thymine and guanine pairs with cytosine through hydrogen bonds, so each strand is complementary to the other.
- Transcription
- The process in which a DNA gene is copied into messenger RNA in the nucleus, allowing the genetic code to be carried to a ribosome.
- Translation
- The process at a ribosome in which mRNA codons are read and matching amino acids are joined by tRNA to form a protein.
- Frameshift mutation
- An insertion or deletion of bases that is not a multiple of three, shifting the reading frame and usually changing many amino acids downstream.
- Dominant vs recessive allele
- A dominant allele is expressed in the phenotype even when only one copy is present; a recessive allele is expressed only when two copies are present.
- Genotype vs phenotype
- Genotype is the genetic makeup (allele combination) of an organism; phenotype is the observable trait produced by that genotype and environmental influences.
- Meiosis
- Two cell divisions that produce four genetically unique haploid gametes from one diploid cell, halving chromosome number and creating variation through crossing over and independent assortment.
- Mitosis
- One cell division producing two genetically identical diploid daughter cells, used for growth, repair, and asexual reproduction.
- Sex-linked trait
- A trait controlled by a gene on a sex chromosome, usually the X; because males have only one X, recessive X-linked disorders appear more often in males.
- Natural selection
- The process by which individuals with heritable traits better suited to their environment survive and reproduce more, increasing those traits in the population over generations.
- Homologous structures
- Body parts in different species that share a common origin and similar underlying structure but may differ in function, such as the forelimbs of humans, whales, and bats.
- Species
- A group of organisms that can interbreed under natural conditions and produce fertile offspring, reproductively isolated from other such groups.
- Carrying capacity
- The maximum population size of a species that a given environment can support indefinitely, limited by food, water, space, and other resources.
- Producer vs consumer
- Producers (autotrophs) make their own food using sunlight or chemical energy; consumers (heterotrophs) obtain energy by eating other organisms.
- Ten percent energy rule
- Only about 10 percent of the energy at one trophic level is transferred to the next; the rest is lost as heat, so food chains are short.
- Mutualism
- A symbiotic relationship in which both species benefit, such as bees obtaining nectar while pollinating flowers.
- Parasitism
- A symbiotic relationship in which one organism benefits by living on or in a host, which is harmed, such as a tapeworm in a mammal's intestine.
- Carbon cycle
- The movement of carbon among the atmosphere, organisms, soil, and oceans through photosynthesis, respiration, decomposition, combustion, and fossil fuel formation.
- Binomial nomenclature
- The two-part scientific naming system giving each species a genus name and a species name, both usually Latin and italicized, with the genus capitalized.
- Dichotomous key
- A tool for identifying organisms using a series of paired either-or choices based on observable characteristics, narrowing to one species.