ЦТ Biology flashcards
ЦТ Biology · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Levels of organization
- The hierarchical sequence from molecular and cellular through tissue, organ, organism, population-species, biogeocenotic, to biospheric levels, each with emergent properties not present at lower levels.
- Scientific method
- A procedure of observation, hypothesis formation, controlled experiment, data analysis, and conclusion, in which the experimental group differs from the control by one variable.
- Cell membrane
- A phospholipid bilayer with embedded proteins that selectively controls the exchange of substances between the cell and its environment, providing selective permeability and receptor function.
- Mitochondrion
- A double-membrane organelle with cristae containing its own DNA and ribosomes; it synthesizes ATP by oxidative phosphorylation during aerobic respiration.
- Ribosome
- A non-membrane organelle consisting of rRNA and proteins that reads mRNA codons and catalyzes peptide bond formation during protein synthesis.
- Chloroplast
- A double-membrane organelle containing thylakoid grana and stroma with chlorophyll; it carries out the light reactions and the Calvin cycle of photosynthesis.
- Glycolysis
- The anaerobic cytoplasmic breakdown of one glucose molecule into two pyruvate molecules, yielding a net gain of two ATP and two NADH.
- Light reactions
- Thylakoid reactions in which water is split by light energy, releasing oxygen and producing ATP and NADPH for use in the Calvin cycle.
- Calvin cycle
- The stroma reactions of photosynthesis in which CO2 is fixed by RuBisCO and reduced using ATP and NADPH to form glucose.
- Chemosynthesis
- The synthesis of organic compounds from CO2 using energy released by oxidation of inorganic substances such as ammonia or hydrogen sulfide by bacteria.
- Mitosis
- Nuclear division producing two genetically identical diploid daughter cells, proceeding through prophase, metaphase, anaphase, and telophase with cytokinesis.
- Meiosis
- Two successive divisions producing four haploid cells, with crossing over in prophase I and independent chromosome assortment in metaphase I.
- Gastrulation
- The embryonic stage in which the blastula is transformed into a gastrula with ectoderm, endoderm, and mesoderm, the three germ layers that form organs.
- Double fertilization
- In angiosperms, one sperm fuses with the egg to form a diploid zygote, while the other fuses with two polar nuclei to form triploid endosperm.
- Mendel's first law
- Crossing homozygous dominant and recessive parents yields a uniform first filial generation with the dominant phenotype, as alleles segregate without blending.
- Law of independent assortment
- Genes located on different chromosomes are inherited independently, producing a 9:3:3:1 phenotypic ratio in a dihybrid cross of heterozygotes.
- Test cross
- A cross of an individual showing a dominant phenotype with a recessive homozygote, used to determine whether the dominant individual is homozygous or heterozygous.
- Sex-linked inheritance
- Inheritance of genes located on the X chromosome, causing recessive disorders such as hemophilia and color blindness to appear more frequently in males.
- Transcription
- The synthesis of messenger RNA from a DNA template by RNA polymerase in the nucleus, proceeding in the 5' to 3' direction.
- Translation
- The synthesis of a polypeptide on a ribosome, in which mRNA codons pair with tRNA anticodons and amino acids are joined in sequence.
- Restriction enzyme
- An enzyme that recognizes and cuts DNA at a specific palindromic nucleotide sequence, producing fragments used in genetic engineering.
- Polymerase chain reaction
- An in vitro method that amplifies a DNA segment through repeated cycles of denaturation, primer annealing, and extension by a thermostable DNA polymerase.
- Lichens
- Symbiotic associations of a fungus and an alga or cyanobacterium that form a thallus and serve as sensitive indicators of air pollution.
- Fungi
- Heterotrophic eukaryotes with chitin cell walls and filamentous hyphae forming a mycelium, reproducing by spores and absorbing nutrients from the environment.
- Monocotyledons
- A class of angiosperms whose seeds contain one cotyledon and whose leaves have parallel venation and whose floral parts are usually in threes.
- Arthropods
- A phylum of segmented invertebrates with a chitin exoskeleton and jointed appendages, including insects, arachnids, and crustaceans.
- Chordates
- A phylum of animals possessing, at some developmental stage, a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail.
- Nephron
- The functional unit of the kidney that filters blood in the glomerulus, reabsorbs useful substances, and secretes wastes to form urine.
- Conditioned reflex
- An acquired response formed by repeated pairing of a neutral stimulus with an unconditioned stimulus, mediated by temporary connections in the cerebral cortex.
- Natural selection
- The differential survival and reproduction of individuals with heritable traits better suited to their environment, leading to adaptation and evolutionary change.
- Hardy-Weinberg equilibrium
- The state in which allele and genotype frequencies (p² + 2pq + q² = 1) remain constant across generations in a large, randomly mating population without selection, mutation, or migration.
- Biogeocenosis
- A self-regulating community of interacting organisms and their abiotic environment in a defined area, characterized by a specific species composition and energy flow.