Biology I (Cummulative)
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197 terms
Terms | Definitions |
|---|---|
 chromosome | a collection of DNA and protein |
| gene | a sequence of DNA on a chromosome containing a specific characteristic; the code for making one protein |
| alleles | different forms of the same gene, occupying the same place on a chromosome and affecting the same characteristic but in different ways |
| haploid | a nucleus containing a single set of unpaired, "n" chromosomes (such as gamete cells) |
| diploid | a nucleus with two sets of paired, "2n" chromosomes, where half comes from the mother and half from the father |
| genotype | the alleles possesed by an organism |
| phenotype | the characteristics that an organism has as a result of its genotype |
| homozygous | having two identical alleles of a gene |
| heterozygous | having two different alleles of a gene |
| dominant | the kind of allele with the same effect on the phenotype whether in the homozygous or heterozygous state |
| recessive | the kind of allele that only has a phenotypical effect when present in a homozygous state |
| codominant | the kind of allele with a partial phenotypical effect when present in heterozygotes, but a greater one in homozygotes |
| mutation | a spontaneous change in the genetic material of a cell |
| locus | the particular position of a gene on homologous chromosomes |
| carrier | an individual that has a recessive allele of a gene not expressed phenotypically |
| interphase | the stage where a cell grows and replicates its DNA and centrioles |
| prophase | the first stage of mitosis, where the chromatin condenses into chromosomes, the centrioles separate, a spindle begins to form, and the nuclear envelope breaks down |
| metaphase | the second stage of mitosis, where the chromosomes line up across the center of the cell and each is connected to a spindle fiber at its centromere |
| anaphase | the third stage of mitosis, where the sister chromatids separate into individual chromosomes and are pulled apart |
| telophase | the last stage of mitosis, where the chromosomes gather at opposite ends of the cell and lose their distinct shape as two new nuclear envelopes begin to form |
| cytokinesis | the stage where the cytoplasm pinches in half |
| mitosis | division of the cell nucleus |
| chromatids | the two identical strands into which a chromosome splits during mitosis |
| centromeres | the condensed regions of each chromosome that appear during mitosis |
| meiosis | cell division that produces reproductive cells in sexually reproducing organisms |
| prophase I | the first stage of meiosis I where homologous chromosomes shorten, thicken, and pair up (undergoing crossing over) |
| metaphase I | the second stage of meiosis I where crossing over is complete and homologous chromosome pairs line up across the center of the cell |
| anaphase I | the third stage of meiosis I where spindle fibers separate homologous chromosomes and pull them towards opposite poles of the spindle |
| telophase I | the last stage of meiosis I where haploid cells of chromosomes are at each end of the cell |
| prophase II | the first stage of meiosis II where centrioles move to opposite ends of the cell and new spindle fibers appear |
| metaphase II | the second stage of meiosis II where chromosomes line up separately around the equator of the spindle |
| anaphase II | the third stage of meiosis II where chromatids are separated and spindle fibers pull them to opposite ends of the cell |
| telophase II | the last stage of meiosis II where there are four haploid daughter cells formed, and chromosomes uncoil and lengthen |
| Cytosine | DNA/RNA pyrimidine base that bonds with guanine |
| Thymine | DNA pyramidine base that bonds with adenine |
| Guanine | DNA/RNA purine base that bonds with cytosine |
| Adenine | DNA/RNA purine base that bonds with thymine |
| Uracil | RNA pyramidine base that bonds with adenine |
| deoxyribonucleic acid | DNA, a double-stranded nucleic acid that contains the sugar deoxyribose |
| ribonucleic acid | RNA, a single-stranded nucleic acid that contains the sugar ribose |
| nitrogenous base | an organic base that contains nitrogen, such as a purine or pyrimidine; a subunit of a nucleotide in DNA and RNA |
| pentose sugar | a five-carbon sugar molecule found in nucleic acids |
| covalent bonds | the strong bonds that hold the backbone of DNA together |
| hydrogen bonds | the weak bonds that join nitrogenous bases together |
| DNA helicase | an enzyme that "unzips" a double-helix of DNA |
| DNA polymerase | an enzyme that makes the covalent bonds between the nucleotides of new DNA strands and also helps replace RNA primers with DNA |
| RNA polymerase | an enzyme similar to DNA polymerase that binds to DNA and separates the DNA strands during transcription |
| RNA primase | an enzyme that creates an RNA primer for initiation of DNA replication |
| Okazaki fragments | short fragments of DNA that are a result of the synthesis of the lagging strand during DNA replication. |
| nucleus | the membrane-bound area of the cell where DNA is stored and both replication and transcription happen |
| mRNA | messenger ribonucleic acid that is produced by RNA polymerase and carries DNA protein coding instruction to the rest of the cell |
| tRNA | transfer ribonucleic acid that transfers each amino acid as specified by coded messages in mRNA |
| rRNA | ribosomal ribonucleic acid |
| polypeptide | a polymer (chain) of many amino acids linked together by peptide bonds |
| ribosome | small particle in the cell on which proteins are assembled; made of RNA and protein |
| nucleotide | the smallest unit of DNA |
| phosphate group | chemical group consisting of a phosphorus atom bonded to four oxygen atoms; important in energy transfer. |
| codon | a specific sequence of three adjacent bases on a strand of DNA or RNA that provides genetic code information for a particular amino acid |
| anticodon | group of three bases on a tRNA molecule that are complementary to an mRNA codon |
| ribose | a pentose sugar important as a component of ribonucleic acid |
| peptide bond | the primary linkage of all protein structures |
| nucleosome | a structure consisting of eight histones with DNA wrapped twice around each |
| histone | the protein found in chromatin |
| coil | a thick fiber of nucleosomes packed together |
| supercoil | the coiling of coils of nucleosomes |
| chromosome | threadlike structure within the nucleus containing the genetic information that is passed from one generation of cells to the next |
| RNA primer | short segment of RNA used to initiate synthesis of a new strand of DNA during replication |
| DNA ligase | an enzyme that eventually joins the sugar-phosphate backbones of the Okazaki fragments |
| purines | adenine and guanine |
| pyramidines | thymine and cytosine |
| transcription | copying part of the nucleotide sequence of DNA into a complementary RNA sequence |
| translation | decoding of a mRNA message into a polypeptide chain |
| replication | the copying process undergone by DNA before a cell divides |
| introns | sequences of nucleotides not involved in coding for proteins |
| exons | sequences of nucleotides involved in coding for proteins |
| chromatin | DNA tightly coiled around proteins called histones; The substance that makes up eukaryotic chromosomes |
| promoters | regions of DNA that indicate to RNA polymerase where to bond |
| carbohydrate | chemical identification card attatched to the outside of a plasma membrane |
| glycoprotein | protein with carbohydrates attatched |
| glycolipid | lipid with carbohydrates attatched |
| hydrophilic head | the phosphate, water-loving part of a phospholipid |
| hydrophobic tail | the fatty acid, water-fearing part of a phospholipid |
| phospholipid bilayer | the structure of a plasma membrane: hydrophilic heads and hydrophobic tails forming a "sandwich" (bilayer) |
| microfilaments | the parts of the cytoskeleton that keep the plasma membrane in place |
| peripheral protein | protein lying only on one side of the plasma membrane |
| cholesterol | sterol in the plasma membrane that makes the membrane firmer |
| integral protein | protein embedded within the phospholipid bilayer |
| distilled | purified or concentrated |
| diffusion | movement of molecules from high to low concentration |
| semi-permeable | partially permeable |
| osmosis | water molecule diffusion across a semi-permeable membrane |
| active transport | movement of molecules from low to high concentration (against natural movement) |
| ATP | molecule used for energy in active transport |
| hypo- | prefix meaning "less than" |
| hyper- | prefix meaning "more than" |
| iso- | prefix meaning "same as"/"equal to" |
| -tonic | suffix meaning "solution" |
| pinocytosis | type of endocytosis that means "cell drinking" |
| facilitated diffusion | movement of substances from high to low concentrations, using carrier proteins |
| phagocytosis | type of endocytosis that means "cell eating" |
| isotonic | solution with equal concentration to the cell it surrounds |
| hypotonic | solution with lower concentration than the cell it surrounds |
| hypertonic | solution with higher concentration than the cell it surrounds |
| passive transport | movement of molecules across a plasma membrane without any energy used by cell |
| concentration gradient | the difference between two concentrations |
| endocytosis | taking material into the cell by means of an infolding of the plasma membrane (forms vacuoles within cytoplasm) |
| lyse | to burst |
| turgor | water pressure in plant cells, built up due to osmosis |
| exocytosis | removing material of cell vacuoles by means of vacuoles fusing with the plasma membrane |
| contractile vacuoles | organelles that pump out excess water |
| carrier protein | a special molecule that moves certain larger molecules through the membrane |
| cytolysis | the bursting of cells due to osmosis |
| Fluid Mosaic Model | the current model of membrane structure |
| Brownian motion | random movement of molecules |
| plasmolysis | the shrinking of plant cells due to osmosis |
| equilibrium | equal concentrations between cell and solute |
| homeostasis | process by which organisms maintain a relatively stable internal environment |
| plasma membrane | thin, flexible barrier that all cells are surrounded by |
| cell wall | strong supporting layer around plant cells |
| molecular transport | transport through energy-requiring pumps that are used for active transport |
| independent variable | in an experiment, the variable that you are changing |
| dependent variable | in an experiment, the variable that you are measuring |
| control variables | in an experiment, the variables that must stay the same across different groups of scenarios |
| observation | use of the senses to gather or notice information |
| hypothesis | a possible, testable explanation of an observation |
| variables | factors in an experiment that can be changed or measured |
| experiment | the controlled testing of a hypothesis |
| conclusion | the support or rejection of a hypothesis after an experiment |
| scientific theory | a broad and comprehensive statement of what is thought to be true in science |
| animals | living organisms that cannot make their own food |
| vertebrates | animals that have a backbone |
| fish | vertebrates with overlapping scales, fins, gills, and cold blood, e.g. trouts |
| amphibians | vertebrates with smooth, moist skin, and four limbs, e.g. frogs |
| reptiles | vertebrates with non-overlapping scales, and four limbs, e.g. lizards |
| birds | vertebrates with feathers, wings, a beak, and scales on their legs, e.g. eagles |
| mammals | vertebrates with fur, four limbs, mammary glands, and external ears, e.g. humans |
| invertebrates | animals that do not have a backbone |
| annelids | invertebrates with a segmented body and bristles for movement, e.g. earthworms |
| nematodes | invertebrates with a flattened body and a mouth, but no anus, e.g. tapeworms |
| molluscs | invertebrates with a soft body, a muscular foot, and tentacles, e.g. snails |
| arthropods | invertebrates with a segmented body and a hard, waterproof exoskeleton |
| crustaceans | arthropods with two pairs of antennae, more than four pairs of legs, and compound eyes, e.g. crabs |
| insects | arthropods with three body parts, three pairs of legs, compound eyes, and typically two pairs of wings, e.g. honeybees |
| arachnids | arthropods with two body parts, four pairs of legs, and eight eyes, e.g. spiders |
| myriapods | arthropods with jawed heads, legs on each body segment, and one pair of antennae, e.g. millipedes |
| plants | living organisms that can make their own food |
| monocotyledons | plants with narrow leaves, parallel veins, and flower parts in multiples of three |
| dicotyledons | plants with broad leaves, branching veins or midrib, and flower parts in multiples of four or five |
| fungi | living organisms that are made up of thread-like cells cells, produce spores, and fed on dead or decaying material |
| bacteria | prokaryotes that are made up of one cell, have no nucleus or membrane-bound organelles, and have circular DNA |
| Cell Theory | the theory that all living things are made out of cells, the basic units of life, and that all new cells are made from existing ones |
| eukaryotes | cells that contain nuclei |
| prokaryotes | cells that don't contain nuclei |
| organelles | tiny structures within cells |
| cytoplasm | the material between the cell membrane and the nucleus |
| nucleus | the DNA-containing cell organelle that is enclosed by the nuclear envelope |
| nuclear envelope | the two membranes that separate the nucleus from cytoplasm |
| nuclear pores | structures in the nuclear envelope that allow passage of certain materials |
| chromatin | DNA bound to protein within the nucleus; the origin of chromosomes |
| chromosomes | threadlike genetic structures that originate from condensed chromatin |
| nucleolus | organelle where ribosomes are made, synthesized and partially assembled, located in the nucleus |
| ribosomes | the sites of protein synthesis within a cell, made up of protein and RNA |
| endoplasmic reticulum | the organelle, made up of cisternae, that produces lipids for the cell membrane and exports proteins and other materials |
| cisternae | the system of flattened, membrane-bounded sacs that make up the endoplasmic reticulum |
| rough ER | endoplasmic reticulum with ribosomes on its surface |
| smooth ER | endoplasmic reticulum without ribosomes on its surface |
| golgi apparatus | the organelle, made up of cisternae, that modifies, sorts, and packages proteins and also makes lysosomes |
| lysosomes | the organelles that are responsible for breakdown of structures and molecules |
| vacuoles | the organelles that function as storage and sometimes, within plant cells, replace the role of lysosomes |
| mitochondria | the organelles that turn chemical energy into usable compounds |
| chloroplasts | the organelles that turn sunlight energy into chemical energy |
| chlorophyll | the chemical that chloroplasts consist of |
| cytoskeleton | the network of protein filaments that support the cell and allow for movement |
| centrioles | the tiny organelles that lie near the nucleus and play a role in cell division |
| microbodies | the spherical organelles that contain catalase and break down hydrogen peroxide |
| plasma membrane | the trilaminar, partially permeable barrier that controls exchange between a cell and its environment |
| cell wall | the strong, supporting layer of cells that lies beyond the cell membrane |
| middle lamella | the thin layer of pectic substances that cements neighboring cells together |
| plasmodesma | the fine cytoplasmic thread that allows for symplast to be formed between neighboring cells, hence enabling substance exchange |
| microfilaments | fine, threadlike proteins found in the cell's cytoskeleton |
| microtubules | hollow tubes of protein found in the cell's cytoskeleton |
| cilia | short, hair-like structures made of microtubules that enable movement of cells or movement of materials outside a cell |
| flagella | whiplike tails found in one-celled organisms to aid in movement, made up of microtubules |
| movement | change in location or position; process carried out by all living things |
| respiration | breaking down food molecules to release energy; process carried out by all living things |
| sensitivity | the ability to detect and respond to stimuli; process carried out by all living things |
| growth | increase in size and dry mass, often as a result of cell division; process carried out by all living things |
| reproduction | production, sexual or asexual of more organisms; process carried out by all living things |
| excretion | getting rid of waste from chemical reactions; process carried out by all living things |
| nutrition | getting (or making) and using food; process carried out by all living things |
| kingdom | highest taxonomic rank (above phylum) |
| phylum | second highest taxonomic rank (below kingdom, above class) |
| class | third highest taxonomic rank (below phylum, above order) |
| order | "middle" taxonomic rank (below class, above family) |
| family | third lowest taxonomic rank (below order, above genus) |
| genus | second lowest taxonomic rank (below family, above species) |
| species | lowest taxonomic rank (below genus) |
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