1 / 20

Chapter 3 The Biological Basis of Life

Chapter 3 The Biological Basis of Life. Key Terms. Nucleus A structure (organelle) found in all eukaryotic cells. The nucleus contains chromosomes (nuclear DNA). Molecules Structures made up of two or more atoms. Molecules can combine with other molecules to form more complex structures.

robertkirby
Download Presentation

Chapter 3 The Biological Basis of Life

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 3 The Biological Basis of Life Key Terms

  2. NucleusA structure (organelle) found in all eukaryotic cells. The nucleus contains chromosomes (nuclear DNA). MoleculesStructures made up of two or more atoms. Molecules can combine with other molecules to form more complex structures.

  3. Deoxyribonucleic acid (DNA)The double-stranded molecule that contains the genetic code. DNA is a main component of chromosomes. Ribonucleic acid (RNA) A single stranded molecule, similar in structure to DNA. The three forms of RNA are essential to protein synthesis.

  4. CytoplasmThe portion of the cell contained within the cell membrane, excluding the nucleus. The cytoplasm consists of a semifluid material and contains numerous structures involved with cell function. ProteinsThree-dimensional molecules that serve a wide variety of functions through their ability to bind to other molecules.

  5. Protein synthesisThe assembly of chains of amino acids into functional protein molecules. The process is directed by DNA. MitochondriaStructures contained within the cytoplasm of eukaryotic cells that convert energy, derived from nutrients, into a form that is used by the cell.

  6. RibosomesStructures composed of a specialized form of RNA and protein. Ribosomes are found in the cell’s cytoplasm and are essential to the manufacture of proteins. Somatic cellsBasically, all the cells in the body except those involved with reproduction.

  7. GametesReproductive cells (eggs and sperm in animals) developed from precursor cells in ovaries and testes. ZygoteA cell formed by the union of an egg and a sperm cell. It contains the full complement of chromosomes (in humans, 46) and has the potential of developing into an entire organism.

  8. NucleotidesBasic units of the DNA molecule, composed of a sugar, a phosphate, and one of four DNA bases. ComplementaryReferring to the fact that DNA bases form base pairs in a precise manner. For example, adenine can bond only to thymine. Thus, these two bases are said to be complementary because one requires the other to form a complete DNA base pair.

  9. EnzymesSpecialized proteins that initiate and direct chemical reactions in the body. ReplicateTo duplicate. The DNA molecule is able to make copies of itself.

  10. HemoglobinA protein molecule that occurs in red blood cells and binds to oxygen molecules. HormonesSubstances (usually proteins) that are produced by specialized cells and that travel to other parts of the body, where they influence chemical reactions and regulate various cellular functions.

  11. Amino acidsSmall molecules that are the components of proteins. Messenger RNA (mRNA) A form of RNA that is assembled on a sequence of DNA bases. It carries the DNA code to the ribosome during protein synthesis.

  12. CodonsThe triplets of messenger RNA bases that correspond to specific amino acids during protein synthesis. Transfer RNA (tRNA) The type of RNA that binds to specific amino acids and transports them to the ribosome during protein synthesis.

  13. GeneSequence of DNA bases that specifies the order of amino acids in an entire protein or, in some cases, a portion of a protein. A gene may be made up of hundreds or thousands of DNA bases. MutationA change in DNA. Technically, mutation refers to changes in DNA bases (specifically called point mutations); also refers to changes in chromosome number and/or structure.

  14. ChromosomesDiscrete structures composed of DNA and protein found only in the nuclei of cells. Visible only under magnification during certain stages of cell division. CentromereThe constricted portion of a chromosome. After replication, the two strands of a double- stranded chromosome are joined at the centromere.

  15. HomologousReferring to members of chromosome pairs. Homologous chromosomes carry genes that govern the same traits. During meiosis, homologous chromosomes pair and exchange segments of DNA. AutosomesAll chromosomes except the sex chromosomes.

  16. Sex chromosomesIn mammals, the X and Y chromosomes. MitosisSimple cell division; the process by which somatic cells divide to produce two identical daughter cells.

  17. MeiosisCell division in specialized cells in ovaries and testes. Meiosis involves two divisions and results in four daughter cells, each containing only half the original number of chromosomes. These cells can develop into gametes. RecombinationThe exchange of DNA between homologous chromosomes during meiosis; also called “crossing over.”

  18. NondisjunctionThe failure of homologous chromosomes or chromosome strands to separate during cell division. Polymerase chain reaction (PCR)A method of producing thousands of copies of a DNA segment using the enzyme DNA polymerase.

  19. Recombinant DNA technologyA process in which genes from the cell of one species are transferred to somatic cells or gametes of another species. CloneAn organism that is genetically identical to another organism. The term may also be used to refer to genetically identical DNA segments and molecules.

  20. Human Genome ProjectAn international effort aimed at sequencing and mapping the entire human genome. GenomeThe entire genetic makeup of an individual or species. In humans, it is estimated that each individual possesses approximately 3 billion DNA nucleotides.

More Related