Terms : Hide Images
| 6520879871 | crossing over | Process in which homologous chromosomes exchange portions of their chromatids during meiosis. | 0 | |
| 6520879872 | independent assortment | One of Mendel's principles that states that genes for different traits can segregate independently during the formation of gametes | 1 | |
| 6520879873 | segregation | (genetics) the separation of paired alleles during meiosis so that members of each pair of alleles appear in different gametes | 2 | |
| 6520879874 | random fertilization | source of genetic variation caused by the unlimited number of possible sperm & egg combinations | 3 | |
| 6520879875 | homozygous | An organism that has two identical alleles for a trait | 4 | |
| 6520879876 | heterozygous | An organism that has two different alleles for a trait | 5 | |
| 6520879877 | monohybrid cross | A cross between individuals that involves one pair of contrasting traits | 6 | |
| 6520879878 | dihybrid cross | A cross between two individuals, concentrating on two definable traits | 7 | |
| 6520879879 | allele | An alternative form of a gene. | 8 | |
| 6520879880 | gene | A discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA (or RNA, in some viruses). Codes for RNA, polypeptides, and proteins | 9 | |
| 6520879881 | synapsis | Pairing of homologous chromosomes | 10 | |
| 6520879882 | dominant allele | An allele that will determine phenotype if just one is present in the genotype | 11 | |
| 6520879883 | recessive allele | An allele that is masked when a dominant allele is present | 12 | |
| 6520879884 | phenotype | An organism's physical appearance, or visible traits. | 13 | |
| 6520879885 | genotype | An organism's genetic makeup (alleles for a particular gene) | 14 | |
| 6520879886 | test cross | the crossing of an individual of unknown genotype with a homozygous recessive individual to determine the unknown genotype | 15 | |
| 6520879887 | rule of multiplication | A statistical rule stating that the probability of two independent events occuring together is the product of their individual probabilities. | 16 | |
| 6520879888 | rule of addition | A statistical rule stating that the probability of either of two indpendent (and mutually exclusive) events ocuring is the sum of their individual probabilities minus the probability of them both occuring together. | 17 | |
| 6520879889 | complete dominance | A relationship in which one allele is completely dominant over another | 18 | |
| 6520879890 | incomplete dominance | A type of inheritance in which two contrasting alleles contribute to the individual a trait not exactly like either parent; blending inheritance. | 19 | |
| 6520879891 | codominance | Both alleles are equally expressed | 20 | |
| 6520879892 | multiple alleles | three or more forms of a gene that code for a single trait (but each individual only has 2) | 21 | |
| 6520879893 | pedigree | A diagram that shows the occurrence of a genetic trait in several generations of a family | 22 | |
| 6520879894 | cystic fibrosis | an autosomal recessive disorder creating thick sticky mucus which is hard to expel | 23 | |
| 6520879895 | Tay-Sachs | A human genetic disease caused by a recessive allele for a dysfunctional enzyme, leading to accumulation of certain lipids in the brain. Seizures, blindness, and degeneration of motor and mental performance usually become manifest a few months after birth. | 24 | |
| 6520879896 | Sickle Cell | A human genetic disease of red blood cells caused by the substitution of a single amino acid in the hemoglobin protein; creating sickle shaped red blood cells that collect in vessels causing pain and reduced gas exchange | 25 | |
| 6520879897 | lethal dominant allele | having a single dominant allele results in death | 26 | |
| 6520879898 | Huntington's disease | progressive hereditary disorder characterized by uncontrolled movements- changes in cortex & cerebellum | 27 | |
| 6520879899 | sex-linked genes | a gene that is carried on the X or Y chromosome | 28 | |
| 6520879900 | X chromosome | The sex chromosome found in both men and women. Females have two X chromosomes; males have one. An X chromosome from each parent produces a female child. | 29 | |
| 6520879901 | Y chromosome | The sex chromosome found only in males. When paired with an X chromosome from the mother, it produces a male child | 30 | |
| 6520879902 | Duchenne muscular dystrophy | A human genetic disease caused by a sex-linked recessive allele; characterized by progressive weakening and a loss of muscle tissue. | 31 | |
| 6520879903 | Hemophilia | A sex-linked hereditary disease where blood does not coagulate to stop bleeding | 32 | |
| 6520879904 | X-inactivation | a process by which one of the two copies of the X chromosome present in female mammals is randomly inactivated creating a Barr body | 33 | |
| 6520879905 | Barr Body | The inactivated X chromosome | 34 | |
| 6520879906 | Genetic recombination | the regrouping of genes in an offspring that results in a genetic makeup that is different from that of the parents | 35 | |
| 6520879907 | linkage map | A genetic map based on the frequencies of recombination between markers during crossing over of homologous chromosomes. | 36 | |
| 6520879908 | map unit | in chromosome mapping, an increment of 1 percent in the frequency of crossing-over | 37 | |
| 6520879909 | nondisjunction | Error in meiosis in which homologous chromosomes fail to separate. | 38 | |
| 6520879910 | aneuploidy | A chromosomal aberration in which one or more chromosomes are present in extra copies or are deficient in number. | 39 | |
| 6520879911 | polyploidy | Condition in which an organism has extra full sets of chromosomes | 40 | |
| 6520879912 | trisomy | 3 copies of a chromosome | 41 | |
| 6520879913 | monosomy | Chromosomal abnormality consisting of the absence of one chromosome from the normal diploid number | 42 | |
| 6520879914 | mutation | an event that changes the nucleotide sequence in a gene, creating a novel sequence which may have no function or a new function | 43 | |
| 6520879915 | point mutation | Gene mutation involving changes in one or a few nucleotides | 44 | |
| 6520879916 | deletion | (1) A deficiency in a chromosome resulting from the loss of a fragment through breakage. (2) A mutational loss of one or more nucleotide pairs from a gene. | 45 | |
| 6520879917 | duplication | An aberration in chromosome structure due to fusion with a fragment from a homologous chromosome, such that a portion of a chromosome is duplicated. | 46 | |
| 6520879918 | inversion | (genetics) a kind of mutation in which the order of the genes in a section of a chromosome is reversed | 47 | |
| 6520879919 | translocation | Change to a chromosome in which a fragment of one chromosome attaches to a nonhomologous chromosome | 48 | |
| 6520879921 | Down Syndrome | A condition of retardation and associated physical disorders caused by an extra copy of chromosome 21. | 49 | |
| 6520879922 | Klinefelter syndrome | A chromosomal disorder in which males have an extra X chromosome, making them XXY instead of XY. | 50 | |
| 6520879923 | Turner Syndrome | a monosomic condition where a female has only 1 sex chromosome- the only known viable monosomy in humans | 51 | |
| 6520879924 | true breeding | If an organism has a certain characteristic that is always passed on to its offspring, we say that this organism bred true with respect to that characteristic. | 52 | |
| 6520879925 | linked genes | Genes located close enough together on a chromosome that they tend to be inherited together. | 53 | |
| 6520879926 | carrier | A person whose genotype includes a gene that is not expressed in the phenotype. | 54 |
