Dr. Westholm's Human Biology and Heredity class at The College of St. Scholastica
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| 1111358458 | diploid | - 23 pairs, 46 total | 1 | |
| 1111358459 | haploid | - 1 copy of each duplicated chromosome | 2 | |
| 1111358460 | autosome | - two of each chromosome | 3 | |
| 1111358461 | sex chromosome | - on the 23rd chromosome | 4 | |
| 1111358462 | homologous chromosome | - pairs of corresponding chromosomes - contains same genes (not necessarily same sequence) | 5 | |
| 1111358463 | how is DNA organized? | - in structures called chromosomes | 6 | |
| 1111358464 | what structures are included in the organization of DNA? | - proteins | 7 | |
| 1111358465 | interphase | - longest stage - G1, S, and G2 phases | 8 | |
| 1111358466 | G1 phase | - cell growth | 9 | |
| 1111358467 | S phase | - DNA copied and its chromosomes are duplicated | 10 | |
| 1111358468 | G2 phase | - preparation for mitosis | 11 | |
| 1111358469 | Mitosis | - chromosomes are sorted into two sets and the cytoplasm divides | 12 | |
| 1111358470 | mitosis: prophase | - chromosomes duplicated - spindle fibers connect to centromere | 13 | |
| 1111358471 | cytokinesis | - division of cytoplasm of a dividing cell | 14 | |
| 1111358472 | how does cytokinesis occur? | - former spindle equator forms a ring of microfilaments attached to the plasma membrane and it contracts | 15 | |
| 1111358473 | spermatogenesis | - formation of sperm through meiosis | 16 | |
| 1111358474 | oogenesis | - formation of eggs (oogonium) through meiosis | 17 | |
| 1111358475 | compare and contrast mitosis and meiosis | - meiosis is the first step in the formation of gametes (sperm and eggs) for sexual reproduction - mitosis is the splitting of diploid germ cells to haploid nuclei (somatic cells) | 18 | |
| 1111358476 | crossing over | - occurs in meiosis - homologous chromosomes exchange corresponding segments | 19 | |
| 1111358477 | what is the result of crossing over? | - variations in inherited traits | 20 | |
| 1111358478 | the consequence of germ cells that performed mitosis instead of meiosis? | ... | 21 | |
| 1111358479 | gene | - humans have about 21,500 - chemical instructions for building proteins | 22 | |
| 1111358480 | allele | - each version of a gene | 23 | |
| 1111358481 | gene locus | - specific location on a chromosome to find a gene | 24 | |
| 1111358482 | dominent | - presence of a dominant trait will mask recessive - example: widow's peak | 25 | |
| 1111358483 | recessive | - need two copies of a recessive allele for expression of trait - hitchhiker's thumb | 26 | |
| 1111358484 | homozygous | - identical alleles | 27 | |
| 1111358485 | heterozygous | - different alleles | 28 | |
| 1111358486 | genotype | - inherited alleles - example: AA, Aa, aa | 29 | |
| 1111358487 | phenotype | - observable functional or physical traits - height, eye color, etc. | 30 | |
| 1111358488 | intro to genetics #2 | look on study guide | 31 | |
| 1111358489 | independent assortment | - occurs during meiosis - a given chromosome and its genes move randomly into gametes | 32 | |
| 1111358490 | intro to genetics #4 | look on study guide | 33 | |
| 1111358491 | co-dominence | - heterozygous for a trait, but both alleles are expressed | 34 | |
| 1111358492 | how does co-dominence apply to blood typing? | - alleles for blood type determine presence or absence of polysaccharides on surface of red blood cells | 35 | |
| 1111358493 | polygenic traits | - combined expression of several genes - examples: height, disease susceptibility, hair color, eye color | 36 | |
| 1111358494 | continuous variation | - populations show a range of continuous differences - most evident in traits that can be measured (ex. height) | 37 | |
| 1111358495 | three ways the environment can influence gene expression | - medicines, smoking, drinking - stress - diet | 38 | |
| 1111358496 | linkage | - is the distance between them is short - less likely to be separated during crossing over - tend to stay together/inherited together | 39 | |
| 1111358497 | what orientation of genes are most likely to be linked? | - close together | 40 | |
| 1111358498 | compare the X and Y chromosomes with respect to number of genes | - X = 2000+ - Y = few | 41 | |
| 1111358499 | what does the SRY gene do on the y-chromosome? | - stimulate production of testosterone | 42 | |
| 1111358500 | why does the father determine the sex of a baby? | - contains the Y chromosome (boy) and another X chromosome (girl) | 43 | |
| 1111358501 | x-inactivation | - most of one of a female's X chromosome turned off soon after first division of zygote - condenses into a Barr body - mosaic expression of maternal and paternal chromosomes | 44 | |
| 1111358502 | what is the consequence of x-inactivation | - incontinentia pigmenti - darker patches of skin color are visible in tissue where the mutated X chromosomes active | 45 | |
| 1111358503 | x-linked genetic disorders nearly exclusively affect males? | - males have 1 X chromosome - don't have another allele to make up for faulty copy | 46 | |
| 1111358504 | chromosomes #6 | look on study guide | 47 | |
| 1111358505 | two examples of x-linked disorders and their basic symptoms | - hemophilia A - most common form - mutation in the gene for the clotting protein factor VIII - caused by inbreeding - duchene muscular dystrophy - mutated form of muscle supposed protein - muscles degenerate, lose ability to walk - usually die by age 30 from cardiac or reparatory failure | 48 | |
| 1111358506 | chromosomes #8 | look on study guide | 49 | |
| 1111358507 | cystic fibrosis | - fatal usually before age 30 - thickened mucus: clogs airways - infections - treatment: physiotherapy and antibiotics | 50 | |
| 1111358508 | how is cystic fibrosis inherited? | - faulty CFTR gene - inherited from both parents | 51 | |
| 1111358509 | huntington disease | - progressive degeneration of nervous system - symptoms appear after age 30 - fatal - mutation on chromosome 4 | 52 | |
| 1111358510 | how is huntington disease inherited | - need one copy of faulty gene to have disorder (autosomal genetic disorder) | 53 | |
| 1111358511 | what is sickle cell anemia? | - homozygous recessive - one amino acid substitution in hemoglobin - val instead of glu - pleiotropic effects - relatively common for a recessive genetic disorder - heterozygous - confers resistance to malaria | 54 | |
| 1111358512 | why had the recessive allele persisted in the human population? | ... | 55 | |
| 1111358513 | chromosomes # 12 | look on study guide | 56 | |
| 1111358514 | non-disjuction | - one or more pairs of chromosomes fail to separate during cell division - increases with a woman's age - if such a gamete is fertilized: trisomy or monosomy | 57 | |
| 1111358515 | one example of a genetic disorder resulting from non-disjunction | - down's syndrome - defect of chromosome 21 (trisomy 21) - mental retardation, abnormal skeletal development, motor functions delayed, and weaker muscles | 58 | |
| 1114112345 | mitosis: metaphase | - chromosomes align at the equator | 59 | |
| 1114112346 | mitosis: anaphase | - sister chromatids separate and move to poles | 60 | |
| 1114112347 | mitosis: telephase | - two diploid nuclei form | 61 |
