Syllabus BIO 101-011
SYLLABUS BIO 101-004
OAKTON COMMUNITY COLLEGE111004
1) Chromatin – strands of DNA in nucleus during Interphase
2) Sister chromatids = two half’s of a chromosome
3) Chromatids = 2x # of chromosomes / one half of a replicated chromosome
4) Chromosome = coiled up DNA that passes genes on the DNA to daughter cells when the cell divides
- most visible during mitosis/meiosis
5) Centromere – middle of a sister chromatid
i. Divides at onset of Anaphase in Mitosis and Anaphase II in Meiosis
6) Spindle fibers – what pull chromosomes apart during cell division
7) Cleavage furrow – bit of cleavage that animal cells make when dividing
8) Diploid (2n) – cell containing 2 homologous sets of chromosomes, one from each parent
i. Reproduces sexually
ii. What all cells have except egg + sperm
iii. Double the haploid
9) Haploid (n) – half the Diploid # of genes, is the egg + sperm cells
10) Dyad = 2 chromatid
11) Tetrad = 4 chromatid (Haploid #)
12) Crossing over – when chromosomes exchange segments to rearrange genetic information during Prophase I of Meiosis
13) Homologous chromosomes – 2 chromosomes making up matched pair in a diploid cell
- Same length, centromere position, and staining pattern
- Possess genes for same traits at corresponding loci
- 1 from father, 1 from mother
14) Autosomes – chromosome not involved in determining an organism’s sex
15) Sex chromosomes – determine organism’s sex
16) Gametes – reproductive cells (egg/sperm)
17) Chiasmata – microscopically visible site where crossing over has occurred between chromatids of homologous structures during Prophase I of Meiosis
18) Somatic cell – typical body cell
19) Karyotype – micrographs of the metaphase chromosomes of a cell (nucleus)
20) Karyokinesis – division of nucleus
21) Gametogenesis – creation of gametes within gonads
22) OOgenesis – creation of mature egg cells
23) Spermatogenesis – creation of sperm cells
24) Polar bodies – byproducts of primary/secondary oocyte at each point of meiotic division in oogenesis (not in spermatogenesis)
25) Girls are born with their eggs already made in Prophase I; puberty comes during Metaphase II
26) Prophase is longest phase of Meiosis
27) Klinefelters – XXY (when a male has an extra X chromosome)
28) Metafemale – XXX (when a female has an extra X chromosome)
29) Turners Syndrome – X0 (45 chromosomes in female, where they lack another X chromosome)
30) Not viable – Y0
31) Mitosis – growth/repair
- One diploid parent cell divides to form 2 genetically identical daughter cells
- Used for asexual reproduction in unicellular organisms
- Cell cycle = 90% Interphase, 10% Mitotic phase
- Interphase
i. G1 – cell grows + carries out normal metabolism; organelles duplicate
ii. S – DNA replication + chromosome duplication
iii. G2 – construction of spindle apparatus; chromosomes condense; cell continues growing
- Prophase – nuclear envelope + nucleoli disappear
i. Spindle fibers begin to form
ii. Chromosomes begin to supercoil and are visible for 1st time
iii. Centrosome head to poles of cell
- Metaphase
i. Spindle fibers fully formed
- Attached to all of the kinetochores
ii. Centrosome are on polar sides of cell
- Anaphase
i. Sister chromatids pulled apart at centromere by spindle fibers retracting, resulting in 1 member of each sister chromatid pair moving into a new cell
- Telophase
i. 2 daughter cells have clear body
ii. Spindle fibers start disappearing
iii. Nucleoli reappears
iv. Chromosomes uncoil
- Cytokinesis – division of the cell/cytoplasm to form 2 separate daughter cells
i. Cleavage furrow forms
32) Meiosis – egg/sperm (sexual cell division)
- One parent cell (2n) divides to form 4 haploid daughter cells which are then processed into gametes
- Meiosis I – homologous chromosomes separate
i. Interphase I – chromosomes duplicates à each chromosome has 2 genetically identical sister chromatids
ii. Prophase I – crossing over occurs à tetrad forms as a result of synapsis
iii. Metaphase I – spindle microtubules attached to a kinetochore
iv. Anaphase I – sister chromatids remain attached à homologous chromosomes separate toward 2 poles of cell
v. Telophase I + Cytokenesis – cleavage furrow forms
- Meiosis II – sister chromatids separate during Anaphase II