Download Study Guide CP Cell Division

CP BIO
Ch. 10-11 Cell Division
Study Guide
10.1 Mitosis and Asexual Reproduction
a. Asexual reproduction – one parent cell, genetically identical daughter cells
- for growth, maintenance, repair, reproduction in simple organisms
1. prokaryotes – binary fission
2. eukaryotes – chromosomes organized and distributed equally
b. Rate of division – some tissues often, others rarely; uncontrolled (cancer)
12.2 DNA Molecule – helix, nucleotide, bases (names), base pairs
12.3 DNA Replication – DNA copies: double helix opens, free nucleotides A-T, C-G
- each strand is template  two identical molecules, each has one original
strand and one new strand
10.2 The Process of Cell Division
A) Chromosomes = DNA + histone proteins
a. chromatin – in non-dividing cell
b. in dividing cell: copied DNA condenses into sister chromatids , joined at
centromere
B) The Cell Cycle
a. Interphase G1 S (replication) G2
b. Mitotic Phas mitosis – nucleus divides; cytokinesis - cytoplasms divides
1. prophase – spindle forms, chromatin condenses, nuclear membrane
breaks apart, centrioles move apart
2. metaphase – chromosomes at equator of cell, attach to spindle
3. anaphase – sister chromatids separate & move to opposite poles
4. telophase – two new nuclei form, chromosomes unpack
c. Cytokinesis – cleavage furrow in animal cells; cell plate in plants
C) Cell Differentiation – stem cells
D) Asexual Reproduction – simple animals: budding, regeneration
plants: runners, bulbs, cuttings, grafts
D) Regulating the Cell Cycle – chemical signals, growth factors, contact with nearby
cells, programmed death
E) Cancer – uncontrolled growth, benign tumors, malignant, metastatic, melanoma
11.4 Meiosis and Sexual Reproduction
Two parents – each gives genes  new gene combination in offspring
Two sets of homologous chromosomes – have genes for same traits
A) Diploid and haploid cells
a. Diploid – two sets of chromosomes (2n) –one set from each parent
i. In somatic (body) cells
b. Haploid – one set of chromosomes (n)
i. In sex cells, gametes – egg and sperm
B) Meiosis – two cell divisions, reduces chromosome number by half
a. Interphase - DNA replicates
b. Meiosis I – divides homologous pairs of chromosome
i. Prophase I – pairs match up (synapsis), attach at centromeres
1. Crossing over – homologous chromatids exchange pieces
a. Increases genetic variation
ii. Metaphase I – pairs line up on equator
1. Anaphase I – pairs separate, still two copies- sister chromatids
iii. Telophase I – two haploid nuclei form; cytokinesis
c. Meiosis II – sister chromatids separate; cytokinesis again
 four haploid daughter cells
C) Making Sperm and Egg
a. 2n parent cell  four haploid sperm
b. 2n parent cell  one haploid ovum + 3 polar bodies (die)
D) Fertilization: egg + sperm  zygote n + n  2n
14.2 Problems in Meiosis
A) nondisjunction – pairs or chromatids do not separate correctly
- wrong number in daughter cells
a) trisomy – three copies of one chromosome
- Down’s Syndrome is trisomy #21
b) nondisjunction of sex chromosomes: Klinefelter XXY, Turner XO
B) Chromosome mutations – pieces lost, added, misplaced
a) addition, deletion, inversion, translocation
C) Karyotype – picture of paired, sized chromosomes
a) autosomes – numbers 1-22
b) sex chromosomes – X and Y