chapter twelve Flashcards
what does cell division result in?
2 daughter cells
what is the purpose of cellular division?
reproduction, growth, repair
unicellular cell division
clones
- ex. amoeba
multicellular cell division
- reproduction (some organisms that don’t form gametes - asexual/sexual)
- growing (embryo, new blood cells)
- differentiating (which genes where expressed when)
- repair
genome
a cell’s DNA/genetic information
chromatin
entire complex of DNA and proteins that make up chromosomes
what is the purpose of protein in DNA?
combats negative charge of nucleotides
chromosomes
structures composed of chromatin
- eukaryotic (long DNA molecule w/ many proteins)
- after S phase, they have sister chromatids
sister chromatids
joined copies of the original chromosome
- attached by cohesions
centromere
region made up of repetitive sequences in the chromosomal dNA where the chromatid is attached most closely to a sister chromatid
- where kinetochores bind
homologous chromosomes
pair of chromosomes that have same order of genes but with some variation
somatic cells
diploid
- 2n number of chromosomes
gametes
haploid
- n number of chromosomes
mitosis
division of genetic material in the nucleus
cytokinesis
division of the cytoplasm
- follows mitosis
what do the cell division cycles consist of?
alternating M ( mitotic - mitosis/cytokinesis) phase with interphase (90% of cycle)