Lab 4: Mitosis & Meiosis Flashcards
phases of cell cycle
Interphase, PMAT
G1 phase
Growth phase
Cells grow and produce RNA, ribosomes, enzymes
Duplication of organelles and protein synthesis
S phase
-DNA replication occurs
-Each cell new cell produced needs to have same -DNA content as original
-Helical molecule of DNA uncoils and 2 strands separate
-Exposed base pair of old DNA strand pairs with complementary base of new synthesized strand and H bond reforms
G2
-Spindle fiber proteins are made
-Cell prepares for actual division
-May be some additional growth
-May be some accumulation energy reserves and synthesis of enzymes and other proteins
mitosis
division of nucleus that result in genetically identical daughter cells
meiosis
creates gametes for sexual reproduction
cytokinesis
cytoplasm splits to form 2 identical daughter cells
mitosis function
growth, replacement, repair
Meiosis function
ensure we have haploid gametes and introduce genetic variation
2 ways to introduce genetic variation
- crossing over = prophase I
- independent assortment = metaphase I
diploid
characteristic genetic composition of body cells. contains a complete complement of chromosomes (humans = 46, 23 homologous)
haploid
chromosome number characteristic of gametes (sperm + ova), in which only one member of each pair of homologous is present (humans = 23 individual chromosomes)
homologous chromosome
Two chromosomes in a pair – normally one inherited from the mother and one from the father.
tetrad
2 pairs of homologous pairs next to each other, 4 chromatids
chromosome
gene carrying structure
