cell cycle
Outline the role of cyclins in the cell cycle.
Cyclins regulate progression through the cell cycle by activating cyclin-dependent kinases.
State the purpose of mitosis.
To produce genetically identical cells for growth and repair.
Define homologous chromosomes.
Chromosome pairs with the same genes but possibly different alleles.
Define diploid.
Cells with two sets of chromosomes.
Define nondisjunction.
Failure of chromosomes to separate properly.
Distinguish between G1 and G2 phases.
G1 involves growth and normal metabolism; G2 prepares the cell for mitosis.
Identify the stage: chromosomes aligned at the equator.
Metaphase
Explain crossing over.
Exchange of genetic material between homologous chromosomes in prophase I.
State when DNA replication occurs.
S phase
State one consequence of nondisjunction.
Abnormal chromosome number
Explain the importance of checkpoints.
They ensure DNA is correctly replicated and conditions are suitable before progression.
Explain how chromosome movement occurs during anaphase.
Spindle fibers shorten, pulling sister chromatids to opposite poles.
Describe independent assortment.
Random orientation of homologous pairs during metaphase I.
Explain the role of the centromere
It holds chromatids together and attaches to spindle fibers.
Explain how nondisjunction occurs in meiosis I.
Homologous chromosomes fail to separate.
Predict what would happen if the G1 checkpoint fails.
Damaged DNA may be replicated, increasing mutation risk.
Compare cytokinesis in plant vs animal cells.
Plants form a cell plate; animals form a cleavage furrow.
Explain how meiosis increases genetic diversity.
Through crossing over and independent assortment.
Distinguish between chromatin and chromosomes.
Chromatin is uncondensed DNA; chromosomes are condensed structures.
Predict the chromosomal outcome of nondisjunction.
Gametes with extra or missing chromosomes.
Explain how external factors can influence the cell cycle.
Nutrients, growth factors, and signals can either promote or inhibit division.
Explain why mitosis maintains genetic stability.
DNA is replicated accurately and equally distributed.
Predict the effect of no crossing over.
Reduced genetic variation in gametes.
Explain why DNA condensation is necessary during division.
To prevent tangling and ensure accurate separation.
Evaluate the impact of chromosomal abnormalities on organisms.
Can cause genetic disorders affecting development and function.