What is the purpose of meiosis in sexually reproducing organisms?
To produce gametes (sperm and egg cells) with half the number of chromosomes as the parent cell.
What is the main purpose of mitosis in multicellular organisms?
To produce identical cells for growth, repair, and maintenance.
What is the main purpose of the cell cycle?
To prepare a cell for division and produce two identical daughter cells.
What is the shape of DNA, often described as a twisted ladder?
Double helix.
What are checkpoints in the cell cycle?
Mechanisms that monitor and verify whether the cell is ready to proceed to the next phase.
In which stage of meiosis does crossing over occur, leading to genetic variation?
Prophase I.
During which phase of mitosis do chromosomes align in the middle of the cell?
Metaphase.
Which phase of the cell cycle is where the cell grows and performs normal functions?
G1 phase.
What is a chromosome made of?
DNA and proteins (specifically histones).
What is the primary function of the G1 checkpoint?
To ensure the cell has adequate size, nutrients, and undamaged DNA before DNA synthesis.
How many cells are produced at the end of meiosis, and are they genetically identical or different?
Four genetically different cells.
What structure pulls sister chromatids apart during anaphase?
The spindle fibers.
During which cell cycle stage does DNA replication occur?
S phase.
What is Trinitee's and Brooke's major?
Free Points :)
Biology
What percent is your final exam?
30%
What is the main difference between Anaphase I and Anaphase II in meiosis?
In Anaphase I, homologous chromosomes are separated; in Anaphase II, sister chromatids are separated.
What is the difference between cytokinesis in plant cells and animal cells?
In plant cells, a cell plate forms to divide the cells, while in animal cells, a cleavage furrow forms.
What is the name of the phase where the cell prepares for mitosis by producing proteins and organelles needed for cell division?
G2 phase.
How many chromosomes do humans have in each somatic (body) cell?
46 chromosomes.
What happens to a cell if it fails the G2 checkpoint?
The cell cycle is halted, and the cell either repairs the DNA or undergoes apoptosis (programmed cell death) if the damage cannot be fixed.
If a diploid cell has 46 chromosomes, how many chromosomes will each gamete have after meiosis?
23 chromosomes.
What phase precedes mitosis and involves DNA replication?
Interphase.
What is the main purpose of the G1 and G2 checkpoints in the cell cycle?
To ensure the cell is ready for DNA synthesis (G1 checkpoint) and mitosis (G2 checkpoint), preventing errors.
What term describes the section of a chromosome that codes for a specific protein or trait?
Gene.
How do cancer cells bypass normal cell cycle controls?
They often have mutations in genes that regulate the cell cycle, such as p53, allowing them to divide uncontrollably.