1. Importance & Functions of the Cell Cycle
Why is the cell cycle important to organisms?
The cell cycle is important because it is how cells reproduce themselves. Cell reproduction allows organisms to grow, develop, replace old or damaged cells, and produce new cells.
What are the two major phases of the cell cycle?
Interphase (longest, growth & DNA replication) and Mitotic phase (division).
What occurs in the Mitotic phase?
Cell divides into two daughter cells.
What are the two major types of cells?
Prokaryotic (simpler, only unicellular) and Eukaryotic (unicellular & multicellular).
Explain why atoms are the basic building blocks of all living things.
Atoms → molecules → cells → living things.
List 4 important functions of the cell cycle.
Reproduction, Growth, Replacement, Repair.
How long does the cell cycle last?
8 minutes to 1 year; average in humans is 24 hours.
What are the two stages of the Mitotic phase?
Mitosis (nucleus divides) and Cytokinesis (cytoplasm divides).
Do all cells in a multicellular organism do the same thing?
No; they use only the instructions needed for their role.
Unicellular organisms must do all survival tasks within one cell. List 5.
Ingest food, respond to environment, excrete waste, grow, reproduce.
What type of organisms reproduce through the cell cycle? When these organisms reproduce are the offspring different than the parent?
Unicellular organisms reproduce through the cell cycle. The offspring they produce are identical to the parent.
What cells stop in G1 phase?
Mature nerve cells in the brain.
List and describe the four phases of mitosis.
Prophase: Chromatin coils → chromosomes, spindle fibers form.
Metaphase: Chromosomes align in middle.
Anaphase: Sister chromatids separate, cell elongates.
Telophase: Chromosomes uncoil, nuclear membranes reform.
What are the three types of plant tissue?
Dermal (cover), Vascular (transport), Ground (photosynthesis).
Why are stem cells important?
They are undifferentiated and can become any cell type.
How is the growth of a multicellular organism related to the cell cycle?
In order for a multicellular organism to grow it must add new cells. The cell cycle is the process of producing new cells.
When does the cell duplicate its DNA?
S phase of interphase; produces sister chromatids held by centromeres.
When chromatin coils tightly what is it called?
Chromosomes; occurs in prophase.
What are the 4 types of animal tissue?
Muscle (movement), Connective (support), Nervous (messages), Epithelial (protection).
Does the embryo or adult have more stem cells?
Embryo has more.
In a multicellular organism that is no longer growing why is the cell cycle important?
It is important for replacement of worn-out cells and repair of damaged cells.
When are organelles replicated?
Throughout interphase; instructions mostly in DNA, mitochondria/chloroplasts self-replicate.
What is cytokinesis? How is it different in plant vs animal cells?
Animal: Membrane contracts → furrow forms.
Plant: Cell plate forms → new cell wall
Give an example of an organ in a plant and animal.
Plant: Leaf → photosynthesis. Animal: Stomach → digestion.
Where are stem cells found in plants?
In meristems at root and stem tips.