The Cell Cycle & Mitosis 1
During which stage of the cell cycle does a cell spend most of its time, and why is this important?
What is interphase, because this is when the cell grows, copies DNA, and prepares for division?
What process allows cells in a multicellular organism to become different from one another?
What is cell differentiation?
This type of animal tissue carries messages between the brain and body.
What is nervous tissue?
Name two ways multicellular organisms rely on cell division beyond reproduction.
For growth, repair, and replacement of worn-out or damaged cells.
Name one similarity and one difference between prokaryotic and eukaryotic cells.
Both have DNA and cytoplasm; eukaryotic cells have a nucleus and membrane-bound organelles, while prokaryotic cells do not.
Explain why sister chromatids are identical to each other.
Because they are exact copies of DNA made during the S stage of interphase.
If nearly all cells in an organism contain the same DNA, how do they become specialized for different jobs?
Different cells activate different parts of the DNA instructions.
Name the three types of plant tissues and briefly state each function.
Dermal: protection and prevents water loss
Vascular: transports water and nutrients
Ground: photosynthesis, storage, and support
Why can some injuries, like nerve damage, be permanent?
Because mature nerve cells stop dividing after interphase, so they cannot be replaced.
Why might prokaryotes be able to live in extreme environments while eukaryotes cannot?
Prokaryotes are simpler and more adaptable, with structures suited to harsh conditions.
Why must DNA be duplicated before mitosis begins?
So that each new daughter cell receives a complete set of genetic information.
Explain how stem cells differ from specialized cells.
Stem cells are unspecialized and can become many cell types, while specialized cells have specific structures and functions.
Why does an organ need more than one type of tissue to function properly?
Because different tissues perform specialized roles that work together for the organ’s job (e.g., stomach: muscle mixes food, epithelial lines, etc.).
How does the cell cycle help maintain homeostasis in an organism?
By replacing old or damaged cells and ensuring tissues and organs continue to function properly.
Explain why multicellular organisms are often more efficient than unicellular organisms.
Because they can divide tasks among specialized cells, making processes like transport and reproduction more efficient.
During which phase of mitosis do spindle fibers attach to chromosomes and line them up across the cell’s center?
What is metaphase?
Compare the role of animal stem cells and plant meristem cells.
Both are unspecialized cells that produce new cells for growth and repair, but animal stem cells are in tissues like bone marrow, while plant meristems are found in roots and shoots.
Give one example of how two organ systems in the human body work together to maintain homeostasis.
The respiratory and circulatory systems work together to provide oxygen to cells and remove carbon dioxide.
Why is it critical for mitosis to occur correctly without mistakes?
Because errors in chromosome separation can lead to genetic disorders or malfunctioning cells.
How does the structure of a leaf reflect its function as an organ?
It has dermal tissue for protection, ground tissue for photosynthesis, and vascular tissue for transport — all working together for food production.
Compare how cytokinesis differs in plant and animal cells, and explain why this difference exists.
In animal cells, the membrane pinches inward forming a furrow; in plant cells, a cell plate forms because the cell wall is too rigid to pinch inward.
Why is cell differentiation essential to the survival of multicellular organisms?
Because specialized cells allow division of labor, letting the organism perform complex tasks efficiently (e.g., muscle contraction, oxygen transport).
Describe how the shoot and root systems of plants depend on each other.
The roots absorb water and nutrients sent to the shoots, and shoots produce food (glucose) through photosynthesis that sustains the roots.
Explain how unicellular reproduction by cell division differs from multicellular growth by cell division.
In unicellular organisms, it produces a new organism; in multicellular organisms, it produces new cells within the same organism.
Predict what would happen if a multicellular organism lost the ability to control its cell cycle.
Uncontrolled division could cause cancer or tumor formation, disrupting normal tissue and organ function.