Lesson 9
Cells & Repair
Cells & Repair
New cells come from these.
existing cells
Cells need these materials from food to grow and make more cells
nutrients
Which cell structure controls what enters and leaves a cell?
the cell membrane
This area near the end of a growing bone is where new bone forms as a child grows.
a growth plate
Name the cell boundary that controls what enters and leaves. Then name the material inside where many cell activities occur.
The cell membrane and cytoplasm.
What is the difference between unicellular and multicellular organisms?
Unicellular organisms have one cell. Multicellular organisms have many cells
These cell structures build proteins using instructions and materials
ribosomes
What cellular process adds new cells during both growth and healing?
Existing cells grow and split to make new cells
A conclusion based on observations and evidence is called this.
is an inference
Which type of cell has a nucleus: prokaryotic or eukaryotic? What about the other type?
Eukaryotic cells have a nucleus. Prokaryotic cells do not
These structures make energy available for cell activities in plant and animal cells
mitochondria
Do both humans and plants grow through processes that involve making new cells? Explain.
Yes. Cells in both humans and plants can make new cells.
Which type of new cell helps fill a gap in skin? Explain why bone cells would not do the same job
New skin cells help fill the gap. Skin and bone cells have different functions
Match the terms: makes its own food, or gets food from other organisms. Use autotrophic and heterotrophic.
Autotrophic: makes its own food. Heterotrophic: gets food from other organisms.
Name two structures that plant cells have and animal cells do not. Explain one job for each.
Chloroplasts help make food using light. A cell wall forms a firm outer layer.
What happens to growth plates over time as children’s bones develop?
Growth plates gradually fill in with bone.
A model shows skin cells growing and splitting as a gap shrinks. Give a claim, evidence from the model, and reasoning about healing.
Claim: New cells help fill the gap. Evidence: The model shows cells splitting as the gap shrinks.
A scientist changes nutrient amount and measures bacterial growth. Identify the independent and dependent variables, plus one possible control.
Independent: nutrient amount. Dependent: bacterial growth. Possible control: the time allowed for growth.
Explain how the cell membrane, ribosomes, and mitochondria work together to support a cell.
The membrane controls materials entering and leaving. Ribosomes build proteins. Mitochondria make energy available.
Explain one similarity and one difference between growth and healing at the cellular level.
Both involve making new cells. Growth adds to body structures. Healing repairs damaged structures.