9th grade · Science · Unit 1 of 10
Cells from Cells
DNA, mitosis and growth
What your child practices
How cells copy their DNA and divide by mitosis, the stages in order, why cells divide for growth and healing, and what can go wrong when cell growth isn't controlled.
Arizona Academic Standards learning standard: HS.L1U1.22 · cell division and growth
How we explain it
Children can open this short lesson before they practice.
- Before dividing, a cell copies its DNA so each new cell gets a full set.
- Mitosis stages in order: prophase, metaphase, anaphase, telophase.
- Cells divide for growth and healing. Uncontrolled division can cause cancer.
Example: In which stage do the chromosomes line up in the middle? Prophase: chromosomes condense. Next they line up in the middle: metaphase. Answer: metaphase
Cells from Cells in Arizona
In the Arizona Academic Standards, this is unit 1 of 10 in 9th grade Science, before Reproduction.
Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.
Source: Arizona Department of Education
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
What is a gene?
- A type of cell
- A protein only
- A section of DNA that carries instructions for a trait or protein
- A kind of organ
A section of DNA that carries instructions for a trait or protein
Hint: Genes are the units of heredity: sections of DNA with instructions.
Question 2
Put the stages of cell division in order, earliest first.
- ⚪Telophase: two new nuclei form
- 🔬Prophase: chromosomes condense
- ↔️Anaphase: chromosomes pull apart
- ➖Metaphase: chromosomes line up
Prophase: chromosomes condense → Metaphase: chromosomes line up → Anaphase: chromosomes pull apart → Telophase: two new nuclei form
Hint: Interphase: the cell grows and copies its DNA. Prophase: chromosomes become visible. Metaphase: they line up. Anaphase: they are pulled apart. Telophase: two nuclei form. Then the cell splits.
Question 3
Most of a cell's life is spent in…
- anaphase
- mitosis
- telophase
- interphase
interphase
Hint: Interphase is when the cell grows, does its job and copies its DNA.
Question 4
Which is a reason that damaged DNA can be harmful?
- DNA only affects color.
- DNA is outside the cell.
- Instructions copied incorrectly can lead to cells that do not work properly.
- DNA is not copied.
Instructions copied incorrectly can lead to cells that do not work properly.
Hint: Mutations change the instructions, and some change how a cell behaves.
Question 5
During which stage do chromosomes line up in the middle of the cell?
- anaphase
- telophase
- prophase
- metaphase
metaphase
Hint: In metaphase, chromosomes line up along the cell's center before being pulled apart.
Question 6
How are plant cells different in the last stage of cell division?
- They make a new nucleus only.
- They skip it.
- They explode.
- They build a new cell plate between the two cells.
They build a new cell plate between the two cells.
Hint: Plant cells have rigid walls, so a cell plate forms and becomes the new wall.