Year 10 Science · Unit 1 · Lesson 3
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Learning Goals
Compare two
Complete the table to compare mitosis and meiosis.
| Feature | Mitosis | Meiosis |
|---|---|---|
| Number of daughter cells produced | ||
| Chromosome number in daughter cells (human) | ||
| Are daughter cells genetically identical to parent? | ||
| Main purpose in the human body | ||
| Where does it occur? | ||
| Does crossing over occur? |
Real-world context
Every day, your skin loses thousands of cells through friction and everyday wear. Skin cells at the base layer (called the stratum basale) divide constantly to replace those lost. In 2018, researchers at the QIMR Berghofer Medical Research Institute in Brisbane found that some skin cells can divide over 10,000 times in a lifetime before showing signs of wear.
(a) Trace the sequence of events when a skin cell divides to repair a wound. Begin with DNA replication and end with two identical daughter skin cells. Include the role of at least two enzymes.
(b) If a mutation occurs in a skin cell during DNA replication, will it be passed on to offspring? Explain why or why not, using your knowledge of mitosis and meiosis.
1. A human egg cell contains 23 chromosomes. After fertilisation with a sperm cell, the zygote contains 46 chromosomes. Name the type of cell division that produced the egg and sperm, and explain why it was necessary for these cells to have only half the normal chromosome number.
2. The acronym PMAT is used to remember the stages of mitosis (Prophase, Metaphase, Anaphase, Telophase). In which stage do chromosomes line up in the middle of the cell, and why is this important for accurate DNA distribution?
Wrap Up
In one sentence, what was the main idea of this lesson?