Week 9 · Readings & resources

Week 9 — Readings & Resources

Introduction to Biology Free sample edition

Your primary reading is Chapter 9 (in this module). Everything below is the optional, go-deeper layer — pick what helps, skip the rest.

How to use this page

This page has 11 items (5 readings and 6 videos). Allow 85–102 minutes for everything. Each group points back to the matching chapter section and class-session segment, so use the full menu when you want more, or take the quick path below.

Every video here has captions: turn them on with the CC button in the player. The chapter covers the same ideas in text.

Pick-one quick path (18–20 min total)

① The loop: grow, copy, prepare, divide

Chapter 9, Section “Read the cell cycle as a loop” · Session 1, Segment 1, “The cell cycle is a loop” · Remember: most of a cell's life is interphase, and the DNA is copied in the S phase, before mitosis begins.

The Cell Cycle — Nucleus Biology — a short narrated animation that walks the loop from G1 through S and G2 to the M phase; pause when it reaches the S phase and say out loud what gets copied there. (video, 4 min) (captions: automatic)
Mitosis & the Cell Cycle: How Cells Clone Themselves: Crash Course Biology #29 — CrashCourse — a lively episode that covers the whole cycle, the phases of mitosis, and what happens when the cycle's controls fail; it names more control proteins than this course asks for, so hold on to the order of the stages and let the extra names go by. (video, 11 min) (captions: creator)
How do cells divide? — MedlinePlus Genetics — a short plain-language page from the National Library of Medicine that contrasts the two kinds of cell division; read the mitosis paragraph closely and treat the meiosis paragraph as a preview. This builds on Week 4's work comparing cells and relating each organelle, the nucleus included, to its job. Use it while working through the Week-9 module overview. (reading, 3–5 min)

② Mitosis, step by step

Chapter 9, Section “Run mitosis in order: prophase to telophase” · Session 1, Segment 3, “Mitosis, in order” · Remember: prophase, metaphase, anaphase, telophase, in that order, and the sister chromatids separate in anaphase.

Mitosis: Splitting Up is Complicated - Crash Course Biology #12 — CrashCourse — a fast episode that follows a cell through copying its DNA and then each phase of mitosis; it uses some terms this course skips, so listen for the moment the sister chromatids are pulled apart and name that phase. (video, 11 min) (captions: creator)
Phases of Mitosis — Bozeman Science — a steady walk-through of the phases with real microscope images; it counts prometaphase as its own phase, while this course treats it as the end of prophase, so fold that step into prophase as you watch. (video, 11 min) (captions: creator)

③ When division loses its brakes

Chapter 9, Section “Meet the brakes: checkpoints and cancer” · Session 2, Segment 6, “The brakes, and what happens without them” · Remember: proto-oncogenes push the cycle forward, tumor-suppressor genes brake it, and cancer is division without the brakes.

What Is Cancer? — National Cancer Institute — the federal cancer agency's plain-language overview; read the sections on how cancer cells differ from normal cells, how cancer develops, and the types of genes that cause cancer, and skip the long list of cancer types at the end. (reading, 8–12 min)
The Eukaryotic Cell Cycle and Cancer — HHMI BioInteractive — a click-through interactive that steps around the cell cycle and shows what happens at its checkpoints when a control gene is mutated; it names regulator proteins this course leaves out, so keep your eye on where the checks happen and what a broken brake does. (reading, 10–15 min)
What is Cancer? — Bozeman Science — a calm explainer that frames cancer as cell division out of control and walks through the genes involved; listen for the accelerator and the brake as you watch. (video, 7 min) (captions: creator)
Chemo Sucks. Science Is Changing That — SciShow — a look at why classic chemotherapy is so hard on the body and at newer treatments that aim more precisely; connect it to this week's point that a drug aimed at dividing cells hits healthy dividing cells too. (video, 9 min) (captions: creator)

④ Counting the dividing cells

Chapter 9, Section “Count the dividing cells: the mitotic index” · Session 2, Segment 7, “Putting a number on division” · Remember: the mitotic index is the cells in mitosis divided by all the cells counted, times 100.

Online Onion Root Tips — The Biology Project — the virtual microscope activity behind this week's lab, offered here as a fallback if the lab link moves; you sort photographed onion root-tip cells into interphase or one of the four mitosis phases, then count each group. It shows a different number of cells than this week's model count of 100, so your index will not match 20%. (reading, 10–15 min)

Optional one-stop reference (free online reference)

Mitosis — National Human Genome Research Institute Talking Glossary — the course's free glossary of genetic terms, open at its entry for mitosis; read the short definition, and skip any mention of how mitosis differs from meiosis until next week. (reading, 1–2 min)

Heads-up (links rot): these point to outside sites that occasionally move or rename pages. If a link ever fails, tell your instructor and use the reference above in the meantime.

Provenance: Built with The Course Maker · samples.thecoursemaker.com