Cell Cycles
What are the cell cycles?
There are two ways in which cells change and divide; these include mitosis and meiosis.
Mitosis occurs during the vegetative or somatic portion of the plant's life cycle, allowing a single cell to divide into two. Mitosis is associated with growth.
Meiosis occurs during reproduction to create cells with half the chromosome number to create a new phase of the life cycle. Meiosis is associated with sexual reproduction.
Subtopics
Laboratory
Allium (onion) root tip:
Cell in Prophase
Cell in Metaphase
Cell in Anaphase
Cell in Telophase
Above: Allium root tip showing different stages of mitosis
Questions for Thought
What is mitosis, in the simplest terms?
What steps are required before a cell can enter mitosis or meiosis?
How does a cell create two copies of itself in mitosis, without losing genetic information?
Where could you find examples of mitosis on a daffodil?
How is mitosis different from meiosis?
Why is crossing-over in meiosis important for genetic diversity?
Where could you find examples of meiosis on a daffodil?
How are karyokinesis and cytokinesis connected in plants, and what would be the effect if they weren't linked?
See also the tissues and propagation sections for comparison questions
Additional Resources
Pollen and Plant Stress: podcast discussion of how env't factors like UV radiation can disrupt meiosis and make gymnosperms sterile, and indicators of this same mechanism in the fossil record during extinction events (In Defense of Plants 13Feb2022)
Cell division in microalgae: mitosis revealed in detail (1Feb2022 Universitat Bielefeld; Peer-reviewed article: von der Heyde & Hallmann 2022)
An awesome Ophioglossum (In Defense of Plants 2May2016): this is a strange fern with 1,260 chromosomes… the largest in the biological world!!!
Why elephants rarely get cancer (EurekAlert 2015)
“Molecular scissors” required for successful chromosome separation in sex cells (Stower's Institute for Medical Research 31Oct2014)
A mitosis mystery solved: how chromosomes align perfectly in a dividing cell (Whitehead Institute 12Feb2012; Peer-reviewed article: Kiyomitsu & Cheeseman 2012)