Unit notes and practice questions
Everything here is for unit 4 of the Grade 10 Biology textbook: what the chapter covers, the short notes, practice questions with their answers, and the lesson video where one exists.
The cards filed under this chapter on the Grade 10 Biology page. Open one at a time.
When you use it
Use when identifying what separates during Anaphase I versus Anaphase II of meiosis.
Watch out
In Anaphase I, homologous chromosome pairs separate while sister chromatids stay joined at the centromere. Centromeres divide and sister chromatids separate only in Anaphase II.
Drafted from Grade 10 Biology, pages 81-93, then checked twice before it went up
| Feature | Mitosis | Meiosis |
|---|---|---|
| Site of division | Somatic (body) cells | Reproductive organs (testes, ovaries) |
| Number of divisions | 1 nuclear division | 2 nuclear divisions |
| Daughter cells formed | 2 genetically identical cells | 4 genetically diverse gametes |
| Chromosome number | (Diploid) | (Haploid) |
| Primary function | Growth, tissue repair, replacement | Gametogenesis (gamete production) |
When you use it
Use when contrasting the two types of nuclear cell division and their biological roles.
Watch out
Mitosis preserves the chromosome number (), whereas meiosis halves it () through two successive divisions.
Drafted from Grade 10 Biology, pages 81-93, then checked twice before it went up
| Interphase Stage | Key Cellular Events |
|---|---|
| G1 Phase (First Gap) | Metabolic activity, cell growth, accumulation of DNA building blocks and energy |
| S Phase (Synthesis) | DNA replication and chromosome duplication |
| G2 Phase (Second Gap) | Energy replenishment, protein synthesis, organelle duplication, division prep |
When you use it
Use when identifying the sequence of preparatory events occurring before mitotic cell division.
Watch out
DNA synthesis occurs strictly during the S phase, never in G1 or G2.
Drafted from Grade 10 Biology, pages 81-93, then checked twice before it went up
10 multiple-choice questions written against this chapter, each with its answer and the reason. Try one before you open the answer.
Question 1
During which phase of interphase does DNA replication (synthesis) take place?
Answer: A S phase
Why
The S phase (Synthesis phase) is the specific stage of interphase where DNA replication occurs.
Question 2
Which scientist postulated the cell doctrine in 1858, stating that new cells arise from pre-existing cells?
Answer: B Rudolf Virchow
Why
In 1858, Rudolf Virchow postulated that new cells arise from pre-existing cells by cell division.
Question 3
In mitotic cell division, one diploid (2n) parent cell divides to produce:
Answer: A Two diploid (2n) identical daughter cells
Why
Mitosis produces two diploid (2n) daughter cells that are genetically identical to the parent cell.
Question 4
Which international honor was awarded to the Ethiopian geneticist Dr. Melaku Worede in 1989 for preserving native seeds?
Answer: A Right Livelihood Award
Why
Dr. Melaku Worede received the Right Livelihood Award in 1989 for his work in preserving Ethiopia's genetic wealth.
Question 5
During which phase of mitosis do duplicated chromosomes line up end-to-end along the equatorial plane (metaphase plate)?
Answer: B Metaphase
Why
During metaphase, mitotic spindles are fully developed and chromosomes line up along the centre or metaphase plate of the cell.
Question 6
Why can plant cells NOT simply pinch off in the middle during cytokinesis like animal cells?
Answer: A They have a rigid cell wall outside the cell membrane
Why
Because plant cells have a hard cell wall, the cytoplasm cannot simply pinch off; instead, a new wall is laid down between daughter cells forming a middle lamella.
Question 7
What is the total number and chromosome condition of daughter cells formed at the end of meiosis?
Answer: B Four haploid (n) cells
Why
Meiosis involves two nuclear divisions that produce four haploid (n) daughter cells (gametes).
Question 8
As a living cell grows larger in size, what main physical change causes it to trigger cell division?
Answer: A Its surface area to volume ratio becomes too low for simple diffusion
Why
As a cell grows, it develops a low surface area to volume ratio. Simple diffusion becomes inadequate to transport materials, so the cell divides.
Question 9
Which event specifically occurs during Anaphase I of meiosis?
Answer: A Homologous chromosome pairs separate and move to opposite poles
Why
In Anaphase I, homologous chromosome pairs separate to opposite poles (reducing chromosome number to haploid), while centromeres do not split until Anaphase II.
Question 10
What occurs when the internal regulatory and controlling system of the cell cycle fails?
Answer: A Cells divide excessively in an unregulated manner, forming cancer
Why
Cancer occurs when cell cycle control factors fail, causing cells to divide continuously in an unregulated manner and invade other body tissues.
The app holds 12 questions on this unit, marked as you go. These are the first 10.
Unit 4 runs from page 81 to page 93 of the Ministry of Education edition.
Ministry of Education edition, English, 177 pages
Temari turns this chapter into timed practice and marks it as you go, with an AI tutor to explain anything that did not land.
Start free
Temari.et is also an Android app, free on Google Play.
