PART I · SHORT RESPONSE第一部分 · 短答题AP-style MCQ + ON/BC short answer · 25 marksAP 风格选择题 + 安/卑省考短答 · 共 25 分
Section A · Short ResponseA 部分 · 短答题
Mix of multiple-choice and short-answer items. For MCQs, circle the letter and write one sentence justifying your choice. For short-answer items, answer in complete sentences. No calculator required in Part I.本节包含选择题与短答题。选择题请圈出字母答案，并用一句话说明理由。短答题请用完整句子作答。第一部分无需计算器。
Meiosis I is often called the reductive division because it reduces the chromosome number from diploid to haploid.减数分裂 I 常被称为减数分裂，因为它将染色体数目从二倍体降至单倍体。
(a)Describe what occurs during synapsis in Prophase I, including the structures formed and the genetic event that takes place.描述前期 I 联会时发生的事件，包括形成的结构和发生的遗传事件。[3]
(b)Explain the key difference between Anaphase I of meiosis and Anaphase of mitosis in terms of what separates and what remains joined.从分离的物质和保持连接的物质角度，解释减数分裂后期 I 与有丝分裂后期的关键区别。[2]
(c)State the chromosome content (number and ploidy) of the cells produced at the end of Meiosis I, starting from a cell with 2n = 10.从一个 2n = 10 的细胞出发，写出减数分裂 I 结束时产生的细胞的染色体含量（数目和倍性）。[1]
Q5MEDIUM中🇨🇦 AB阿AB Diploma-style阿尔伯塔毕业考风格§5 Meiosis II and Gamete Formation减数分裂 II 与配子形成 · Biology 30-C1[8 marks][8 分]
A human primary spermatocyte (2n = 46) undergoes complete meiosis.一个人类初级精母细胞（2n = 46）经历完整的减数分裂。
(a)State the number of cells produced at the end of Meiosis I and at the end of Meiosis II, and the chromosome number in each.写出减数分裂 I 结束和减数分裂 II 结束时产生的细胞数目，以及各细胞中的染色体数目。[3]
(b)State the key event in Anaphase II that distinguishes it from Anaphase I, and explain what happens to the chromosome number per cell as a result.写出减数分裂后期 II 区别于后期 I 的关键事件，并解释因此每个细胞染色体数目发生的变化。[2]
(c)Explain why fertilization restores the diploid chromosome number, and state the biological significance of this restoration.解释受精为何能恢复二倍体染色体数目，并说明这种恢复的生物学意义。[2]
(d)No DNA replication occurs between Meiosis I and Meiosis II. Explain why this is necessary for the correct outcome of meiosis.减数分裂 I 与 II 之间不发生 DNA 复制。解释为何这对减数分裂正确结果是必要的。[1]
PART II · EXTENDED RESPONSE第二部分 · 简答题AP-feeder FRQ + honors · 30 marksAP 衔接简答题 + 荣誉级 · 共 30 分
Section B · Extended ResponseB 部分 · 简答题
Show every step of reasoning. Support each claim with biological evidence or logic. Write in complete sentences. Conclude each sub-part with a clear, direct answer statement.每一步推理都要写出。用生物学证据或逻辑支撑每个论点。用完整句子作答。每个子问题以清晰直接的答案陈述收尾。
A cell with 2n = 8 chromosomes is observed at various stages of its cell cycle.一个具有 2n = 8 条染色体的细胞在细胞周期不同阶段被观察到。
(a)State the number of chromosomes and chromatids present in this cell (i) at the start of G1, (ii) at the end of S phase, and (iii) at the end of anaphase of mitosis.写出该细胞在以下各阶段含有的染色体数目和染色单体数目：(i) G1 期开始时；(ii) S 期结束时；(iii) 有丝分裂后期结束时。[3]
(b)Describe the purpose of the G1 checkpoint and the G2 checkpoint. State what each checks before allowing the cell to proceed.描述 G1 检验点和 G2 检验点的作用。写出各检验点在允许细胞继续前检查的内容。[2]
(c)Interphase is sometimes incorrectly called a "resting phase." Using specific events in G1, S, and G2, explain why this description is inaccurate.间期有时被错误地称为"静止期"。利用 G1、S 和 G2 中的具体事件，解释为何此描述不准确。[2]
A student examines cells under a microscope. For each description below, identify the mitotic phase and justify your identification using two observable features.一名学生在显微镜下观察细胞。对于以下每条描述，辨认有丝分裂时期，并用两个可观察特征说明理由。
(a)Chromosomes are condensed and visible; the nuclear envelope is intact; no spindle fibers are visible yet.染色体凝缩可见；核膜完整；尚无可见纺锤丝。[2]
(b)Chromosomes are lined up along the equatorial plane; the nuclear envelope is absent; spindle fibers attach at the kinetochores.染色体排列在赤道板；核膜缺失；纺锤丝通过动粒附着于染色体。[2]
(c)Two groups of chromosomes are present at opposite poles; nuclear envelopes are beginning to reform; the cell is elongated.两组染色体位于两极；核膜开始重新形成；细胞已伸长。[2]
(d)Describe the function of the spindle assembly checkpoint (metaphase checkpoint) and explain how failure of this checkpoint can lead to aneuploidy in daughter cells.描述纺锤体组装检验点（中期检验点）的功能，并解释该检验点失效如何导致子细胞染色体数目异常（非整倍体）。[2]
Q8MEDIUM中🇨🇦 BC卑BC Provincial-style卑诗省考风格§6 Mitosis vs Meiosis and Genetic Variation有丝分裂 vs 减数分裂与遗传变异 · Biology 12[8 marks][8 分]
Compare mitosis and meiosis, and explain the sources of genetic variation that meiosis produces but mitosis does not.比较有丝分裂与减数分裂，并解释减数分裂产生而有丝分裂不产生的遗传变异来源。
(a)For each of the following features, state whether it applies to mitosis, meiosis, or both: (i) number of divisions; (ii) ploidy of daughter cells; (iii) genetically identical daughter cells; (iv) crossing over; (v) independent assortment. Organize your answer in a table.对于以下每个特征，写出它适用于有丝分裂、减数分裂，还是两者均适用：(i) 分裂次数；(ii) 子细胞倍性；(iii) 子细胞基因相同；(iv) 交叉互换；(v) 独立分配。用表格组织答案。[4]
(b)Explain how crossing over in Prophase I generates genetic variation. Be specific about which chromatids exchange segments and where exchanges occur.解释前期 I 中的交叉互换如何产生遗传变异。具体说明哪些染色单体交换片段以及交换发生的位置。[2]
(c)A species has $n = 5$ chromosome pairs. Using the formula $2^n$, calculate the number of genetically different gametes that can be produced by independent assortment alone. Show your calculation.某物种有 $n = 5$ 对染色体。使用公式 $2^n$，计算仅靠独立分配能产生的基因不同配子数目。写出计算过程。[2]
Q9HARD难Honors荣誉级🇺🇸 US美AP-feeder FRQAP 衔接简答题§7 Cell-Cycle Control and Cancer细胞周期调控与癌症 · HS-LS1-4[7 marks][7 分]
Cancer cells are characterized by uncontrolled cell division that ignores normal cell-cycle checkpoints.癌细胞的特征是无控制地分裂，无视正常的细胞周期检验点。
(a)Distinguish between proto-oncogenes and tumour-suppressor genes. Explain what happens to the cell cycle when (i) a proto-oncogene mutates into an oncogene, and (ii) a tumour-suppressor gene is inactivated.区分原癌基因与肿瘤抑制基因。解释以下情况对细胞周期的影响：(i) 原癌基因突变为癌基因；(ii) 肿瘤抑制基因失活。[3]
(b)List three characteristics that distinguish cancer cells from normal cells in terms of division behavior, adhesion, and growth factor dependence.列举三个区分癌细胞与正常细胞的特征，涉及分裂行为、细胞粘附性和生长因子依赖性。[2]
(c)Explain why cancer typically requires multiple mutations (not just one) to develop, and why this is relevant to understanding cancer risk over a lifetime.解释为何癌症的发展通常需要多个突变（而非仅一个），以及这与理解终身癌症风险的关系。[2]
PART III · MODELING / APPLIED第三部分 · 建模与应用AB Diploma + Universal · 26 marks阿省毕业考 + 通用题型 · 共 26 分
Section C · Modeling and ApplicationsC 部分 · 建模与应用
Support interpretations with biological reasoning. Where calculations are required, show all working. Conclude each question with a sentence in context. Calculator permitted throughout Part III.用生物学推理支撑解读。需要计算时写出完整步骤。每题以结合情境的完整句子作答。第三部分全程可用计算器。
Q10MEDIUM中🇨🇦 AB阿AB Diploma-style阿尔伯塔毕业考风格§4 + §5 Meiosis I + II (applied)减数分裂 I + II（应用） · Biology 30-C1[8 marks][8 分]
A cell with 2n = 6 chromosomes undergoes meiosis. The cell contains three pairs of homologous chromosomes (pair 1: long; pair 2: medium; pair 3: short).一个 2n = 6 的细胞进行减数分裂。该细胞含三对同源染色体（第 1 对：长；第 2 对：中；第 3 对：短）。
(a)Draw and label a simple diagram showing the arrangement of the three bivalents at the Metaphase I plate. Show two possible orientations for one of the pairs to illustrate independent assortment.画出并标注一个简单示意图，显示三个二价体在中期 I 赤道板的排列。对其中一对画出两种可能方向，以说明独立分配。[3]
(b)After complete meiosis, state the total number of gametes produced and the chromosome number in each. Explain whether all four gametes are genetically identical, and give two reasons why they may differ.完成减数分裂后，写出产生的配子总数及每个配子的染色体数目。解释四个配子是否基因相同，并给出两个它们可能不同的原因。[3]
(c)Using the formula $2^n$, calculate the number of chromosomally distinct gametes that independent assortment alone could produce from this cell. Show your working.使用公式 $2^n$，计算仅靠独立分配该细胞能产生的染色体组合不同的配子数目。写出计算过程。[2]
Q11HARD难Honors荣誉级🇨🇦 AB阿🇺🇸 US美AB Diploma-style阿尔伯塔毕业考风格§5 Spermatogenesis vs Oogenesis精子发生 vs 卵子发生 · Biology 30-C2[9 marks][9 分]
Spermatogenesis and oogenesis both use meiosis to produce gametes, but they differ in the number of functional cells produced and in the distribution of cytoplasm.精子发生与卵子发生均通过减数分裂产生配子，但产生的功能性细胞数目和细胞质分配方式不同。
(a)For spermatogenesis: state the starting cell, the number and chromosome content of cells after Meiosis I, and the total number of functional spermatozoa produced after Meiosis II.对于精子发生：写出起始细胞、减数分裂 I 后细胞的数目和染色体含量，以及减数分裂 II 后产生的功能性精子总数。[3]
(b)For oogenesis: explain why one primary oocyte produces only one functional egg rather than four, and state the fate of the other three cells.对于卵子发生：解释为何一个初级卵母细胞只产生一个功能性卵子而非四个，并说明另外三个细胞的命运。[3]
(c)Explain the biological advantage of unequal cytokinesis in oogenesis compared with the equal cytokinesis in spermatogenesis.与精子发生中均等的胞质分裂相比，卵子发生中不均等胞质分裂具有何种生物学优势？[2]
A research team is comparing two cell populations: Population A consists of cells undergoing normal mitosis in a tissue sample; Population B consists of cancer cells isolated from a tumour.一个研究团队正在比较两个细胞群体：种群 A 是组织样本中正常进行有丝分裂的细胞；种群 B 是从肿瘤中分离的癌细胞。
(a)The researchers find that cells in Population A spend approximately 90% of their cell cycle in interphase and only 10% in M phase. Explain why this ratio is biologically expected and what would happen if the G1 and G2 checkpoints were bypassed.研究人员发现种群 A 中细胞约 90% 的细胞周期时间处于间期，仅 10% 处于 M 期。解释为何这一比例具有生物学预期，以及如果 G1 和 G2 检验点被绕过会发生什么。[3]
(b)Population B cells show abnormal chromosome numbers (aneuploidy). Propose two specific checkpoint failures that could produce aneuploid daughter cells, and explain the mechanism by which each failure leads to aneuploidy.种群 B 细胞显示染色体数目异常（非整倍体）。提出两个可能导致非整倍体子细胞的具体检验点失效，并解释每种失效导致非整倍体的机制。[3]
(c)Crossing over during meiosis introduces genetic variation in sexually reproducing organisms. Explain why this variation is advantageous for the long-term survival of a species but does not occur in mitosis.减数分裂中的交叉互换为有性生殖生物引入遗传变异。解释为何这种变异有利于物种的长期存续，以及为何有丝分裂中不发生交叉互换。[2]
(d)State one external environmental factor that can increase the rate of mutation and thus increase cancer risk.写出一种可增加突变率从而增加癌症风险的外部环境因素。[1]
🇺🇸 US NGSS美国 NGSSHS-LS1-4 · HS-LS3-2
🇨🇦 Ontario安大略SBI3U · Cell division unit细胞分裂单元
🇨🇦 British Columbia不列颠哥伦比亚Biology 12: Cell division, mitosis, meiosis生物 12：细胞分裂、有丝分裂、减数分裂
🇨🇦 Alberta阿尔伯塔Biology 30 Unit C · 30-C1 · 30-C2 · Spermatogenesis/Oogenesis Honors精子/卵子发生为荣誉级
Full Syllabus Map lives in ../Study Guides/Unit_4_Cell_Division_and_the_Cell_Cycle.html. Spermatogenesis/oogenesis (Q11) and proto-oncogene/tumour-suppressor molecular detail (Q12) are Honors / AB Biology 30 content.完整大纲对照表见 ../Study Guides/Unit_4_Cell_Division_and_the_Cell_Cycle.html。精子发生/卵子发生（Q11）及原癌基因/肿瘤抑制基因分子细节（Q12）为荣誉级 / 阿尔伯塔 Biology 30 内容。