AP Biology Flashcards: Meiosis

What this deck covers

This deck focuses on Meiosis, giving you a quick way to review the definitions, rules, and examples that matter most for AP Biology.

How to use these flashcards

Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: Define gametogenesis.

Answer: The process of forming gametes through meiosis. Occurs in reproductive organs to produce sex cells.

Flashcard 2: What occurs during Prophase II?

Answer: Chromosomes condense, and spindle fibers form in each new cell. No DNA replication occurs between meiosis I and II.

Flashcard 3: What type of cells undergo meiosis?

Answer: Germ cells. Located in reproductive organs like ovaries and testes.

Flashcard 4: What is the result of Meiosis II?

Answer: Four genetically distinct haploid cells. Final products are gametes ready for fertilization.

Flashcard 5: What is the end result of meiosis in males?

Answer: Four viable sperm cells. All products are functional and capable of fertilization.

Flashcard 6: When does DNA replication occur in relation to meiosis?

Answer: Before Meiosis I, during the S phase of interphase. Ensures each chromosome consists of two sister chromatids.

Flashcard 7: What structures form during metaphase I?

Answer: Tetrads align at the metaphase plate. Tetrads are paired homologous chromosomes ready for separation.

Flashcard 8: What is synapsis?

Answer: The pairing of homologous chromosomes during Prophase I of meiosis. Enables crossing over and genetic recombination between chromosomes.

Flashcard 9: What can result from nondisjunction?

Answer: Aneuploidy, such as Down syndrome. Results in abnormal chromosome numbers in gametes.

Flashcard 10: Identify one key difference between mitosis and meiosis.

Answer: Mitosis results in two identical diploid cells; meiosis results in four diverse haploid cells. Meiosis enables sexual reproduction while mitosis enables growth.

Flashcard 11: What structures form during metaphase I?

Answer: Tetrads align at the metaphase plate. Tetrads are paired homologous chromosomes ready for separation.

Flashcard 12: Define tetrad in the context of meiosis.

Answer: A group of four chromatids formed by synapsis of homologous chromosomes. Forms when homologous chromosomes undergo synapsis during prophase I.

Flashcard 13: What is the primary function of meiosis?

Answer: To produce haploid gametes and ensure genetic diversity. Crucial for maintaining species chromosome number across generations.

Flashcard 14: How does meiosis contribute to genetic diversity?

Answer: Through crossing over and independent assortment. These mechanisms create unique genetic combinations in offspring.

Flashcard 15: What stage of meiosis is primarily responsible for Mendel's law of independent assortment?

Answer: Metaphase I. Random chromosome orientation creates independent allele combinations.

Flashcard 16: What is genetic recombination?

Answer: The production of offspring with combinations of traits differing from parents. Results from crossing over and independent assortment during meiosis.

Flashcard 17: How do meiosis and fertilization contribute to genetic variation?

Answer: Meiosis creates diverse gametes; fertilization combines them randomly. Each process independently shuffles genetic material.

Flashcard 18: What is genetic recombination?

Answer: The production of offspring with combinations of traits differing from parents. Results from crossing over and independent assortment during meiosis.

Flashcard 19: What is independent assortment?

Answer: The random orientation of homologous chromosome pairs during Metaphase I. Creates $2^n$ possible chromosome combinations where n = chromosome pairs.

Flashcard 20: What distinguishes Meiosis II from Meiosis I?

Answer: Meiosis II separates sister chromatids, not homologous chromosomes. Similar to mitosis but operates on haploid cells.

Flashcard 21: How many chromosomes are in a human gamete?

Answer: 23 chromosomes. Half the diploid number, enabling chromosome restoration at fertilization.

Flashcard 22: What occurs during Metaphase II?

Answer: Chromosomes line up individually along the metaphase plate. Unlike metaphase I, individual chromosomes align rather than homologous pairs.

Flashcard 23: Define gametogenesis.

Answer: The process of forming gametes through meiosis. Occurs in reproductive organs to produce sex cells.

Flashcard 24: What is crossing over?

Answer: The exchange of genetic material between homologous chromosomes during Prophase I. Creates new combinations of alleles, increasing genetic variation.

Flashcard 25: What happens during Anaphase I?

Answer: Homologous chromosomes are pulled to opposite poles of the cell. Reduces chromosome number from diploid to haploid in daughter cells.

Flashcard 26: What happens during Anaphase II?

Answer: Sister chromatids are pulled apart to opposite poles of the cell. Produces individual chromatids that become separate chromosomes.

Flashcard 27: What occurs during Metaphase II?

Answer: Chromosomes line up individually along the metaphase plate. Unlike metaphase I, individual chromosomes align rather than homologous pairs.

Flashcard 28: What occurs during Prophase I of meiosis?

Answer: Homologous chromosomes pair and exchange segments (crossing over). This creates genetic diversity through recombination of parental chromosomes.

Flashcard 29: How do meiosis and fertilization contribute to genetic variation?

Answer: Meiosis creates diverse gametes; fertilization combines them randomly. Each process independently shuffles genetic material.

Flashcard 30: Define tetrad in the context of meiosis.

Answer: A group of four chromatids formed by synapsis of homologous chromosomes. Forms when homologous chromosomes undergo synapsis during prophase I.

Flashcard 31: How many chromosomes are in a human gamete?

Answer: 23 chromosomes. Half the diploid number, enabling chromosome restoration at fertilization.

Flashcard 32: What stage of meiosis is primarily responsible for Mendel's law of segregation?

Answer: Anaphase I. Homologous chromosomes separate, distributing alleles to different gametes.

Flashcard 33: What is the ploidy level of cells after Meiosis I?

Answer: Haploid. Contains half the chromosome number of the parent cell.

Flashcard 34: What is the role of the spindle fibers during meiosis?

Answer: To separate chromosomes or chromatids to opposite poles. Attach to kinetochores and guide chromosome movement.

Flashcard 35: What is crossing over?

Answer: The exchange of genetic material between homologous chromosomes during Prophase I. Creates new combinations of alleles, increasing genetic variation.

Flashcard 36: What is the synaptonemal complex?

Answer: A protein structure that forms between homologous chromosomes during meiosis. Facilitates proper chromosome pairing and crossing over.

Flashcard 37: What is the main product of oogenesis?

Answer: One ovum and polar bodies. Polar bodies degenerate; only ovum is functional.

Flashcard 38: What is the synaptonemal complex?

Answer: A protein structure that forms between homologous chromosomes during meiosis. Facilitates proper chromosome pairing and crossing over.

Flashcard 39: What occurs during Prophase II?

Answer: Chromosomes condense, and spindle fibers form in each new cell. No DNA replication occurs between meiosis I and II.

Flashcard 40: When does DNA replication occur in relation to meiosis?

Answer: Before Meiosis I, during the S phase of interphase. Ensures each chromosome consists of two sister chromatids.

Flashcard 41: What happens during Anaphase II?

Answer: Sister chromatids are pulled apart to opposite poles of the cell. Produces individual chromatids that become separate chromosomes.

Flashcard 42: What is nondisjunction?

Answer: The failure of chromosomes to separate properly during meiosis. Can occur during anaphase I or II, disrupting normal separation.

Flashcard 43: What is spermatogenesis?

Answer: The process by which sperm cells are produced by meiosis. Occurs continuously after puberty in males.

Flashcard 44: What is the primary function of meiosis?

Answer: To produce haploid gametes and ensure genetic diversity. Crucial for maintaining species chromosome number across generations.

Flashcard 45: How many phases are in meiosis?

Answer: Two phases: Meiosis I and Meiosis II. Each phase consists of multiple sub-stages like prophase, metaphase, etc.

Flashcard 46: What stage of meiosis is primarily responsible for Mendel's law of independent assortment?

Answer: Metaphase I. Random chromosome orientation creates independent allele combinations.

Flashcard 47: What happens during Anaphase I?

Answer: Homologous chromosomes are pulled to opposite poles of the cell. Reduces chromosome number from diploid to haploid in daughter cells.

Flashcard 48: What is the end result of meiosis in females?

Answer: One viable ovum and polar bodies. Unequal cytoplasm division creates one large functional gamete.

Flashcard 49: What type of cells undergo meiosis?

Answer: Germ cells. Located in reproductive organs like ovaries and testes.

Flashcard 50: What is the significance of meiosis in sexual reproduction?

Answer: It ensures offspring have the same chromosome number as parents and introduces genetic variation. Prevents chromosome doubling and promotes evolution through variation.

Flashcard 51: What stage of meiosis is primarily responsible for Mendel's law of segregation?

Answer: Anaphase I. Homologous chromosomes separate, distributing alleles to different gametes.

Flashcard 52: What is the end result of meiosis in males?

Answer: Four viable sperm cells. All products are functional and capable of fertilization.

Flashcard 53: What is a chiasma?

Answer: The point where two homologous chromosomes exchange genetic material during crossing over. Visible evidence of crossing over between homologous chromosomes.

Flashcard 54: How does meiosis contribute to genetic diversity?

Answer: Through crossing over and independent assortment. These mechanisms create unique genetic combinations in offspring.

Flashcard 55: What is the ploidy level of cells after Meiosis I?

Answer: Haploid. Contains half the chromosome number of the parent cell.

Flashcard 56: What is synapsis?

Answer: The pairing of homologous chromosomes during Prophase I of meiosis. Enables crossing over and genetic recombination between chromosomes.

Flashcard 57: What is a chiasma?

Answer: The point where two homologous chromosomes exchange genetic material during crossing over. Visible evidence of crossing over between homologous chromosomes.

Flashcard 58: What is the result of Meiosis I?

Answer: Two haploid cells with duplicated chromosomes. Chromosome number is reduced but chromatids remain attached.

Flashcard 59: What is spermatogenesis?

Answer: The process by which sperm cells are produced by meiosis. Occurs continuously after puberty in males.

Flashcard 60: What is the result of Meiosis II?

Answer: Four genetically distinct haploid cells. Final products are gametes ready for fertilization.

Flashcard 61: What distinguishes Meiosis II from Meiosis I?

Answer: Meiosis II separates sister chromatids, not homologous chromosomes. Similar to mitosis but operates on haploid cells.

Flashcard 62: What is meiosis?

Answer: A type of cell division that reduces chromosome number by half, producing gametes. Essential for sexual reproduction and genetic diversity.

Flashcard 63: How many phases are in meiosis?

Answer: Two phases: Meiosis I and Meiosis II. Each phase consists of multiple sub-stages like prophase, metaphase, etc.

Flashcard 64: What is the function of polar bodies?

Answer: To discard extra chromosomes and cytoplasm during oogenesis. Ensures maximum resources go to the viable ovum.

Flashcard 65: What occurs during Prophase I of meiosis?

Answer: Homologous chromosomes pair and exchange segments (crossing over). This creates genetic diversity through recombination of parental chromosomes.

Flashcard 66: What is meiosis?

Answer: A type of cell division that reduces chromosome number by half, producing gametes. Essential for sexual reproduction and genetic diversity.

Flashcard 67: What is the difference between a diploid and a haploid cell?

Answer: Diploid cells have two sets of chromosomes, haploid cells have one set. Diploid = $2n$, haploid = $n$ chromosome sets.

Flashcard 68: What is the role of the spindle fibers during meiosis?

Answer: To separate chromosomes or chromatids to opposite poles. Attach to kinetochores and guide chromosome movement.

Flashcard 69: What is nondisjunction?

Answer: The failure of chromosomes to separate properly during meiosis. Can occur during anaphase I or II, disrupting normal separation.

Flashcard 70: What is independent assortment?

Answer: The random orientation of homologous chromosome pairs during Metaphase I. Creates $2^n$ possible chromosome combinations where n = chromosome pairs.

Flashcard 71: What is the function of polar bodies?

Answer: To discard extra chromosomes and cytoplasm during oogenesis. Ensures maximum resources go to the viable ovum.

Flashcard 72: What can result from nondisjunction?

Answer: Aneuploidy, such as Down syndrome. Results in abnormal chromosome numbers in gametes.

Flashcard 73: What is the result of Meiosis I?

Answer: Two haploid cells with duplicated chromosomes. Chromosome number is reduced but chromatids remain attached.

Flashcard 74: What is the end result of meiosis in females?

Answer: One viable ovum and polar bodies. Unequal cytoplasm division creates one large functional gamete.

Flashcard 75: What is the main product of oogenesis?

Answer: One ovum and polar bodies. Polar bodies degenerate; only ovum is functional.

Flashcard 76: What is the difference between a diploid and a haploid cell?

Answer: Diploid cells have two sets of chromosomes, haploid cells have one set. Diploid = $2n$, haploid = $n$ chromosome sets.