Biology Flashcards: Explain Meiosis And Genetic Diversity

What this deck covers

This deck focuses on Explain Meiosis And Genetic Diversity, giving you a quick way to review the definitions, rules, and examples that matter most for 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: What is a tetrad (bivalent) in meiosis?

Answer: Paired homologous chromosomes with four chromatids total. Forms when homologs pair during prophase I.

Flashcard 2: What is fertilization's main contribution to genetic diversity?

Answer: Random fusion of two genetically unique gametes. Combines genetic material from two different parents.

Flashcard 3: Which process shuffles whole maternal and paternal chromosomes into gametes: crossing over or independent assortment?

Answer: Independent assortment. Random distribution of intact parental chromosomes.

Flashcard 4: What is the chromosome number change in mitosis from start to finish?

Answer: Chromosome number stays the same. Diploid parent produces diploid daughter cells.

Flashcard 5: What is the genetic result of crossing over?

Answer: Recombinant chromatids with new allele combinations. New gene combinations increase genetic variation.

Flashcard 6: What does diploid mean in terms of chromosome sets?

Answer: Two sets of chromosomes ($2n$). Contains chromosomes from both parents in body cells.

Flashcard 7: What is aneuploidy?

Answer: An abnormal number of particular chromosomes. Common result of nondisjunction errors.

Flashcard 8: What is the genetic result of independent assortment?

Answer: New combinations of maternal and paternal chromosomes. Random distribution creates unique chromosome sets.

Flashcard 9: What is the minimum number of genetically distinct gamete types from independent assortment for $n=3$?

Answer: $2^3 = 8$. Each chromosome can orient toward either pole independently.

Flashcard 10: What are sister chromatids?

Answer: Identical copies of one chromosome joined at a centromere. Result from DNA replication before cell division.

Flashcard 11: What does diploid mean in terms of chromosome sets?

Answer: Two sets of chromosomes ($2n$). Contains chromosomes from both parents in body cells.

Flashcard 12: What is the minimum number of genetically distinct gamete types from independent assortment for $n=10$?

Answer: $2^{10} = 1024$. Ten chromosome pairs create many possible combinations.

Flashcard 13: What is the genetic result of crossing over?

Answer: Recombinant chromatids with new allele combinations. New gene combinations increase genetic variation.

Flashcard 14: Identify the phase when sister chromatids separate to opposite poles in meiosis.

Answer: Anaphase II. Individual chromatids separate like in mitosis.

Flashcard 15: What is synapsis in meiosis?

Answer: Pairing of homologous chromosomes during prophase I. Essential for crossing over and genetic recombination.

Flashcard 16: Which process directly creates recombinant chromosomes: independent assortment or crossing over?

Answer: Crossing over. Physical exchange creates new chromosome combinations.

Flashcard 17: In which division does nondisjunction occur if sister chromatids fail to separate?

Answer: Meiosis II. When sister chromatids stick together improperly.

Flashcard 18: What is synapsis in meiosis?

Answer: Pairing of homologous chromosomes during prophase I. Essential for crossing over and genetic recombination.

Flashcard 19: What is the chromosome number change in mitosis from start to finish?

Answer: Chromosome number stays the same. Diploid parent produces diploid daughter cells.

Flashcard 20: Choose the word that completes the statement: Mitosis produces cells that are usually  .

Answer: Diploid (same ploidy as the parent cell). Mitosis maintains the original chromosome number.

Flashcard 21: What does haploid mean in terms of chromosome sets?

Answer: One set of chromosomes ($n$). Found in gametes with half the chromosome number.

Flashcard 22: What is the genetic result of independent assortment?

Answer: New combinations of maternal and paternal chromosomes. Random distribution creates unique chromosome sets.

Flashcard 23: What are sister chromatids?

Answer: Identical copies of one chromosome joined at a centromere. Result from DNA replication before cell division.

Flashcard 24: Which type of cell division produces gametes in animals: mitosis or meiosis?

Answer: Meiosis. Only meiosis reduces chromosome number to create sex cells.

Flashcard 25: What is the main purpose of meiosis I?

Answer: Reduce chromosome number by separating homologs. The reductional division creating haploid cells.

Flashcard 26: Which meiosis division separates sister chromatids: meiosis I or meiosis II?

Answer: Meiosis II. Similar to mitosis, separating duplicated chromosomes.

Flashcard 27: What is crossing over?

Answer: Exchange of DNA between non-sister chromatids of homologs. Creates new allele combinations on chromosomes.

Flashcard 28: Which type of cell division is primarily used for growth and repair: mitosis or meiosis?

Answer: Mitosis. Maintains diploid chromosome number for body cell replacement.

Flashcard 29: In which meiosis phase does crossing over occur?

Answer: Prophase I. When homologs are paired and can exchange segments.

Flashcard 30: What is polyploidy?

Answer: More than two complete sets of chromosomes (e.g., $3n$). Often results from fertilization errors or nondisjunction.

Flashcard 31: What is the genetic similarity of daughter cells after mitosis?

Answer: Genetically identical to each other and the parent cell. No genetic recombination occurs during mitosis.

Flashcard 32: What are homologous chromosomes?

Answer: A maternal and paternal pair with the same genes. Carry the same genes but may have different alleles.

Flashcard 33: What is mitosis?

Answer: A one-division process producing two genetically identical cells. Maintains chromosome number for growth and tissue repair.

Flashcard 34: What is the genetic similarity of daughter cells after meiosis?

Answer: Genetically different from each other and the parent cell. Crossing over and independent assortment create variation.

Flashcard 35: What is independent assortment?

Answer: Random orientation of homologous pairs in metaphase I. Each pair aligns independently at the cell center.

Flashcard 36: Identify the immediate product of meiosis I in chromosome form.

Answer: Two haploid cells with duplicated chromosomes. Sister chromatids remain attached after first division.

Flashcard 37: What is crossing over?

Answer: Exchange of DNA between non-sister chromatids of homologs. Creates new allele combinations on chromosomes.

Flashcard 38: Identify the phase when homologous pairs line up at the cell equator in meiosis.

Answer: Metaphase I. Homologous pairs align rather than single chromosomes.

Flashcard 39: How many daughter cells does one cell produce after mitosis?

Answer: Two daughter cells. One division produces two diploid cells.

Flashcard 40: Choose the word that completes the statement: Meiosis produces cells that are  .

Answer: Haploid. Meiosis reduces chromosome number by half.

Flashcard 41: In which division does nondisjunction cause gametes with abnormal chromosome number if homologs fail to separate?

Answer: Meiosis I. When whole chromosome pairs fail to separate.

Flashcard 42: What is the chromosome number change in meiosis from start to finish?

Answer: Diploid to haploid (reduction division). Meiosis halves chromosome number from parent to gamete.

Flashcard 43: Which process shuffles whole maternal and paternal chromosomes into gametes: crossing over or independent assortment?

Answer: Independent assortment. Random distribution of intact parental chromosomes.

Flashcard 44: What is the term for cells produced by meiosis in animals?

Answer: Gametes (sperm and eggs). Haploid reproductive cells for sexual reproduction.

Flashcard 45: Identify the phase when homologous chromosomes separate to opposite poles in meiosis.

Answer: Anaphase I. Whole chromosomes move, not individual chromatids.

Flashcard 46: Which process directly creates recombinant chromosomes: independent assortment or crossing over?

Answer: Crossing over. Physical exchange creates new chromosome combinations.

Flashcard 47: What is nondisjunction?

Answer: Failure of homologs or chromatids to separate properly. Results in gametes with wrong chromosome numbers.

Flashcard 48: What is a tetrad (bivalent) in meiosis?

Answer: Paired homologous chromosomes with four chromatids total. Forms when homologs pair during prophase I.

Flashcard 49: Which meiosis division separates sister chromatids: meiosis I or meiosis II?

Answer: Meiosis II. Similar to mitosis, separating duplicated chromosomes.

Flashcard 50: How many daughter cells does one diploid cell produce after meiosis?

Answer: Four haploid daughter cells. Two divisions after one DNA replication cycle.

Flashcard 51: Identify the phase when sister chromatids separate to opposite poles in meiosis.

Answer: Anaphase II. Individual chromatids separate like in mitosis.

Flashcard 52: What is the minimum number of genetically distinct gamete types from independent assortment for $n=10$?

Answer: $2^{10} = 1024$. Ten chromosome pairs create many possible combinations.

Flashcard 53: In which meiosis phase does independent assortment occur?

Answer: Metaphase I. When chromosome pairs randomly orient before separation.

Flashcard 54: Which process includes two nuclear divisions: mitosis or meiosis?

Answer: Meiosis. Two sequential divisions create four cells.

Flashcard 55: In which meiosis phase does crossing over occur?

Answer: Prophase I. When homologs are paired and can exchange segments.

Flashcard 56: How many daughter cells does one cell produce after mitosis?

Answer: Two daughter cells. One division produces two diploid cells.

Flashcard 57: What are homologous chromosomes?

Answer: A maternal and paternal pair with the same genes. Carry the same genes but may have different alleles.

Flashcard 58: In which division does nondisjunction occur if sister chromatids fail to separate?

Answer: Meiosis II. When sister chromatids stick together improperly.

Flashcard 59: What is meiosis?

Answer: A two-division process producing four haploid gametes. This reduction division creates sex cells for reproduction.

Flashcard 60: What is the main purpose of meiosis II?

Answer: Separate sister chromatids to form haploid cells. The equational division like mitosis.

Flashcard 61: How many rounds of DNA replication occur before meiosis I and II?

Answer: One round of DNA replication. DNA copies once but cell divides twice.

Flashcard 62: In which meiosis phase does independent assortment occur?

Answer: Metaphase I. When chromosome pairs randomly orient before separation.

Flashcard 63: Identify the immediate product of meiosis I in chromosome form.

Answer: Two haploid cells with duplicated chromosomes. Sister chromatids remain attached after first division.

Flashcard 64: Identify the immediate product of meiosis II in chromosome form.

Answer: Four haploid cells with unduplicated chromosomes. Sister chromatids separate in the second division.

Flashcard 65: Which meiosis division separates homologous chromosomes: meiosis I or meiosis II?

Answer: Meiosis I. Reduces chromosome number by half in first division.

Flashcard 66: What is fertilization's main contribution to genetic diversity?

Answer: Random fusion of two genetically unique gametes. Combines genetic material from two different parents.

Flashcard 67: Identify the phase when homologous pairs line up at the cell equator in meiosis.

Answer: Metaphase I. Homologous pairs align rather than single chromosomes.

Flashcard 68: How many daughter cells does one diploid cell produce after meiosis?

Answer: Four haploid daughter cells. Two divisions after one DNA replication cycle.

Flashcard 69: Which meiosis division separates homologous chromosomes: meiosis I or meiosis II?

Answer: Meiosis I. Reduces chromosome number by half in first division.

Flashcard 70: What is the term for cells produced by meiosis in animals?

Answer: Gametes (sperm and eggs). Haploid reproductive cells for sexual reproduction.

Flashcard 71: What is the minimum number of genetically distinct gamete types from independent assortment for $n=3$?

Answer: $2^3 = 8$. Each chromosome can orient toward either pole independently.

Flashcard 72: What is the key difference between metaphase of mitosis and metaphase I of meiosis?

Answer: Mitosis: single chromosomes; meiosis I: homologous pairs. Alignment differs because homologs pair in meiosis.

Flashcard 73: In which division does nondisjunction cause gametes with abnormal chromosome number if homologs fail to separate?

Answer: Meiosis I. When whole chromosome pairs fail to separate.

Flashcard 74: What is the key difference between anaphase of mitosis and anaphase I of meiosis?

Answer: Mitosis: chromatids split; meiosis I: homologs separate. Chromosome separation mechanisms differ between divisions.

Flashcard 75: What is the genetic similarity of daughter cells after mitosis?

Answer: Genetically identical to each other and the parent cell. No genetic recombination occurs during mitosis.

Flashcard 76: What is the key difference between metaphase of mitosis and metaphase I of meiosis?

Answer: Mitosis: single chromosomes; meiosis I: homologous pairs. Alignment differs because homologs pair in meiosis.

Flashcard 77: What is nondisjunction?

Answer: Failure of homologs or chromatids to separate properly. Results in gametes with wrong chromosome numbers.

Flashcard 78: What is the key difference between anaphase of mitosis and anaphase I of meiosis?

Answer: Mitosis: chromatids split; meiosis I: homologs separate. Chromosome separation mechanisms differ between divisions.

Flashcard 79: How many rounds of DNA replication occur before meiosis I and II?

Answer: One round of DNA replication. DNA copies once but cell divides twice.

Flashcard 80: What event must occur before meiosis begins to copy DNA?

Answer: DNA replication in S phase of interphase. Occurs before meiosis I begins, not between divisions.

Flashcard 81: What is meiosis?

Answer: A two-division process producing four haploid gametes. This reduction division creates sex cells for reproduction.

Flashcard 82: What is the main purpose of meiosis I?

Answer: Reduce chromosome number by separating homologs. The reductional division creating haploid cells.

Flashcard 83: Which type of cell division is primarily used for growth and repair: mitosis or meiosis?

Answer: Mitosis. Maintains diploid chromosome number for body cell replacement.

Flashcard 84: What is a chiasma (plural chiasmata)?

Answer: The visible site where crossing over occurs. Physical evidence of genetic material exchange.

Flashcard 85: What event must occur before meiosis begins to copy DNA?

Answer: DNA replication in S phase of interphase. Occurs before meiosis I begins, not between divisions.

Flashcard 86: What is the main purpose of meiosis II?

Answer: Separate sister chromatids to form haploid cells. The equational division like mitosis.

Flashcard 87: Which process includes two nuclear divisions: mitosis or meiosis?

Answer: Meiosis. Two sequential divisions create four cells.

Flashcard 88: What is the chromosome number change in meiosis from start to finish?

Answer: Diploid to haploid (reduction division). Meiosis halves chromosome number from parent to gamete.

Flashcard 89: What is mitosis?

Answer: A one-division process producing two genetically identical cells. Maintains chromosome number for growth and tissue repair.

Flashcard 90: Choose the word that completes the statement: Meiosis produces cells that are  .

Answer: Haploid. Meiosis reduces chromosome number by half.

Flashcard 91: What is independent assortment?

Answer: Random orientation of homologous pairs in metaphase I. Each pair aligns independently at the cell center.

Flashcard 92: Choose the word that completes the statement: Mitosis produces cells that are usually  .

Answer: Diploid (same ploidy as the parent cell). Mitosis maintains the original chromosome number.

Flashcard 93: Identify the immediate product of meiosis II in chromosome form.

Answer: Four haploid cells with unduplicated chromosomes. Sister chromatids separate in the second division.

Flashcard 94: Identify the phase when homologous chromosomes separate to opposite poles in meiosis.

Answer: Anaphase I. Whole chromosomes move, not individual chromatids.

Flashcard 95: What is the genetic similarity of daughter cells after meiosis?

Answer: Genetically different from each other and the parent cell. Crossing over and independent assortment create variation.

Flashcard 96: What is a chiasma (plural chiasmata)?

Answer: The visible site where crossing over occurs. Physical evidence of genetic material exchange.

Flashcard 97: Which type of cell division produces gametes in animals: mitosis or meiosis?

Answer: Meiosis. Only meiosis reduces chromosome number to create sex cells.

Flashcard 98: What does haploid mean in terms of chromosome sets?

Answer: One set of chromosomes ($n$). Found in gametes with half the chromosome number.