Mitosis and meiosis compared

Grade 9 Science Worksheet

Circle the best answer.

1. Read this first

   Model body cell (model data, not to scale)

   2n = 8, drawn as 4 pairs of chromosome cards: pair 1, pair 2, pair 3 and pair 4. Each pair has 1 dark card and 1 light card.

2. 1.

   Ari follows a model body cell with 2n = 8 as it divides once by mitosis. How many chromosomes does each daughter cell have?

   • 4 chromosomes
   • 12 chromosomes
   • 8 chromosomes
   • 16 chromosomes

3. Model germ cell (model data, not to scale)

   2n = 10, drawn as 5 pairs of chromosome cards: pair 1, pair 2, pair 3, pair 4 and pair 5. Each pair has 1 dark card and 1 light card.

4. 2.

   Bo follows a model animal cell with 2n = 10 that makes egg or sperm cells by meiosis. How many chromosomes does each finished cell have?

   • 2 chromosomes
   • 5 chromosomes
   • 10 chromosomes
   • 20 chromosomes
5. 3.

   Esme follows a model cell with 2n = 4 through meiosis. What is the total number of chromosomes in all the finished cells together?

   • 16 chromosomes
   • 4 chromosomes
   • 2 chromosomes
   • 8 chromosomes

6. Use this

   Lab note (model data), 5 rows. Columns: step, result. start, 1 germ cell, 2n = 10. divisions, 2. cells made, 4. chromosomes in each new cell, 5. new cells, all different.

7. 4.

   Kira reads a lab note about a germ cell dividing. Which choice names the division and gives the reason?

   • Fertilization, because the number changed
   • Meiosis, because the number was halved
   • Mitosis, because the new cells differ from each other
   • Mitosis, because 4 cells were made

8. Use this

   Two divisions (model data), 2 rows. Columns: division, start and divisions, cells made, chromosomes in each new cell. P, 1 cell with 2n = 12, then 1 division, 2, 12. Q, 1 cell with 2n = 12, then 2 divisions in a row, 4, 6.

9. 5.

   Luz reads the table of two divisions, P and Q. Which choice names both correctly?

   • P is mitosis and Q is meiosis, because Q halves the number
   • P and Q are both meiosis, because both copy chromosomes first
   • P and Q are both mitosis, because both start with 2n = 12
   • P is meiosis and Q is mitosis, because mitosis halves the number

10. Mitosis and meiosis side by side (facts from OpenStax Biology 2e)

    step	mitosis	meiosis
    chromosomes copied before dividing	once	once
    divisions	1	2
    cells made	2	4
    chromosomes in each new cell	same as the parent	half of the parent
    new cells	identical	different from each other

11. 6.

    Milo compares the two columns of the table. Which feature do mitosis and meiosis share?

    • Both make four cells from one starting cell
    • Both cut the chromosome number to half
    • The chromosomes are copied once, before the division starts
    • Both make daughter cells identical to the parent cell
12. 7.

    Noah compares the two columns of the table. Which feature belongs to meiosis and not to mitosis?

    • One division makes two identical cells
    • The new cells have the parent's chromosome number
    • The chromosomes are copied before the division starts
    • Two divisions follow one round of copying

13. Use this

    Two ways to reproduce (facts from OpenStax Biology 2e), 2 rows. Columns: way, starting cells, how offspring begin, offspring. asexual, such as budding yeast, 1 parent, a bud forms and the nucleus divides by mitosis, match the parent. sexual, usually 2 parents, an egg cell and a sperm cell join, differ from each other and from the parents.

14. 8.

    Ren reads about a yeast cell and the bud that pinches off from it. How do their chromosomes compare?

    • They match, because the nucleus divided by meiosis
    • The bud has a mix from two parents
    • They match, because the nucleus divided by mitosis
    • The bud has half, because mitosis halves the number
15. 9.

    Tala sees plants P and Q grow from two runners of one strawberry plant. How alike are P and Q?

    • Half alike, because each took half the parent's chromosomes
    • Genetically different, because mitosis shuffles genes in each plant
    • Genetically different, because each runner started with meiosis
    • Genetically identical, because mitosis copied the parent's chromosomes
16. 10.

    Zee compares offspring in the two rows of the card. Which row's offspring vary more from each other, and why?

    • The sexual row, because meiosis and joining mix chromosomes
    • Neither row, because meiosis makes identical cells
    • The asexual row, because mitosis mixes chromosomes
    • The asexual row, because one parent passes on more genes