chapter 12 continued - mitosis vocab and mitosis process

Question 1

shortened, condensed dna; tightly wrapped around histone proteins

Answer 1

unduplicated chromosome

Question 2

two identical copies of a dna molecule, held together at the centromerel; looks like an X under the microscope

Answer 2

duplicated chromosome

Question 3

a section of dna that stains darker than the rest of the chromosome; point of connection on a duplicated chromosome

Answer 3

centromere

Question 4

identical halves of a duplicated chromosome

Answer 4

sister chromatids

Question 5

cell containing two complete SETS of chromosomes; 46 chromosomes in humans (dip/double)

Answer 5

diploid (2n)

Question 6

cell containing ONE set of chromosomes; 23 chromosomes in humans (hap/half)

Answer 6

haploid (n)

Question 7

a regular body cell; diploid, and with 46 chromosomes

Answer 7

somatic

Question 8

a sex cell; sperm/egg, haploid, and with 23 chromosomes in humans

Answer 8

gamete

Question 9

made of microtubules; push and pull chromosomes around during cell division

Answer 9

spindle fibers

Question 10

first diploid cell of a new organism; fusion of egg and sperm

Answer 10

zygote

Question 11

what is the purpose of mitosis?

Answer 11

to create identical diploid somatic cells, for…
- growth
- repair
- replacement

Question 12

mitosis starts with ________ and ends with ________:

Answer 12

diploid cells; twice as many identical diploid cells

Question 13

what is the order of phases for cell division (mitosis)?

Answer 13

interphase, mitosis (prophase, metaphase, anaphase, telophase), cytokinesis

Question 14

interphase

Answer 14

prep phase
cell spends 90% of it’s life cycle here
g1: cell enlarges
s: dna replication occurs
g2: organelles duplicate, prepares to split

Question 15

prophase

Answer 15

nuclear membrane and nucleolus disappear
spindle fibers and duplicated chromosomes appear
looks like ramen noodles

Question 16

metaphase

Answer 16

duplicated chromosomes move to the equator
a sister chromatid on either side of the plate
identical cells
zig-zag stitching

Question 17

cytokinesis

Answer 17

known as cleavage in animal cells, and cell plate formation in plant cells

Question 18

how does cytokinesis occur in animal cells?

Answer 18

• after mitosis is completed, the spindle begins to disassemble
• at the midpoint of the former spindle, a ring of actin and myosin filaments attached to the plasma membrane contracts
• this contractile ring pulls the cell surface inward as it shrinks
• the ring contracts until it pinches the cell in two

Question 19

how does cytokinesis occur in plant cells?

Answer 19

• the future plate of division has established before mitosis began. vesicles cluster here when mitosis ends.
• as the vesicles fuse with each other, they form a cell plate along the plane of division
• the cell plate expands outward along the plane of division, when it reaches the plasma membrane, it attaches to the membrane, partitioning the cytoplasm
• the cell plate matures as two new cell walls. these walls join with the parent cell wall, so each descendant cell becomes enclosed by its own cell wall.

Question 20

tumors

Answer 20

sometimes a checkpoint gene mutates and control over cell division is lost. cells’ uncontrollable division forms an abnormal mass called a tumor