Lab chapter 8: Mitosis/Meiosis

Question 1

A cell undergoing mitosis has twenty chromosomes. How many chromosomes will each of the daughter cells have?

Answer 1

twenty each

Question 2

____ is often described as equational division

Answer 2

mitosis

Question 3

_____ is often referred to as reductional division

Answer 3

meiosis

Question 4

Counting the number of cells in interphase versus the number of cells in mitosis will allow you to

Answer 4

understand how little time a typical cell spends in completion of meiosis

Question 5

G1 is characterized by

Answer 5

rapid growth, centriole replication. of each of the interphase sections, G1 is the longest

Question 6

S phase is characterized by

Answer 6

chromosome replication, DNA synthesis

Question 7

G2 is characterized by

Answer 7

growth and final preparations for cell division

Question 8

In the absence of meiosis, fusion of an egg and a sperm would:

Answer 8

double the number of chromosomes in each cell in the offspring

Question 9

Reductive division of the nucleus is accomplished by

Answer 9

meiosis with cytokinesis occurring simultaneously

Question 10

Describe the formation of chromatids prior to mitosis

Answer 10

each chromosome in chromatin form duplicates, forming chromatids that are held together by a centromere

Question 11

True or false: chromosomes are visible in interphase

Answer 11

false they haven’t condensed yet

Question 13

During prophase, the nuclear membrane____. The chromosomes ______.

Answer 13

nuclear membrane begins to break down

chromosomes begin to coil, shorten, and become visible

Question 14

True or False: In both plant and animal cells, centrioles migrate to opposite poles during prophase

Answer 14

False, ONLY animal cells

Question 15

what are asters?

Answer 15

formed by centrioles at the end of the spindle. They play a role in cytokinesis but are not present in plant cells

Question 16

When do spindle fibers form?

Answer 16

during prophase

Question 17

Why do some chromosomes have a V shaped appearance during anaphase, while others have a check mark appearance?

Answer 17

because the chromosomes are pulled toward a pole by the spindle fibers con-nected to their centromeres

A more V like structure indicates it is a centrally located centromere

Question 18

During telophase, chromosomes _____. The nucleus and nuclear membrane ____.

Answer 18

chromosomes have arrived at poles and will lengthen and decondense

nucleus is more granular, nuclear membrane reconstructed

Question 19

Compare cytokinesis in animals versus plant cells

Answer 19

animal cells: cleavage furrow forms

plant cells: can’t form cleavage due to cell wall. They form a cell plate

Question 20

The reagants in this experiment should be handled with caution because

Answer 20

they contain strong acids

Question 21

The beaker containing the onion root tips is ___mL

Answer 21

10

Question 22

The 6N (18%) hydrochloric acid should be added to the root tips and let sit for ____

Answer 22

four minutes

Question 23

The empty HCl pipet should be placed in the _____

Answer 23

liquid waste bottle

Question 24

After the 6N 18% HCl is added to the onion roots, ____ is added and let sit for four minutes. The pipet is placed into the ____ when done

Answer 24

carnoy fixative

liquid waste bottle

Question 25

The stain used in this experiment is called

Answer 25

toluidine blue stain

Question 26

The razor should be used to cut off ___mm of the onion root tip

Answer 26

1-2

Question 27

After the root tip is placed on the center of the slide and the slide is placed on a kimwipe, the student should

Answer 27

add one drop of blue toluidine and let stain for one minute

Question 28

What is the meristematic region?

Answer 28

the area where the root tip is stained more intensely than its surroundings

Question 29

Why must the pressure of the pencil erase be applied at a perpendicular angel? What is the purpose of the pressure?

Answer 29

perpendicular or the slide will break

the pressure allows the cells of the root tip to spread out in a layer that is one cell thick

Question 30

The cell cycle of the allium root tip is about

Answer 30

16 hours

Question 31

One major difference between mitotis prophase 1 and meiotic prophase 1 is

Answer 31

late in meiotic prophase 1, homologous chromosomes synapse (pair up), and then form a tetrad where recombination occurs

Question 32

TorF: The chromosomes in metaphase II are identical

Answer 32

false because they’ve already exchanged DNA in prophase I

Question 33

The new nuclei in telophase 1 have____ as many chromosomes as the mother cell

Answer 33

half

Question 34

In anaphase 1, the chromatids will move to ___ poles

Answer 34

the same poles because they haven’t split yet, the homologous chromosomes split instead

Question 35

Define reduction division

Answer 35

division resulting in daughter cells with half the chromosome number as the mother cell
meiosis moment

Question 36

What are genes

Answer 36

regions that contain the instructions for production of RNA

Question 37

What are alleles

Answer 37

variations in genes across a population

account for differences in a given species