Lab 7

Question 1

what do nuclei of eukaryotic organisms contain

Answer 1

clusters of genes

Question 2

genes

Answer 2

units of heredity information consisting of duplicated DNA

Question 3

what is the purpose of structural proteins in chromosomes

Answer 3

organize the DNA and participate in DNA folding and condensation

Question 4

what happens to chromosomes when cells divide

Answer 4

they are duplicated and then passed on to the daughter cells

Question 5

how do single celled organisms reproduce

Answer 5

divide for reproduction

Question 6

what do multicellular organisms have to allow for reproduction

Answer 6

reproductive cells
-egg
- sperm

Question 7

somatic cells

Answer 7

divide for growth and development or replacement

Question 8

what process do somatic cells and single celled organisms go through

Answer 8

the nucleus divides by mitosis into 2 daughter cells

Question 9

through asexual reproduction and mitosis what is produced

Answer 9

a genetically identical clone

Question 10

what process do multicellular organisms go through

Answer 10

sexual reproduction and meiosis

Question 11

meiosis

Answer 11

certain cells in ovaries or testes divide twice, but the chromosomes only replicate once

Question 12

what is the result in meiosis

Answer 12

four daughter nuclei with half the number of chromosomes

Question 13

what is one of the major differences between mitosis and meiosis

Answer 13

meiosis contributes to genetic variation that is important in sexual reproduction, while mitosis creates identical clones of a cell

Question 14

what happens in both mitosis and meiosis

Answer 14

cytokinesis

Question 15

cytokinesis

Answer 15

cytoplasm divides after nuclear division

Question 16

cell cycle

Answer 16

events that take place from the beginning of one cell division to the next
- 2 phases

Question 17

what are the two major phases of the cell cycle

Answer 17

interphase and mitotic (M) phase

Question 18

M phase

Answer 18

nucleus divides in mitosis and the cytoplasm divides in cytokinesis

Question 19

diploid cell

Answer 19

2n
- four chromosomes
- two pairs of homologous chromosomes

Question 20

homologous chromosomes

Answer 20

• same length
• same centromere position
• contain genes for the same characters

Question 21

centrosome

Answer 21

granular region that contains a pair of centrioles
- organizing center for microtubules in animal cells

Question 22

sister chromatid

Answer 22

each strand of duplicated chromosomes
- identical to each other
- held together most tightly at the centromere

Question 23

what are the 5 stages of mitosis

Answer 23

prophase
prometaphase
metaphase
anaphase
telophase

Question 24

spindle

Answer 24

fibrous round structure tapering toward each end centrioles

Question 25

blastulas

Answer 25

early embryonic stage
- cells will be dividing at any given time

Question 26

what forms a diploid zygote in meiosis

Answer 26

fused nuclei

Question 27

what does a zygote develop into

Answer 27

rounded structure called perithecium
- contains structures called asci

Question 28

non-recombinants

Answer 28

produced from cells in which no crossing over occurred

Question 29

recombinants

Answer 29

asci result from cells in which crossing over has occurred
- measure of how often crossing over occurs

Question 30

map unit

Answer 30

cannot see genes, but due to relationship between distance and recombinant frequency, can describe distance of gene from centromere

Question 31

how is map distance calculated

Answer 31

taking % recombinant frequency for the asci and divide by 2
- % recombinants=map units

Question 32

what counts as one chromosome

Answer 32

when two sister chromatids still stick together

Question 33

when are haploid cells obtained in meiosis

Answer 33

at the end meiosis I