Unit V Study Guide
I. Label the diagram below. In addition, identify the ends of the nucleotide strands and indicate which nitrogen bases are purines and
which are pyrmidines.
II. Identify the scientist(s) described below:
_____________________________ 1. Identified DNA replication as semi-conservative
_____________________________ 2. Expert in x-ray diffraction whose photograph was used to determine DNA structure
_____________________________ 3. Conclusively identified DNA as genetic material of chromosome
_____________________________ 4. Chemically proved nitrogen base-pairing rules
_____________________________ 5. First observed transformation in bacteria
_____________________________ 6. Credited with discovering double-helix structure of DNA
_____________________________ 7. Used enzymes to prove transforming material was DNA
III. Use the following letters to label the diagram below. Each letter may be used more than once or not at all. Then complete the paragraph about
replication.
A. 5’ end of daughter strand
B. 3’ end of daughter strand
C. 5’ end of parental strand
D. 3’ end of parental strand
E. DNA polymerase
F. where DNA ligase will unite pieces
G. Okazaki fragment
DNA replication occurs in the _____________________ of eukaryotic cells during _________ phase of the cell cycle. First, the __________________
bonds between the __________________________ are split with the enzyme, ___________________________, opening the double helix at points
called __________________________________________. Another enzyme known as _________________________ makes small cuts in the DNA,
then re-joins them to alleviate twisting of the DNA ahead of the ___________________________ fork. After separation of the parental strands,
_____________________________________________ hold them apart to prevent the __________________ bonds from re-forming. The enzyme,
_______________________________________ then moves in nucleotides according to ____________________ rules, _____________ with
________________ and ___________________ with ____________________. Nucleotides can only be added to an existing strand of nucleotides, so
first the enzyme, __________________ adds a short ____________________ at the point where replication begins. Synthesis always occurs in a
_______ to _________ direction, so one new strand is synthesized continuously producing the ___________________ strand; however the other strand
is forming away from the _______________________________ fork. This strand is known as the _____________________ strand and it is
synthesized in short pieces known as ______________________________________________. The fragments are then joined together by the enzyme,
___________________________ to form a continuous strand of nucleotides. Another ___________________________________ follows and
proofreads the newly synthesized strand of nucleotides. Each time replication takes place, a small portion of DNA is left unreplicated due to
______________________________________________________________________________; thus, a small, single-stranded segment of DNA is lost
at the ______’ end of each newly-synthesized strand with each cell cycle. The integrity of the genetic material is preserved by sequences of non-coding
nucleotides at the tips of chromosomes known as ___________________________. As cells divide, the tips shorten, leading to cell ________________
and eventually, __________________________. Two types of human cells, __________________________ and _____________________________
produce an enzyme known as ________________________________ that lengthen the non-coding tips, essentially making these cells capable of
unlimited cell division.
IV. Vocabulary Check – Each choice is used one time.
________ 1. Portion of DNA; codes for a trait
________ 2. Another name for body cells
________ 3. Term used to describe paired homologues in prophase I
________ 4. Asexual reproduction in prokaryotic cells
________ 5. Division of cytoplasm in eukaryotic cell division
________ 6. Term used to describe any cell with homologous pairs; 2n
________ 7. Attachment site on chromosome for spindle fibers
________ 8. Composition of spindle fibers
________ 9. Term used to describe fine strands of DNA & associated proteins seen during interphase
________ 10. Specific phase of cell cycle in which DNA replicates
________ 11. Structures found only in animal cells; play a role in division of DNA
________ 12. Mass of abnormal cells resulting from uncontrolled growth
________ 13. Photograph of chromosome pairs; used to diagnose chromosomal number disorders
________ 14. Location of a gene on a chromosome
________ 15. Longest portion of eukaryotic cell cycle; composed of G1, S, G2
________ 16. Location where sister chromatids are held together; point of closest contact
________ 17. Term used to describe phase of cell cycle maintained by non-dividing cells
________ 18. Enzyme-protein complex that regulates timing of cell cycle
________ 19. Process characterized by 2 cell divisions; produces egg, sperm cells
________ 20. Term used to describe exchange of genetic information that occurs in prophase I
________ 21. Region in eukaryotic cells that produces spindle fiber apparatus
________ 22. DNA and protein complex; humans have 46 in nucleus of body cells
________ 23. Portion of eukaryotic cell cycle in which cell is actively growing, metabolizing
________ 24. Pinching in of cell membrane seen in animal cells during late telophase
________ 25. Egg or sperm cell
________ 26. Identical strands of DNA
________ 27. Period of cell cycle in which a cell prepares to divide, centrioles replicate
________ 28. Construction of this occurs in cytokinesis in plant cells
________ 29. Asexual reproduction in eukaryotic cells
________ 30. Term used to describe cells with a single set of chromosomes; n
________ 31. Failure of chromosomes to separate correctly in meiosis, mitosis
________ 32. Pair of chromosomes containing same genes
________ 33. Spread of cancer cells through circulatory, lymphatic system
________ 34. Site of exchange of genetic information in crossing over
________ 35. Any chromosome other than X and Y
________ 36. Genetic make-up of an organism
________ 37. Ability of bacteria to take up genetic material from environment
________ 38. Microfilaments used to produce cleavage furrow
________ 39. Proteins that hold sister chromatids, tetrads together
________ 40. Different versions of a gene
V. Each diagram below represents the DNA content in a cell:
 One diagram shows the changes in the DNA content in a germ cell undergoing a meiosis
 One diagram follows the DNA content in a somatic cell during the mitotic cell cycle
1.
2.
3.
4.
Which letter represents G2 in a somatic cell?
Which letter(s) represents separation of homologous pairs?
Which letter(s) represents separation of sister chromatids?
In both diagrams, which letter(s) represents time periods in which the cell is haploid?
A. actin
B. allele
C. autosome
D. binary fission
E. cell plate
F. centrioles
G. centromere
H. centrosome
I. chiasmata
J. chromatids
K. chromatin
L. chromosome
M. cleavage furrow
N. cohesins
O. crossing over
P. cyclin-dependent kinase
Q. cytokinesis
R. diploid
S. G0
T. G1
U. G2
V. gamete
W. gene
X. genome
Y. haploid
Z. homologous
AA. interphase
BB. karyotype
CC. kinetochore
DD. locus
EE. meiosis
FF. metastasis
GG. microtubules
HH. mitosis
II. nondisjunction
JJ. S
KK. somatic
LL. tetrad
MM. transformation
NN. tumor
VI. Chromosome Number - For a cell in which 2n = 4, provide the correct answers to the questions below.
1. How many chromosomes in the cell in prophase of mitosis?
2. How many chromosomes in the cell in prophase I of meiosis?
3. How many chromosomes in a cell in prophase II of meiosis (assuming cytokinesis is complete after meiosis I)?
4. How many chromatids in a cell in prophase of mitosis?
5. How many chromatids in a cell in prophase I of meiosis?
6. How many chromatids in a cell in prophase II of meiosis?
7. How many chromosomes in each cell produced from mitosis?
8. How many total cells are produced from the original cell in mitosis?
9. How many chromosomes in each cell produced from meiosis?
10. How many total cells are produced from the original cell in meiosis?
VII. Identification - The diagrams below show cells in various phases of mitosis and meiosis. If 2n = 4, identify the phase of mitosis or meiosis
represented by each cell.
VIII. A COMPARISON OF MITOSIS AND MEIOSIS
IX. CELL CYCLE CONTROL
Identify the checkpoint (G1, G2, or M) primarily associated with each of the following factors:
 Density-dependent inhibition
 Alignment of sister chromatids at metaphase plate
 Proper replication of DNA
 Presence of growth factors
 Integrity of spindle apparatus
 Nutrient availability
 Damage to DNA
 Anchorage dependence
 Cell Size