1. Bell Work Friday, December 15, 2017 (Add this to your Bell Work sheet
Use the diagram to answer the question that follows. Which phase of mitosis is represented in the diagram?
Prophase
Metaphase
Anaphase
Telophase
A plant cell with 12 chromosomes undergoes normal mitosis. What is the total number of chromosomes in each of the resulting daughter cells? 24 12 6 4
Which sequence of the cell cycle is correct in eukaryotes?
G1 to G2 to S to M to cytokinesis
G1 to M to G2 to S to cytokinesis
G1 to S to M to G2 to cytokinesis
G1 to S to G2 to M to cytokinesis

2. Midterm Study Guide
Fall 2017

3. 1. Define the following: independent variable, dependent variable, control vs. experimental group, and constants. Review experimental design.
Independent: The variable in an experiment that is deliberately changed by the researcher on purpose.
Dependent: The variable in an experiment that is counted or measured; changes in response to the factors changed by scientists.
Constants (Controlled variables): A variable that is held constant in order to assess or clarify the relationship between two other variables

4. 2. What are the characteristics of a good experiment (how many variables can be tested at one time)?
An experiment in which an observer tests a hypothesis by looking for changes due to an independent variable.
ONE! Only one independent variable can be tested at a time, otherwise we don’t know what is affecting the outcome (dependent variable)
Ex: A student wants to determine if a certain plant grows best in the shade or sun. He grows one in the shade and one in the sun. All other variables are controlled (remain the same): same type of soil, same amount of water, same type of plant, same space to grow

5. 3. What is the difference between accuracy and precision?
Accuracy: How close you are to the true value being measured
How to find: Compare the data to see who/what is closest to the true value (this will always be given in order to determine accuracy!)
Precision: The exactness of a measurement
How to find: Determine the differences between your different sets of data. Whoever/whatever has the smallest difference is most precise.
**whatever your units are on your measurement scale, a 1/2 unit to either side of the actual value represents the degree of accuracy**

6. 4. What are the characteristics of prokaryotes and eukaryotes?
Genetic material is NOT contained in a nucleus
Usually smaller and less complicated than euks.
NO membrane bound organelles
Example: Bacteria
Has a nucleus which keeps the DNA separated from the rest of the cell
Typically larger and more complex than proks.
Have membrane bound organelles
Examples: plants, animals, fungi

7. 5. Name the 4 differences between plant and animal cells.
Plant Cells
Animal Cells
1. Rectangular shape
2. Has a cell wall and a cell membrane
3. Has a large vacuole
4. Contains chloroplasts
1. Circular in shape
2. No cell wall, only a cell membrane
3. Vacuole is very small or non existent
4. No chloroplast

8. 6. Review the functions of the 14 cell organelles studied in class.
1. Mitochondria- Site of cell respiration, makes energy
2. Nucleus- contains all genetic information (DNA)
3. Smooth ER- makes fats
4. Rough ER- contains ribosomes
5. Ribosomes- site of protein synthesis
6. Cytoplasm- Jelly like substance that holds all the other organelles
7. Lysosome- cleans the cell
8. Cell membrane- lets certain substances in and out of the cell
9. Cell wall- provides rigid support for plant cells only
10. Chloroplast- site of photosynthesis in plants only
11. Centrioles- helps with cell reproduction
12. Vacuole- stores wastes and other materials (in plant cells)
13. Golgi Apparatus- Modifies, packages, and ships proteins in and out of the cell
14. Microtubules/Microfilaments- help with cell support

9. 7. Draw a picture of the cell membrane.

10. ATP- Adenosine triphosphate
8. Which MOLECULE is produced by mitochondria and provides energy for transport?
ATP- Adenosine triphosphate

11. DNA- deoxyribonucleic acid
9. What molecule is housed in the nucleus and provides genetic information to build proteins?
DNA- deoxyribonucleic acid

12. 10. Describe a hypertonic, hypotonic, and isotonic solution.
MORE solutes in the solution
MORE water in the cell
Water rushes OUT of the cell.
Cell shrivels and dies

13. ISOTONIC
Water moves freely back and forth across the cell membrane
Equal balance of solutes and water on both sides
Cell remains normal

14. HYPOTONIC
FEWER solutes in the solution
LESS water in the cell
Water rushes INTO the cell
Cell swells and bursts

15. This is called: Passive transport 3 Types:
11. What is it called when particles move across a membrane without energy? Name and understand the 3 types of examples of this movement.
This is called: Passive transport
3 Types:
Diffusion- movement from high to low
Facilitated diffusion- movement from high to low but with the help of a protein
Osmosis- diffusion of water

16. This is called: Active transport
12. What is it called when particles move across a membrane with energy? Also, draw a picture.
This is called: Active transport
Movement from low to high

17. 13. Name the monomers and polymers of the four organic compounds
Lipids
Proteins
Monomer- None
Monomer- Amino Acid
Polymer- fatty acid
Polymer- Polypeptide
Carbohydrates
Nucleic Acids
Monomer- Monosaccharide
Monomer- Nucleotide
Polymer- Polysaccharide
Polymer- Nucleic Acid

18. 14. Review the indicator tests
Use your chart!

19. 15. How does the enzyme increase the reaction rate?
It lowers the activation energy which means less time to get started = quicker reactions

20. 16. Graph how enzymes lower the activation energy in a cell.

21. A protein that speeds up chemical reactions. Also called a catalyst
17. What is an enzyme?
A protein that speeds up chemical reactions.
Also called a catalyst

22. 18. Identify the three components of a nucleotide
1. Phosphate 2. Sugar (DNA= deoxyribose) 3. Nitrogenous base (A,T, G, or C)

23. 19. What bases pair together in a DNA double helix?
Adenine—Thymine
Guanine—Cytosine

24. 20. What is Chargaff’s Rule
20. What is Chargaff’s Rule? Know how to find the percentages of ALL bases given ONE base.
Chargaff’s Rule:
#A= #T
#G= #C
If C= 20% of a DNA sample, what percentage does Thymine make up?
C=20 so G=20 (total of 40%)
100-40= 60 (%of A and T combined)
60÷2= 30%= T

25. 21. Write the complementary DNA sequence to the following DNA sequence: GTCACGGTAATC
CAG TGC CAT TAG ~ Complimentary

26. The order (sequence) of the bases
22. What, specifically, about the DNA molecule, causes people to have different physical traits?
The order (sequence) of the bases

27. 23. Replicate the DNA: GTCACGGTAATC
CAG TGC CAT TAG

28. 24. Transcribe and translate the DNA: GTCACGGTAATC
mRNA: CAG / UGC/ CAU/ UAG
AA: GLN/ CYS / HIS / STOP

29. 25. What occurs during DNA replication? Describe the process.
The enzyme helicase breaks the hydrogen bonds between the two strands and separates the strands. DNA Polymerse adds new nucleotides (using base pairing rules) and proofreads the new strand.

30. 26. What occurs during transcription? Describe the process.
An RNA strand is made from a DNA strand inside the nucleus

31. 27. What occurs during translation? Describe the process.
RNA leaves the nucleus and goes to the ribosome where amino acids are formed and therefore proteins. The anticodons of tRNA bind to the codons of mRNA, bringing the correct amino acid.

32. 28. What is the role of mRNA and tRNA in translation?
mRNA: gets transcribed and leaves the nucleus to go to the ribosome to produce proteins.
tRNA: matches with the correct codon and brings the correct amino acid to add to the polypeptide chain

33. 29. What is the difference between RNA and DNA?
RNA has no T but a U, while DNA has T
RNA= single strand; DNA= double strand
RNA= ribose sugar; DNA= deoxyribose sugar
RNA= can leave the nucleus; DNA= cannot leave the nucleus

34. 30. To allow living things to grow (we are NOT one big cell)
What is the purpose of mitosis?
What is the purpose of meiosis?
To allow living things to grow (we are NOT one big cell)
To replace damaged and worn out cells
To reduce the number of chromosomes (2N to N)
To create sex cells (sperm and eggs)

35. Mitosis- All cells except sex cells (somatic cells).
31. In which cells does mitosis take place? In which cells does meiosis take place?
Mitosis- All cells except sex cells (somatic cells).
Meiosis- ONLY sex cells (gametes).

36. 32. What is crossing over in meiosis? Draw a picture of what occurs.
Segments of homologous chromosomes are exchanged.

37. 33. Explain the difference between haploid and diploid.
Haploid= 1 set of chromosomes (in humans, 23 c’somes). Gametes are haploid.
Diploid= 2 sets of chromosomes (in humans, 46 c’somes. One set from mom, one set from dad). Somatic cells are diploid.

38. 34. What is different in prophase 1 of meiosis from prophase of mitosis?
There is crossing over of HOMOLOGOUS chromosomes in Prophase I of meiosis I.
There is NO crossing over in mitosis

39. 35. What is the difference between sexual and asexual reproduction?
Sexual needs two parents to reproduce (ex: humans, dogs, bears, etc.) and results in VARIATION
Asexual needs just one (ex: bacteria). These are clones. NO VARIATION

40. From the sex cells (gametes)
36. In what type of cells do genetic mutations get passed on the offspring?
From the sex cells (gametes)

41. 37. Explain the effects of non-disjunction and give two examples.
It’s the failure of chromosomes to separate correctly during anaphase I or anaphase II
Examples: Trisomy 21 (Down Syndrome) or Turner Syndrome (XXX) or Kleinfelter Syndrome (XXY)

42. 38. Do autosomal mutations affect offspring?No

43. Yes. This random separation helps lead to variation!
39. When homologous chromosomes separate during anaphase, is it random?
Yes. This random separation helps lead to variation!

44. n= 18 (n= haploid= sex cells) 2n=36 (2n= diploid= somatic cells)
40. If a snake has 18 chromosomes in their sex cells, how many chromosomes are in the autosomal cells? 36
n= 18 (n= haploid= sex cells)
2n=36 (2n= diploid= somatic cells)

45. 41. What is the total number of cells after meiosis?
4 haploid

46. 42. Why is crossing over so important?
It leads to genetic variation.
Variety in nature is a good thing!

47. 43. List the three types of point/gene mutations.
1. Substitution- Exchanging one base for another 2. Insertion- Adding one base 3. Deletion- Removing one base

48. 44. List the four types of chromosome mutations.
1. Deletion- Deleting one or more genes
2. Inversion- Flipping around a gene segment (ex: ABCDEF  ABEDCF)
3. Duplication- Copying a gene or genes
4. Translocation- When genes of a chromosome break off and reattach to a non-homologous chromosome.

49. Happens with Insertions and Deletions
45. What is a frameshift mutation? Which types of mutations cause frameshifts?
A frameshift mutation changes the reading frame of the DNA sequence. All of the codons, and therefore, amino acids AFTER the mutation will be different
Happens with Insertions and Deletions