Download Intro to Genetics

Intro to Genetics
Matching
_____1. Chromosome
_____2. Dominant
_____3. Recessive
_____4. Homozygous
_____5. Heterozygous
_____6. Allele
_____7. Genotype
_____8. Phenotype
_____9. P1
_____10. F1
_____11. Autosome
a. Two of the same genes
b. The original homozygous parents
c. Any chromosome but the sex chromosomes
d. How the genes are expressed in an individual’s physical characteristics.
e. Always appears in the phenotype if it is found in the genotype
f. Structure found in the nucleus of a eukaryotic cell; contains genes
g. The first generation of offspring
h. A form of the gene
i. Does not appear in the phenotype if paired with a dominant gene
j. Two different genes
k. Two letters that indicate an individual’s inherited trait.
True/False
If the answer is false, change crucial information in the statement to make it true.
_____11. Rosalind Franklin discovered jumping genes.
_____12. Sex influenced traits are usually autosomal.
_____13. Height is both a polygenic and a complex character.
_____14. A somatic cell mutation is passed on to offspring.
_____15. A substitution mutation almost always leads to a frameshift.
_____16. Hemophilia is more common in boys because it is carried on the X chromosome.
Fill in the blank
Germ cells give rise to ________________________.
Which genetic trait provides protection against malaria when the individual is heterozygous?
_________________________
Which genetic disorder (that we studied) was caused by a dominant gene?
_____________________________
Which genetic disorder arises from XXY? _______________________________
Trisomy 21 is better known as _________________________________
When the environment affects the phenotype (how the genes are expressed), it is called a
___________________________________.
Short Answer
Explain what trisomies are and how they occur.
Why are frameshift mutations potentially devastating?
How are polygenic traits and multiple alleles different?
List two examples of Sex Influenced traits. How do sex-influenced traits differ from sex-linked
traits?
STRUCTURE AND FUNCTION OF THE CELL
MATCHING Write the correct letter in the blank before each numbered term.
_____1. mitochondrion
a. stores DNA
_____2. endoplasmic reticulum b. digests molecules, old organelles, and foreign substances
_____3. cell membrane
c. site of protein synthesis
_____4. ribosome
d. transport system within the cell
_____5. cell
e. packages and releases (secretes) products
_____6. Golgi apparatus
f. regulates movement of substances into and out of cell
_____7. nucleus
g. makes ATP (cellular energy) from oxygen and glucose
_____8. lysosome
h. makes glucose from light, carbon dioxide, and water
_____9. chloroplast
i. the basic unit of life
TRUE-FALSE
_____10. The nucleus is the smallest unit that can carry out all the processes of life.
_____11. The cell membrane behaves like a fluid, and the membrane’s components can move
like icebergs within it.
_____12. Cell respiration and photosynthesis are almost exactly opposite processes.
_____13. A tissue is a group of related cells that carries out a specific function.
_____14. When a solution is in equilibrium, all movement of its molecules stops.
MULTIPLE CHOICE
15. Which of the following are components of the cell membrane
a. phospholipids b. peripheral proteins c. integral proteins d. All of the above
16. In which of the following types of cells would you expect to find a large number of
mitochondria?
a. bone b. skin c. muscle d. blood
17. Sore muscles during exercise may be due to
a. a build-up of oxygen in the blood which puts pressure on muscle tissues.
b. a build-up of hydrochloric acid in the blood and low ATP production.
c. a build-up of lactic acid in the blood and low ATP production.
d. an increase in the number of mitochondria in the cells which causes them to swell.
18. Short, hairlike organelles that can move and may cover a unicellular organism or line the
respiratory tract are called
a. chromatin strands.
c. cilia.
b. flagella.
d. spindle fibers.
19. The first cells on Earth were likely
a. colonial algae.
b. eukaryotes.
c. prokaryotes that did not make their own food.
d. prokaryotes that made their own food.
20. The process of diffusion requires
a. a cell membrane.
b. an aqueous solution.
c. a difference in the concentration of molecules throughout a space.
d. All of the above
21. If the molecular concentration of a substance is the same throughout a space, the substance
a. has a large concentration gradient.
c. will undergo diffusion.
b. is in equilibrium.
d. will undergo osmosis.
22. When water moves from high to low concentration, the process is called
a. simple diffusion.
c. diffusion through ion channels.
b. facilitated diffusion.
d. osmosis.
23. What happens when a cell is placed in salt water?
a. Shrinks as water leaves.
b. Swells as water enters.
c. Stays the same as it pumps water in and out.
d. Impossible to predict.
24. All forms of passive transport depend on
a. energy from the cell in the form of ATP.
b. the kinetic energy (movement) of molecules.
c. ion channels.
d. carrier proteins.
SHORT ANSWER
25. Describe two differences between prokaryotic cells and eukaryotic cells.
26. What is homeostasis? Give an example.
27. The diagram below depicts a plant cell. Write the names of structures a–e in the blanks.
Which of these structures are found in plants but not in animals?
28. When is active transport necessary (two circumstances)? What does a cell need to use in
order to have active transport?
29. What is the correct formula for cell respiration? For photosynthesis?
30. The diagram below depicts an animal cell. Write in the names of the organelles.
Biochemistry
Matching:
_____
_____
_____
_____
_____
_____
_____
_____
Atom
Molecule
Atomic Number
Mass Number
Ion
Proton
Electron
Neutron
a.
b.
c.
d.
e.
f.
g.
h.
Positively charged; found in nucleus
Protons plus neutrons
Almost no mass; shared or traded in chemical reactions
Smallest particle of an element
More than one atom
Number of Protons
Neutral charge; mass of 1 amu
An atom with a + or - charge
True or False. Change false answers to make them true.
_____ The number of electrons can change, but the number of protons never does.
_____ Protons are shared in a covalent bond.
_____ Water is a polar covalent molecule.
_____ Hydrogen is more electronegative than oxygen.
_____ HONC includes: hydrogen, oxygen, chlorine, and nitrogen.
_____ Carbon needs four covalent bonds to be stable.
_____ Since the sodium atom has 11 protons, it is stable.
_____ Since the chlorine atom has 17 protons, it needs to gain one electron to become stable.
_____ Carbon-14 (mass of 14) has 6 protons. It must have 8 neutrons and 6 electrons.
_____ Hydrogen bonds are very strong.
_____ Cohesion is the attraction of water to itself (because it is a polar molecule).
_____ A change in pH from 2 to 4 indicates a 20-fold change in [H+] (hydrogen ion conc.).
H2O2 ----> H2O + O2
_____ What are the reactant(s) in this equation?
a. Hydrogen peroxide
b Water
c. Oxygen
_____ Catalase (made in your cells) speeds up this reaction. Catalase is a
a. Catalyst
b. enzyme
c. protein
d. both b and c
e. all of the above
_____ Within our cells, this reaction would occur _____________if a person were
experiencing hypothermia (cold body temp).
a. faster
b. slower c. It would not occur at all
What will happen to a reaction when a person has a fever over 108 degrees?
Draw a graph showing the activation energy needed for the reaction to occur without catalase.
Then, on the same graph, include a line that shows the activation energy when catalase is
present.
_____ The formation of a polysaccharide is a _______________ reaction.
a. hydrolysis
b. pH
c. dehydration synthesis
_____ The reverse process is called
a. hydrolysis
b. pH
c. dehydration synthesis
If you are looking at pictures of the biological molecules from class (carbs, lipids, etc.) and you
noticed the following detail, which molecule would you be looking at? (There may be more
than one appropriate answer for some…)
One ring:________________________________________
Several rings:_______________________________________
Nitrogen:_____________________________________________
Long hydrocarbon chain;_________________________________________
R-group:_______________________________________________
Several amino acids:_________________________________________________
Long hydrocarbon chain with only one double bond between a Carbon and an Oxygen:
________________________________________________
Peptide bonds:______________________________________________
Now, use what you’ve learned to answer questions from these scenarios:
Scenario #1: Viking Gas Exchange Experiment
In the 1970s, NASA successfully landed two spacecraft (Viking I and Viking II) on the surface
of Mars. As a part of its data collection, each lander tested for dormant life under two different
conditions. In the first test, water was added to soil samples to “awaken” dormant life forms and
then levels of gases released by the soil were measured. (The idea was that all life takes
in/releases gases (carbon dioxide, oxygen, nitrogen, methane…) and an increase in gases would
indicate that there was life in the soil sample.) The second test added nutrients (food) as well as
water to the soil sample. The gas levels were again tested.
All gas levels remained unchanged, except for oxygen (O2). After nutrients were added to one
soil sample, oxygen levels increased.
QUESTIONS
_____ What biological process on our planet (Earth) releases oxygen?
a. Cell Respiration
b. Replication
c. Photosynthesis
d. Protein Synthesis
_____If the life forms were prokaryotic, scientists would expect them to be similar to
a. bacteria.
b. viruses.
c. plant cells.
d. animal cells.
_____On Earth, animals that “eat” typically take in and release what molecules?
a. Take in carbon dioxide and oxygen; release glucose.
b. Take in carbon dioxide; release oxygen.
c. Take in oxygen; release glucose.
d. Take in oxygen and glucose; release carbon dioxide.
_____Which organelle is the location of cell respiration in plant cells?
a. golgi
b. smooth endoplasmic reticulum
c. mitochondria
d. chloroplasts
e. None. Cell respiration doesn’t happen in plant cells.
Later, some scientists questioned the results and suggested that certain chemicals in the
soil (not life forms) could release oxygen when they contact water.
What does the phrase “peer review” mean, and how is it important in science?
Scenario #2: Prenatal Testing
Denitra is an expectant mother who is seven
weeks pregnant. She and her husband,
Mario, are at the office of a genetic
counselor discussing the pros and cons of
genetic testing. Mario has a family history
of a recessive genetic disease, and he
doesn’t want to see his baby suffer with the
same disease. A blood test of Denitra has
indicated that she is a carrier of the same
disease. Denitra does not want to test the
baby saying that she will love it no matter
what the baby’s health is like.
To the right and below is a pedigree of Mario’s family.
1
Mario is represented by the square marked with an
“M”.
Who in Mario’s family has the disease?
3
a. His mother and grandfather.
b. His sister and his father.
c. His father and his brother.
d. His grandfather and his brother.
6
_____Is #1 a carrier of the disease?
a. Yes.
B. Yes
c. Impossible to tell
_____Is #3 a carrier of the disease?
a. Yes.
B. Yes
2
4
5
M
7
8
c. Impossible to tell
_____If Mario is a carrier of the disease, what percent of his sperm will carry the gene for the
disease?
a. 25% b. 50%
c. 100%
d. Varies
Refer to the Punnett Sqaure. What are the odds that their child will
carry the disease?
a. 1 in four (25%)
b. 2 in four (50%)
c. 3 in four (75%)
d. 4 in four (100%)
D
d
D DD Dd
d Dd dd
Eventually, Denita agrees to have the baby tested. In addition to testing the baby for the
presence of a protein produced by the recessive disease, the genetic counselor also prepares a
photograph of the baby’s chromosomes (a karyotype). The protein test comes back negative,
meaning the baby does NOT have the disease. However, something unexpected shows up on
the karyotype…
What is the gender of the child?
a.
Female.
b.
Male.
c.
Impossible to tell.
What is exceptional (unique) about this child’s
chromosomes?
What is the primary ethical concern with genetically
testing unborn babies?
How are the words DNA, chromosomes and genes
related?
Scenario #3: Acid Rain and Salamanders
Acid rain can increase the acidity of lakes and
ponds. In water pools of nearly neutral acidity, less
than 1 % of the salamander eggs die. In water at pH
less than 6, 60 % of the eggs die. The salamander is
particularly susceptible to acid snow melting. The
salamander breeds in early spring in temporary
ponds formed from snow melt and rain. The pH
levels may be particularly low in these ponds from
the acid shock of the freshly melted acid snow.
In the abnormal embryo (lower right), note the
swelling at the top which shows abnormal heart.
[The tail also shows abnormally slow growth.]
More than 60 % of salamanders die which develop
in waters with a pH of less than 6. Of those that do
survive, many are crippled such as this one with a
curved spine. Others also have stunted gills.
_____Where do these salamanders lay their eggs?
a. Lakes
b. ponds c. oceans
d. mountain streams
e. water “pockets” that dry up later in the season.
_____What is NOT an effect of low pH on the salamanders mentioned in the article?
a. High rates of tumors
b. Heart deformities
c. Curved spines
d. Immature gills e. Short tails
_____A scientist tried to show the impact of pH on salamander development in a laboratory
setting. What would be an appropriate control group for the experiment?
a. Salamanders raised at a pH of 6.5.
b. Salamanders raised at a pH below 6.
c. Salamanders raised at a pH of 8 or higher.
d. There is no control group for this experiment.
Describe an experiment (as above) that would test the effect of pH on salamander development.
Explain what would be manipulated (the independent variable) and what would be measured
(dependent variable).
Scenario #4: Juicy Spit Lab (yum-yum)
Draw the test tubes and contents
Background: Spit contains an enzyme called amylase.
here:
Procedure:
1. Add 1-2 mL of spit (yes, spit…) to 3 test tubes.
2. Add 2 mL of vinegar (an acid) to test tube #1
3. Boil test tube #2 for five minutes.
4. Leave test tube #3 unaltered.
5. Add 5 mL of a cornstarch-water solution to each test tube.
6. Add 5 mL of Benedict’s solution to each test tube and boil.
Test tube #3 changed to a reddish orange.
 Based on the results of test tube #3, what does amylase do?
 Predict the colors of test tubes #1 and #2 after boiling with Benedict’s solution. Explain your
reasoning.
1.
2.
 A control group is not included in the directions for this experiment. What would the control group
be? (There is more than one good answer…)