Download MT REVIEW #1

Station 1
A student was performing an experiment about the rate of photosynthesis in a certain type of algae when
it is exposed to different colors of light. Write a hypothesis for this experiment. Identify the dependent
and independent variables as well as the control and experimental group(s).
If red light is best for photosynthesis then plants grown under red light will grow the tallest.
Dependent variable (results) = height of plants (growth)
Independent variable = color of light (presence of red light).
Remember to use If/then format for writing hypothesis. If/then format allows you to communicate the
condition you will manipulate or test and what results you will collect/measure to answer your question.
Give an example of both qualitative and quantitative data that the student might collect in this
experiment.
Quantitative: heights of plants in centimeters
Qualitative: Sketches of plants or descriptions
Explain why the student expects the color of light to have an influence on the rate of photosynthesis.
Plants (chlorophyll) are green because chlorophyll reflects green wavelengths of light. This means plants do
not use green wavelengths. They absorb red and blue wavelength. Specific wavelengths are required to
activate photosystem/centers inside chloroplasts for photosynthesis.
Station 2
Identify the parts indicated on the diagram of the compound light microscope below.
Eye piece
Objective lenses
arm
stage
diaphragm
Fine adjustment
Light source
Coarse
adjustment
base
The eyepiece of the above microscope has a magnification of 10x. The low power objective is 10x and
high power is 50x. What is the total magnification at each power?
Total Magnification = Eye piece magnification x Objective Lens magnification
Low power total mag. = (10 x 10) = 100 x
High power total mag. = (10 x 50) = 500 x
Under high power, the field of view (F.O.V.) of the microscope is 750µm (micrometers). There are 1000
micrometers in a millimeter. What is the F.O.V. in millimeters?
750 um x 1 mm = 0.750 mm
1000 um
Station 3
Biology is the study of life. In order to be classified as living, a specimen must certain characteristics.
(Viruses do not have all these characteristics, which is why they are not considered living). List FIVE
characteristics shared by all living things.
1. Cellular Organization – must be made of one or more cells.
2. Reproduction – have ability to reproduce offspring independently
3. Inheritance – have an inheritance molecule (DNA/RNA) to encode and pass on traits to offspring
4. Obtain and Use Energy – Use respiration or fermentation to break down food for energy and use
energy for cell functions.
5. Homeostasis (Self-Regulation) – maintain an internal environment separate from external
environment (temperature, pH, etc.)
6. Responsiveness – respond to stimuli (movement, growth, etc.)
7. Growth and Development
8. Adaptation - Adapt through natural selection (Population evolves, NOT the individual.)
9. Metabolism – all of the chemical reactions occurring within a cell/organism.
Biology can be studied at varying levels, from as narrow as a cell to as broad as the biosphere. Fill in
the missing levels of organization (small to large) that biology is studied at.
Largest Level:
Smallest Level:
Biosphere – All ecosystems on planet
Ecosystem – Living organisms and non-living factors (abiotic: water,
oxygen, nitrogen) that they interact with in a given area.
Population – Group of the same species living in the same area.
Organism- Made of groups of specialized cells (if multicellular)
Cells – smallest unit of living organisms
Molecules – make up cells
Station 4
The pH of oven cleaner was found to be around 12. Classify this substance as an acid or base.
Strong base
Is glucose an organic molecule? Why?
Yes: It is carbon based (made of 2 or more carbon atoms) and is an important component/building
block for living organisms.
Copy and complete the following chart in your notes:
Biomolecule
Elements
Monomer
Carbohydrates
C, H, O
Monosaccharides
(1:2:1)
(glu, fru, gal)
Lipids
Proteins
Nucleic Acids
C, H, O
(hydrocarbon
chains)
C, H, O, N ,S
(sulfur in R group
side chains)
Glycerol + 3 fatty
acids (=
triglyceride)
Amino acids
Polymer
Polysaccharides
(starch, cellulose,
glycogen, chitin)
Fats, Oils, Waxes,
Steroids
(cholesterol)
Polypeptides
C, H, O, N, P
nucleotide
DNA, RNA
Function
Energy supply &
storage
Long term energy
storage; form cell
membranes
catalyze chemical
reactions, immune
response
(antibodies), form
cell membranes &
chromosomes.
Heredity; code for
traits/proteins.
Form
chromosomes
Station 5
Using your knowledge of the collision theory and enzymes, explain why there is very little activity at
5°C and 35°C.
Collisions between molecules increase as the temperature increases and molecules move faster (more
kinetic energy). More collisions translate to more contact between enzymes and substrates and more
reactions are facilitated. Above 35 C enzyme activity decreases because proteins (which most
enzymes are) denature (unravel and lose shape so substrate will not fit in the active site) and lose
function. Below 5oC molecular collisions between enzyme and substrate occur very infrequently and
therefore chemical reactions that sustain life can’t occur at the proper rate to sustain life.
Most enzymes fit into what category of macromolecules?
Proteins
What is the name for the reactant(s) that an enzyme acts upon? Substrate
Station 6
Copy the following molecule onto your sheet of paper. Label the amino group and carboxyl group.
Amino group
(-NH2)
Carboxyl group
(-COOH)
The diagram below show how two amino acids can be bound together. What has to happen? What is
the name of this process?
To join molecules and build polymers from monomers, water must be removed (a –H from one
molecule and an –OH group from another. HOH = H2O). This is called DEHYDRATION
SYNTHESIS.
What is the name of the bond between the two amino acids? Peptide bond
If two amino acids were being separated (bond broken), what would have to happen? What is the
name of this process? Water must be added to the bond that is broken (a –H is added to one
molecule and an –OH to another). This is called HYDROLYSIS.
Station 7
What is the diagram below an image of? Identify the major parts and explain why the structure is
arranged in a bilayer.
Key
A. Phosphate
head (polar)
B. Fatty acid
tail (nonpolar)
C. Phospholipid
bilayer
D. Protein
channel
(facilitated
diffusion or
active
transport)
C.
A
.
B.
Complete the following chart in your notes about organelle structure and function.
D.
Station 8
Distinguish between active and passive transport and identify three examples of each.
Active: Molecules move AGAINST gradient (low  high); through protein channels; requires ATP
(energy)
Passive: Molecules move DOWN gradient (high  low); through protein channels (b/c too big or
has charge); no energy required
Account for the change shown in the diagram below.
Solute cannot move through barrier but water can. Water moves to side with more solute to dilute the
concentration on the right and bring solutions on both sides closer to equilibrium.
Prior to the movement of water, which side of the u-tube is hypertonic and which is hypotonic?
Explain.
Right side is hypertonic (more solute dissolved)
Left side is hypotonic
Describe what would happen to both an animal cell and a plant cell in each type of solution.
Solution
Hypertonic
Hypotonic
Animal
Water moves out of cell; cell
Water moves into cell; cell
shrinks (plasmolysis)
bursts (cytolysis)
Plant
Water leaves cell; plant cell
Water enters cell; Plant cell
shrinks/wilts (plasmolysis)
swells (cytolysis due to turgor
pressure); doesn’t burst b/c of
cell wall
Station 9
Photosynthesis: (In chloroplast)
Inputs: Water, Carbon dioxide, Light energy
Outputs: Oxygen and Glucose
Stages:
1. Light Reactions: (in thylakoids) Light energy used to split water into hydrogen and oxygen.
Hydrogen sent to Calvin cycle via NADP(H) and oxygen released. ATP is broken down to ADP;
energy used to build glucose from
2. Calvin Cycle: (in stroma) Bonds of carbon dioxide and hydrogen are rearranged to form glucose
with the help of energy from ATP
Light energy
CO2
H2O
NADPH
Calvin Benson
Cycle
NADP
ATP
ADP + P
O2
C6H12O6
Respiration (in Mitochondria)
Inputs: Glucose and Oxygen
Outputs: Carbon dioxide, Water, Energy (ATP)
Stages:
1. Glycolysis: (Outside mitochondria/in cytoplasm) Glucose broken down to 2 Pyruvic acid (3-C
compound) *Anaerobic
2. Krebs: (matrix of Mitochondria) 2 Pyruvic acid  CO2 and 2 ATP
3. Electron Transport Chain: (Inner membrane of mitochondria) NADH and FADH2 (carriers of H and
electrons) donate H and electrons; electrons move through electron transport chain to produce 34
ATP; oxygen accepts hydrogens to become water.
NADH
NADH
Glycolysis
Glucose
2 Pyruvic
acid
2 ATP
Krebs
E.T.C.
34 ATP +
2 ATP
Station 10
What are homologous pairs? How many homologous pairs are found in human cells?
Matching pairs of chromosomes (1 from each parent); Humans have 23 homologous pairs.
Distinguish between gametes and somatic cells. Which is haploid and which is diploid? Explain.
Gametes are sex cells (sperm and egg); they are haploid; they have half the chromosomes or 1 set of
chromosomes # 1 – 23. Somatic cells are body cells; they are DIPLOID; they contain a complete set of
chromosomes (homologous pairs of chromosomes from mother and father).
What is the process responsible for the production of haploid cells? Meiosis creates haploid cells.
What is crossing over? When does it occur and why is it significant? When identical pieces of
homologous chromosomes break and swap pieces where they cross over. It usually occurs during
Prophase I when homologous chromosomes line up and form tetrads. This swapping of chromosomal
pieces creates new combinations of genes (combinations not found in either the mother or father).
Station 11
Figure A
Figure B
Which diagram above represents mitosis (Fig. A) and which represents meiosis? Fig. B
State three pieces of evidence to support your response.
1. Figure B (meiosis) produces 4 haploid cells
2. Homologous pairs of chromosomes line up and form tetrads only in meiosis.
3. Meiosis involves 2 processes of division
4. Mitosis – one division, 2 daughter cells genetically identical to each other & the parent cell.
Both types of processes above occur in your body. When/why would each occur?
Mitosis: Diploid body cells that are replaced/renewed or repaired undergo mitosis (skin cells need
to be replaced etc.) DNA is copied and each daughter cell receives a complete copy (set of
chromosomes).
Meiosis: When gametes (sperm and egg) are made; DNA has to be copied then HALVED. Each sex
cell receives 1 set of chromosomes (not 2x of each). When sperm and egg unite in fertilization, the
diploid number is restored.
Station 12
Identify the stages of the cell cycle shown in the following diagrams.
State the event/structure designated by each label.
Mitosis
a. Anaphase: Spindle fibers contract
and sister chromatids are pulled
apart.
c.
b. Interphase: DNA is duplicated and in form
of chromatin; nuclear envelop still present;
centrioles appear and begin to separate;
nucleolus still present as a dark spot.
d.
c. Cytokinesis: Cytoplasm divided into 2 daughter cells; Nuclear membrane
has returned. DNA has uncoiled into chromatin.
d. Metaphase: Chromosomes (sister chromatids attached at centromeres) line up at the
cell’s equator. Spindle fibers connect sister chromatids to different ends of the cell.
e. Prophase: DNA in form of duplicated chromosomes (sister chromatids); nuclear envelop disappearing;
centrioles appear and begin to separate; spindle fibers grow between centrioles
f. Telophase: Chromosomes separated; nuclear envelope reappearing; daughter cells still need to
separate.
Station 13
Model DNA replication by identifying the complementary base pairs to the template strand below.
ATGCCGATCAGCCTG
Complimentary DNA bases:
TACGGCTAGTCGGAC
Now use the same template strand to model transcription.
mRNA:
ATGCCGATCAGCCTG
UACGGCUAGUCGGAC
How many codons are in the strand above? What does each codon code for? What is the name of this
process?
Codons: 8 (3 bases = 1 codon; 1 codon = 1 amino acid)
Codons code for amino acids.
Translation = process of using instructions in messenger RNA to build a protein made from amino
acids. It occurs at ribosomes and requires the assistance of tRNA molecules (with anticodons) to
retrieve amino acids and add them to the growing polypeptide chain.
Station 14
Identify the two processes being shown on the diagram above. Transcription(in nucleus) and
Translation (in cytoplasm)
Identify a codon and an anticodon. Codon: 3 base code on mRNA (complimentary to DNA);
Anticodon: 3 base code on tRNA (complimentary to mRNA).
The polypeptide chain shown contains 8 amino acids. How many codons were read to form this
polypeptide? How many nucleotides were read?
8 amino acids = 8 codons = 24 nucleotides (8 codons x 3 bases)
Station 15
Mr. and Mrs. Jones have four children. Three of them (Two boys and one girl) have attached
earlobes (recessive trait) like their father, and the other child has free earlobes like their
mother.
a. Draw a pedigree for this family using proper pedigree formatting
b.What are the genotypes of Mr. and Mrs. Jones? Mr (aa); Mrs (Aa)
c.What are the genotypes of their four children? (aa; aa; aa; Aa)
d.What are the chances that a 5th child will have the same genotype as the mother? 50%
Station 16
Red-green color blindness is an X-linked/sex linked recessive trait in humans. What is the probability
that a colorblind woman and a man with normal vision will have a colorblind daughter? Show your
work.
XB
Xb
XBXb
Xb
XBXb
Y
Y
Xb Y
Xb
No chance there will be a colorblind daughter; All daughters are carriers. All boys are colorblind.
A man with blood type A marries a woman with type B blood. What is the maximum probability that
their first child will have type O blood? 25% chance of O blood type in child.
Show your work.
A
O
B AB BO
O AO OO
Blood type A: AA or AO (only AO will produce O blood type in children)
Blood type B: BB or BO (only BO will produce O blood type in children)
Use the following key for the next problem.
T = tall
t = short
G = green
g = yellow
Two heterozygous tall, heterozygous green plants are crossed. What possible gametes are produced
by the parental plants?
TtGg x TtGg
Gametes: TG, Tg, tG, tg
Station 17
What is shown in the diagram above? Karyotype
What information can be obtained from the diagram? Genetic disorders that involve extra or missing
chromosomes (trisomies like Trisomy 21 = Downs syndrome, XO = Turners syndrome; XXX or XXY).
Identify the type of mutations shown in the diagrams below?