Name _________________________________ Date ____________________ Period ________
EOCT Biology Review Packet
2010-2011
Enjoy your break, but do not forget you will be taking the Biology End of Course
Test (EOCT) 3 weeks after you get back to school. The EOCT is worth 15% of
your final grade for the course, and is a requirement for graduation. To ensure that
you are ready to achieve at least 80% mastery on the core concepts, I am expecting
you to complete this review packet over Spring Break.
This packet is due back when you return to school on Monday, April 11th. This
review packet will be considered ONE LAB GRADE. It is worth a total of 100
points.
To receive full credit, you must complete the entire packet, including the
justification boxes.
All the information necessary to answer the questions can be found in your biology
text and/or guided notes. You can also email me at turgeonm@fultonschools.org if
you have any questions. There are no excuses for not finishing the review
packet.
Have a wonderful break,
Mr. Turgeon
Name _________________________________ Date ____________________ Period ________
1. Organelles (SB1a)
All cells have organelles that perform specific jobs in the cell:
1. The plasma membrane (AKA cell membrane) is the boundary between the inside
and outside of the cell. It keeps the good stuff in and the bad stuff out.
2. The cell wall provides structure and protection for the cell. It is found only in
plants.
3. The cytoplasm (AKA cytosol or endoplasm) is the jellylike material that makes up
the background of the cell (between the nucleus and plasma membrane).
4. Mitochondria are the powerhouses of the cell. They are the sites of cellular
respiration.
5. Chloroplasts capture energy from the sun through the process of photosynthesis.
6. The nucleus is the control center of the cell. It contains DNA.
7. Ribosomes make (synthesize) proteins.
8. Vacuoles store materials, such as water, food and waste.
1. Label organelles I, II, III and IV on the cell to the right
1:
2:
3:
4:
2. Write the functions of the following organelles:
vacuoles:
mitochondria:
chloroplasts:
nucleus:
ribosome:
plasma membrane:
cell wall:
3. A scientist treats a cell with a chemical that destroys the ribosomes. As a result,
which cell process will be stopped?
Justification:
A. osmosis
C. photosynthesis
B. protein synthesis
D. respiration
4. Which is the most likely function of a group of cells that contains a high number
of mitochondria?
A. respiration
C. fermentation
Justification:
B. transpiration
D. photosynthesis
5. Which is the most likely function of a group of cells that contains a high number
of chloroplasts?
A. respiration
C. fermentation
Justification:
B. transpiration
D. photosynthesis
Name _________________________________ Date ____________________ Period ________
2. Diffusion, Osmosis & Active Transport (SB1d)

Diffusion is the movement of molecules to the side of a membrane that is less crowded
(has a lower concentration). Diffusion happens without energy.

Osmosis is the movement of water to the side of a membrane that has more molecules
(has a higher concentration of molecules). Because the water adds more space, it
makes the molecules less crowded. Osmosis happens without energy.

Active transport is when molecules move to the side of the membrane that is more
crowded (has a higher concentration of molecules). Active transport requires energy.
1. Which type of transport requires energy?
2. In which type of transport does water move?
Osmosis
Diffusion
Active Transport
What moves
Energy?
Toward which side?
3. In which type of transport do molecules move to the less concentrated side?
4. In which type of transport do molecules move to the more concentrated side?
5. In which direction does water move in osmosis?
If an animal cell is placed in distilled water, water will move into the cell, causing the cell to
swell and burst. The bursting of the cell is a result of which biological process?
A.
active transport
B.
enzyme activity
Justification:
C.
osmosis
D.
diffusion
A cell is observed to have no sugar inside when it is placed into a concentrated sugar
solution. After 10 minutes, there is sugar inside the cell. How did the sugar get into the
cell?
A.
active transport
Justification:
B.
enzyme activity
C.
osmosis
D.
diffusion
Name _________________________________ Date ____________________ Period ________
3. Organic molecules (SB1c)
Part 1: Write the organic molecule that is related to each of the following word:
Biomolecule
Carbohydrate
Protein
Nucleic Acid
Lipid
Monomer
Monosaccharide
Amino acid
Nucleotide
Fatty acid
Purpose
Energy
Work of the cell
Genetic
information
Makes the plasma
membrane
Examples
Sugar, starch,
cellulose, glucose
Enzyme, insulin
DNA, RNA
Fat, oil, wax
Test indicator
1.Iodine - starch
2.Benedicts sugar
Biruets
None
Brown paper bag
fatty acid nucleotide –
DNA –
enzyme nucleic acid -
energy plasma membrane amino acid glucose brown paper bag -
1. Which is the primary function of carbohydrates?
A. Storage of energy
B. Transmission of genetic material
C. Acceleration of chemical reactions
D. Transport of molecules across membranes
starch monosaccharide fat nucleus –
iodine –
Justification:
2. Which biomolecule makes up the plasma membrane?
A. Carbohydrates
C. Amino acids
B. Lipids
D. Proteins
Justification:
3. What is the main function of lipids?
A. to make the boundaries of the cell
B. to provide an immediate source of energy
C. to do the work of the cell
D. to carry genetic information
Justification:
4. Which organic compound is produced when three fatty acid molecules bond to one
glycerol molecule?
A. glycogen
B. PGAL
C. ATP D. a lipid
Justification:
Name _________________________________ Date ____________________ Period ________
4. Photosynthesis and Cellular Respiration (SB3a)
Photosynthesis: Plants (producers) can produce sugar (also called glucose) from sunlight
through a process called photosynthesis. In photosynthesis, water (H2O) and carbon dioxide
(CO2) are reactants (they go in), and sugar (C6H12O6) and oxygen (O2) are products (they come
out).
sunlight + H2O + CO2
sugar + O2
Photosynthesis is done in the chloroplast (an organelle found only in plants).
Cellular respiration: The sugar produced by photosynthesis provides energy, but our cells
cannot use the energy in sugar. It must be made into ATP (the molecule that is ALL
USABLE ENERGY). Plants and animals change sugar into ATP through a process called
cellular respiration. The equation for respiration is the OPPOSITE of the equation for
photosynthesis:
sugar + O2
H2O + CO2 + ATP
Cellular respiration is done in the mitochondria (called the powerhouse of the cell
because it makes ATP, usable energy).
Classify the following as describing photosynthesis or cellular respiration:
1. makes sugar from sunlight __________________________________________
2. converts sugar to ATP ________________________________________________
3. produces sugar and oxygen ____________________________________________
4. produces carbon dioxide and water ______________________________________
5. performed in the mitochondria _________________________________________
6. performed in the chloroplast ___________________________________________
1. Without looking at the top, write the FULL EQUATION for photosynthesis:
2. Without looking at the top, write the FULL EQUATION for respiration:
What is the relationship between the equations for photosynthesis and respiration?
A. They are the same.
B. The products of Respiration are the same as the products of photosynthesis.
C. The reactants of respiration are the same as the reactants of photosynthesis.
D. They are the reverse of each other.
The organelle that converts glucose to ATP is the:
A. Mitochondria
B. Chloroplast
C. centriole
D. nucleus
Which biological process can remove CO2 from the atmosphere and make sugars?
A. cellular respiration
C. photosynthesis
B. metabolism
D. digestion
Sugar + O2  CO2 + H2O + ATP represents the process of:
A. Photosynthesis
C. Fermentation
B. Cellular respiration
D. Glycolysis
Name _________________________________ Date ____________________ Period ________
5. Aerobic vs. Anaerobic Respiration (SB3a)
Cellular respiration is how plants and animals convert sugar to ATP (usable energy). It requires
oxygen (remember that respiration is: sugar + O2
H2O + CO2 + ATP), but when
there is no oxygen, organisms can use anaerobic respiration.
There are 2 kinds of cellular respiration: aerobic (with oxygen) and anaerobic (without
oxygen). Aerobic respiration makes 36 ATP, while anaerobic only makes 2 ATP, so aerobic
respiration makes more ATP (is more efficient). Aerobic respiration is performed in the
mitochondria, and anaerobic respiration is performed in the cytoplasm (background of the cell).
Most plants and animals do aerobic respiration, and yeast and bacteria do anaerobic
respiration.
There are 2 types of anaerobic respiration. In lactic acid fermentation, lactic acid is produced. In
alcoholic fermentation, alcohol is produced.
Complete the following chart:
Aerobic respiration
With
yes
oxygen?
ATP
produced
Example
Plants and animals
organisms
location
Anaerobic respiration
2
cytoplasm
When ATP is produced without oxygen, _________ respiration is taking place.
A. Aerobic
C. Cyclic
B. Anaerobic
D. Pyruvic
Which organism is most likely to use anaerobic respiration?
A. flower
B. tree
C. yeast
D. bird
A species of bacteria produces lactic acid and 2 ATP. What process was the bacteria
performing?
A. photosynthesis
C. transpiration
B. aerobic respiration
D. anaerobic respiration
Which statement best distinguishes aerobic from anaerobic respiration?
A. only aerobic respiration involves fermentation
B. only anaerobic respiration occurs in the mitochondria
C. only aerobic respiration requires oxygen
D. only anaerobic respiration produces carbon dioxide
In terms of ATP production, which process results in the most total energy?
A. aerobic respiration
C. fermentation
B. anaerobic respiration
D. all processes result in the same amount of energy
Name _________________________________ Date ____________________ Period ________
6. Enzymes (SB1b)
Enzymes are proteins that speed up chemical reactions in organisms. In other words, enzymes
are biological catalysts. Without enzymes to catalyze them, most reactions in the body would
happen at a very slow rate, so enzymes are necessary for reactions to happen as they do.
Enzymes usually end in “–ase.” Some examples of enzymes include lactase, catalase, and lipase.
Enzymes are re-usable. That means that they are not used up or changed in their reaction, so
they can be reused over and over again.
Enzymes are also specific. That means that they only act on one substrate (the term for the
molecule that an enzyme acts on). The enzyme and the substrate fit together like a lock and a
key.
Enzymes can be destroyed (called denatured) by 2 factors: low pH (acid) and high temperature.
When an enzyme is denatured, it no longer works to speed up a reaction.
1. What organic molecule are enzymes?
A. lipids
B. proteins
C. nucleic acids
D. carbohydrates
2. What is the term for the substance an enzyme acts on?
A. complex
B. substrate
C. enzyme
D. lipid
3. Explain what it means to say that enzymes are specific:
4. Explain what it means to say that enzymes are reusable:
5. What happens if an enzyme is put in low pH?
A. it works faster
B. it is denatured
C. it grows bigger
D. it grows smaller
6. Lactase speeds up the break-down of lactose. Which term best describes lactase?
A. substrate
B. complex
C. enzyme
D. lipid
Name _________________________________ Date ____________________ Period ________
7. Mitosis & Meiosis (SB1a, SB2c)
There are 2 ways to reproduce: asexual reproduction and sexual reproduction. In asexual
reproduction (reproduction with 1 parent), a unicellular (1-celled) organism divides in half to
make 2 identical copies of itself. This process is called mitosis. Mitosis does not lead to any
variation, because the cells it produces (called “daughter cells”) are the same as the parent cell.
In mitosis, the parent cells and the daughter cells are both diploid (meaning there are 2 copies of
each chromosome). Mitosis is also done by our body cells to allow us to grow or repair injuries.
In sexual reproduction (reproduction with 2 parents), egg and sperm (called gametes) from 2
parents join to form a new organism. Sexual reproduction does lead to variation. The egg and
sperm are created by a process called meiosis. In meiosis, the parent cell divides 2 times to
create 4 haploid (1 copy of each chromosome) daughter cells.
Complete the following chart:
Mitosis
Meiosis
Sexual or
Asexual?
Diploid or
haploid cells
formed?
Number of
divisions
Number of
cells
produced
Variation or
stability?
1. If a body cell of a certain organism contains 16 chromosomes, what is the number of
chromosomes in the organism’s egg cell?
A. 4
B. 8
C. 16
D. 32
2. The daughter cells resulting from meiosis are called?
A. gametes
B. zygotes
C. diploid cells
D. body cells
3. Which term best describes the type of cell divisions in which parent cells produce
haploid gametes?
A. mitosis
B. meiosis
C. spermatogenesis
D. oogenesis
4. Which of the following best happens to the chromosome number when a cell goes
through meiosis to become a gamete?
A. it doubles
B. it cuts in half
C. it remains the same
D. it becomes 1
5. How many chromosomes are in a typical human gamete?
A. 10
B. 46
C. 23
D. 1
6. How many chromosomes are in a typical human body cell?
A. 10
B. 46
C. 2
D. 2
Name _________________________________ Date ____________________ Period ________
8. Transcription & Translation I (SB2b)
Our DNA determines who we are because it codes for proteins (which determine our traits).
DNA is stored in the nucleus and proteins synthesized on the ribosomes (which are found in the
cytoplasm—the watery fluid outside the nucleus).
DNA needs a way to get out of the nucleus. To make this happen, DNA is first copied to mRNA
(messenger RNA). This process is called transcription. mRNA is made with complimentary
base pairs:
DNA
C
G
T
A
mRNA
G
C
A
U
The mRNA leaves the nucleus and goes to the ribosome. There, it is used to make proteins.
This process is called translation. A set of 3 base pairs (a codon) in the mRNA codes for an
amino acid (the monomer/building block of proteins). In translation, tRNA brings the
appropriate amino acid to the ribosome. rRNA (ribosomal RNA) makes up the ribosome.
Complete the following chart:
What is the function of tRNA?
A. carry amino acids to the ribosome
B. transcribe DNA
C. bring a message to the ribosome
D. carry ribosomes to the nucleus
The process by which mRNA is used to make proteins is called what?
A. traction
C. transcription
B. translation
D. codon
Proteins are made of which monomer?
A. fatty acids
B. nucleic acids
What is the product of transcription?
A. RNA
B. DNA
C. amino acids
D. monosaccharides
C. ribosomes
D. proteins
Name _________________________________ Date ____________________ Period ________
8.1 Transcription/Translation II (SB2b)
3 types of RNA: mRNA, rRNA, tRNA

mRNA (messenger RNA): brings DNA information to the cytoplasm

rRNA (ribosomal RNA): in ribosomes, helps to place amino acids in order

tRNA (transfer RNA): transports amino acids to ribosome.
Transcription: the process by which an RNA copy is made from a strand of DNA

An mRNA (messenger RNA) transcript is made during the process of transcription

Transcription is similar to DNA replication except a single stranded mRNA is made

Only one copy of mRNA is made from each DNA strand
Translation: is the process of converting the information in a sequence of nitrogen bases in
mRNA into a sequence of amino acids that make up a protein is known as translation.
1. Transcription occurs in the _________; translation occurs in the ____________.
2. The process of making RNA from DNA is called ___________________ and it occurs in the
___________________
3. The process of assembling a protein from RNA is called _________________ and it occurs in
the _____________________
4. What is the purpose of transcription?
A. to replicate DNA strands
B. to make copies of mRNA
C. to bring the amino acids together to form the protein
D. to copy a section of DNA
Name _________________________________ Date ____________________ Period ________
9. Genetic Technology (SB2f)
The human genome project, gel electrophoresis, transgenic organisms, and genetically
modified organisms are all examples of DNA technology used in the 21st century to study
genetics and its impact on our lives.
The human genome project: Your genome is the entire sequence of base pairs in your DNA.
In the human genome projects, scientists found the entire sequence of base pairs in the human
genome. This is important because it allows people’s genomes to be screened for genetic
diseases.
Gel electrophoresis: Gel electrophoresis allows scientists to take a “DNA
fingerprint” of people. This can be used to catch criminals (from DNA
left at the crime scene) or to find who a baby’s father is (paternity testing).
If the pattern of DNA from two samples is the same, the DNA belongs to
the same person (or a father and a baby). For example, in the results to
the right, the crime scene DNA pattern is the same as the pattern for suspect
C, so suspect C is the likely criminal.
Transgenic organisms: It is possible to insert one organism’s DNA into
that of another organism. One application of this is to use the DNA of
bacteria to make human insulin, a protein that people with diabetes do not
have.
The purpose of the Human Genome Project is to…
A. Insert genes of one organism into another organism’s DNA
B. Identify the sequence of base pairs in human DNA
C. Produce the first human clone
D. Create a single pedigree for every genetic disorder
Gel electrophoresis can be used to:
A. Determine if someone has a genetic disease
B. Determine the paternity of a child
C. Make insulin
D. Produce clones
Which is a use of genetically engineered bacteria?
A. identifying the remains of an unknown person
B. developing a DNA fingerprint for blood left at a crime
scene
C. making human insulin for diabetics
D. producing corn that is resistant to herbicides
DNA is obtained from a crime scene. 4 suspects are found and
their DNA is taken. Using the information at the right, which
suspect most likely committed the crime?
A. Suspect 1
C. Suspect 3
B. Suspect 2
D. Suspect 4
Name _________________________________ Date ____________________ Period ________
10. DNA & RNA structure (SB2a)
All of our genes are made up of the molecule called DNA:
deoxyribonucleic acid. DNA is a nucleic acid made up of monomers
called nucleotides. DNA has a backbone made up of phosphate
groups and deoxyribose sugar. Holding the sugar-phosphate
backbones together are nitrogenous bases (adenine, guanine,
thymine and cytosine), joined together by weak hydrogen bonds.
The structure of DNA is described as a double helix (twisted ladder).
RNA (ribonucleic acid) is another nucleic acid. There are 3 main
differences between DNA and RNA:
1. RNA has uracil (U) instead of thymine (T)
2. RNA is single stranded instead of double-stranded
3. RNA has ribose sugar, instead of deoxyribose sugar
DNA
RNA
Number of strands
Deoxyribose or ribose?
Uracil or thymine?
Which of the following are most likely part of a nucleotide of DNA?
A. uracil, ribose, guanine
B. uracil, deoxyibose, guanine
C. thymine, ribose, cytosine
D. thymine, deoxyribose, cytosine
A sugar, a phosphate group, and a nitrogen base form the building blocks of which organic
compound?
A. carbohydrates
B. lipids
C. nucleic acids
D. proteins
Which statement best describes the structure of DNA?
A. Double strand of nucleotides, contains deoxyribose
B. Double strand of nucleotides, contains ribose
C. Single strand of nucleotides, contains deoxyribose
D. Single strand of nucleotides, contains ribose
Which statement best describes the structure of RNA?
A. Double strand of nucleotides, contains deoxyribose
B. Double strand of nucleotides, contains ribose
C. Single strand of nucleotides, contains deoxyribose
D. Single strand of nucleotides, contains ribose
Name _________________________________ Date ____________________ Period ________
11. Population Ecology (SB4d)
Population growth is influenced by 2 factors: birth rate and death rate. Populations increase
when the birth rate is greater than the death rate. Populations decrease when death rate is greater
than birth rate. Populations remain the same when birth rate is the same as death rate.
Population growth can happen in 2 different rates:
 Exponential growth: the population continually increases.
 Logistic growth: the population increases, then flattens out when it
reaches its carrying capacity (the largest population the
environment can support for a long period of time).
Limiting factors are factors that limit how large the population can grow
(they determine the carrying capacity). For example, predators are a
limiting factor when they keep a population from growing larger.
____________________________________________________
______________
Write the letter of the graph to the right for the following descriptions:
1.
2.
3.
4.
5.
6.
7.
Exponential growth:
Logistic growth:
Reaches a carrying capacity:
Increases, and then predators are introduced:
No limiting factors
With limiting factors
Free of limiting factors:
A population levels out at a carrying capacity. What kind of growth was shown?
A. exponential
C. continuous
Justification:
B. negative
D. logistic
A population of deer is initially low, then grows steadily before coming to a relatively constant
population. What kind of growth is this population exhibiting?
A. linear growth
C. Logistic growth
Justification:
B. exponential growth
D. negative growth
A pond is supporting a large fish community. The addition of any more fish will cause a food shortage
that will be detrimental to the fish population. What has the pond reached?
A. biotic potential
C. carrying capacity
Justification:
B. density-dependent population
D. logistic growth
Name _________________________________ Date ____________________ Period ________
12. Symbiosis (SB4a)
There are 3 types of symbiosis: mutualism, commensalism & parasitism:
Mutualism – both organisms benefit
Commensalism– one benefits, one is not affected
Parasitism – one benefits, one is harmed
Identify the type of symbiosis:
1. A pilot fish eats scraps of food left behind from a shark. The shark is not affected.
Step 1: Figure out what 2 organisms are interacting
Organism 1:
Organism 2:
Step 2: Figure out how the organisms are being affected:
Step 3: Figure out what type of symbiosis this is:
2. Ticks live on dogs and suck their blood to get nutrition. The dogs often get sick because of
the ticks.
Step 1: Figure out what 2 organisms are interacting
Organism 1:
Organism 2:
Step 2: Figure out how the organisms are being affected:
Step 3: Figure out what type of symbiosis this is:
3. Humans benefit from bacteria that live in our intestines because they help us break down
food. Bacteria benefit because they get to eat some of the food.
4. The crab Lybia tessellata carries a pair of sea anemones on its claws. The crab uses the
sea anemone’s stinging tentacles as protection and the sea anemone obtains small food
particles released by the crab as it feeds
5. Tapeworms live in the bodies of other organisms. They use the host for food and cause
disease.
6. The Thick Knee is a type of bird that will eat parasites on the skins and teeth of the
crocodile. As a result of this relationship the Thick Knee gets food. The crocodile benefits
by having these parasites removed.
Name _________________________________ Date ____________________ Period ________
13. Plants (SB4e)
You must know the functions of the following plant parts:
Leaves – photosynthesis
Roots – absorbs water and nutrients from the soil
Xylem – transports water
Phloem – transports food
Guard cell – controls the opening and closing of the stoma
Stoma – holes in the leaf where gas exchange occurs
You must know the following types of plants:
Nonvascular = bryophytes = no xylem and phloem = moss
Gymnosperm = conifers = cones
Angiosperm = flowering plants = flowers
Write the part of the plant for each of the following functions:
Photosynthesis –
Transports nutrients –
Absorbs water from the soil –
Transports water –
Controls opening & closing of stoma –
Hole for gas exchange –
Write the type of plant (gymnosperm, angiosperm, nonvascular) for each of the following:
Cones flowers Pine tree -
moss -
Bryophyte -
conifer -
In the diagram to the right, which plant is most
likely a gymnosperm?
Key words:
A. Plant 1
B. Plant 2
C. Plant 3
D. Plant 4
In the diagram above, which plant is most likely an angiosperm?
A. Plant 1
C. Plant 3
B. Plant 2
D. Plant 4
In the diagram above, which plant is most likely a moss?
Key words:
A. Plant 1
B. Plant 3
C. Plant 2
If the xylem in a young tree is damaged, which process is first affected?
A. performing photosynthesis
C. transporting sugar to the roots
B. transporting water to the leaves
D. absorbing water from the soil
If the phloem in a young tree is damaged, which process is first affected?
A. performing photosynthesis
C. transporting sugar to the roots
B. transporting water to the leaves
D. absorbing water from the soil
D. Plant 4
Name _________________________________ Date ____________________ Period ________
14. Evolution (SB5c)
Evolution is defined as change over time. Evolution requires the following 4 components:
Variation – differences between individuals
Selection – individuals with good adaptations survive and reproduce
Inheritance – the surviving individuals pass on their genes
Time – over a long period of time, the population changes so that good adaptations are more
common
There are several other important terms:
Species – organisms that can interbreed to produce fertile offspring
Geographic isolation – a barrier separates a population (like a flood) and speciation results (the
two populations can no longer interbreed to produce viable offspring)
Biochemical evidence – compares DNA and/or proteins; this is the best evidence for evolution.
1. Penguins, bats, alligators and humans all have two bones called the radius and the ulna.
These bones have similar places and appearances in the forearm of the animal. The
similarity of these structures suggests that the organisms
A. have a common ancestor
C. evolved slowly
B. all grow at different rates
D. live for a long time
2. Natural selection states that individuals
A. that are better adapted to their environments will survive and reproduce
B. that are most simple have the greatest reproductive success
C. that share are the ones with the most mutations
D. remain unchanged over a period of time
4. Which could be considered biochemical evidence of an evolutionary relationship?
A. absence of vestigial structures
C. similar anatomical structures
B. presences of embryonic gill slits
D. presence of identical proteins
5. A volcano erupts and the lava travels through a forest separating a population of rabbits.
Over time, what will happen to the rabbits?
A. All the rabbits will look the same
C. All the rabbits will change the same way
B. The rabbits will mate with other species
D. The rabbits will become two different species
6. A person with an ear infection is given medicine to be taken for 10 days. After 4 days, he
stops taking the pills and the symptoms return. Which of the following best explains why
this occurred?
A. antibiotic resistance
C. disruptive selection
B. pesticide resistance
D. stabilizing selection
Stands for…
V
S
I
T
Means…
Name _________________________________ Date ____________________ Period ________
15. Genetics Overview (SB2c)
Genetics is the study of heredity. Heredity is defined as the passing of traits from parents to
their offspring (children). Gregor Mendel, known as the “father” of modern genetics, used
pea plants to understand how traits were passed down to successive generations.
Allele: Alternate form or version of a gene
Gene: A small segment of DNA that controls the expression of a trait (i.e. eye color)
Dominant: If present it is always expressed (seen)
Recessive: Will only be seen if no dominant alleles are present (can only be expressed with
another recessive allele)
Homozygous: Two of the same alleles (i.e. HH or hh)
Heterozygous: Two different alleles (i.e. Hh)
Punnett Squares: Used to predict possible gene combinations
Complete Dominance: One allele is completely dominant over the other
Co-dominance: Both alleles are expressed in the offspring (i.e. black cat + white cat = black &
white kittens)
Incomplete Dominance: The offspring is a mixture of both colors (i.e. red flower + white
flower = pink flowers)
1. If the gene pairs are identical, a person is called ____________________________________.
2. If the gene pairs are different, a person is called ____________________________________.
Punnett Square Practice:
1. In pea plants, green (G) is dominant to yellow (g).
A. What is the genotype of a homozygous yellow plant?
B. What is the phenotype for a plant with the genotype Gg?
C. If a homozygous green plant is crossed with a homozygous yellow plant, what
genotypes and phenotypes would you expect the F1 generation to have?
Cross: ___________ X ___________
Punnett Square:
2. In shorthorn cattle, when a red bull (RR) is crossed with a white cow (WW), all the offspring
are roan—a cow with red and white spots.
A. What type of dominance is expressed?
A. Incomplete B. Complete C. Co-dominance D. Sex-linked
B. What are the chances the offspring will be red cattle when a roan bull is crossed with a
roan cow?
Cross: ___________ X ___________
Punnett Square:
Name _________________________________ Date ____________________ Period ________
16. Genetics Extended Practice (SB2b)
Karyotype: A picture of an individual’s chromosomes.
Disorders determined by analyzing a person’s karyotype:
Down’s Syndrome: individuals carry an extra 21st chromosome (trisomy 21)
Klinefelter’s Syndrome: individuals have an extra X chromosome
Hemophilia and Color Blindness are two recessive, X-linked disorders
X-Linked Traits: genes found on the X chromosome
Multiple Alleles: traits controlled by one or more alleles of the same gene that code for a single
trait.
1. Name two disorders scientists are able to determine by examining karyotypes:
___________________________
2. XX= ______________
_____________________________
XY= ______________
3. Hemophilia is an X-linked trait. Normal clotting (H) is dominant over hemophilia (h). A
heterozygous normal (carrier) female is crossed with a male with hemophilia. What is the
genotypic and phenotypic breakdown of their offspring?
Cross: ___________ X ___________
Punnett Square:
4. List an example of a trait that has multiple alleles:
5.
Mr. A – Type A
Mrs. A – Type AB
Mr. B – Type O
Mrs. B – Type AB
Baby #1 – Type B
Baby #2 – Type AB
A. Which baby belongs to Mr. and Mrs. A?___________________
B. Which baby belongs to Mr. and Mrs. B?___________________