Final Exam Review - KEY
Genetics & Heredity
Vocab
 P, F1, F2 Generations: parental generation, and offspring generation
 Genotype: genetic makeup of an organism
 Phenotype: physical appearance of a trait
 Dominant: trait that can mask a recessive trait
 Recessive: trait that is not commonly seen and can be masked by a dominant trait
 Co-dominance: when the heterozygous individuals express both alleles (ex: a red flower crossed with a
white flower will make red and white speckled flowers)
 Incomplete dominance: when the heterozygous individuals expressed a mixture of both traits (ex: a parent
with curly hair and a parent with straight hair can result in offspring with wavy hair)
 Law of segregation: Law that states that alleles during gamete formation
 Pedigree: chart the shows the presence of absence of a trait according to the relationships within a family
across several generations
 Allele: one of a number of different forms of a gene
 Homozygous: having two identical alleles for a particular gene
 Heterozygous: having two different alleles for a particular gene
 Law of independent assortment: law that states that genes for different traits can segregate independently
during gamete formation
 Nondisjunction: error in meiosis in which the homologous chromosomes fail to separate properly
 Karyotype: graph of the complete diploid set of chromosomes grouped together in pairs, arranged in order
of decreasing size
 Autosome: chromosomes that are not sex chromosomes; chromosomes # 1-22
 Sex chromosome: one of the two chromosomes that determines an individual’s sex
Questions
1. Who was Mendel and what he is best known for? Mendel was an Austrian scientist that is best known for
his studies done on pea plants to explain genetics. Known as the father of genetics.
2. How was Mendel able to control fertilization with the pea plants? Mendel was able to control fertilization
with the pea plants by removing the male reproductive parts and choose with plants were able to cross.
3. If an individual is homozygous recessive for attached earlobes and the other is heterozygous for detached
earlobes, what is the probability that their offspring will have attached earlobes? The probability that their
offspring will have attached earlobes is 50%.
4. What is the difference between a monohybrid Punnett square and a dihybrid Punnett square? In a
monohybrid cross, only one gene is being crossed. With a dihybrid cross, two genes are being crossed.
5. What is the genotypic ratio for a cross between two heterozygous purple pea plants? (Purple is dominant
over white) The ratio would be 1:2:1 (1 PP : 2 Pp : 1 pp)
6. What is the phenotypic ratio for a cross between a homozygous dominant individual and a heterozygous
individual? The ratio would be 1. (100% purple)
7. What information can you attain just from looking at a pedigree? What can you see from a karyotype? A
pedigree can determine what type of dominance the gene is over generations within a family, and possibly
predict future offspring. A karyotype can tell you the sex of an individual and if there is any chromosomal
disorders.
8. Why are X-linked disorders more commonly expressed in males? X-linked disorders are usually
homozugous recessive. Males only have one X chromosomes therefore they cannot mask the trait like a
female since their X chromosome is either affected or not.
9. How is it possible for one parent with A blood and the other with B blood to have a child with O blood? If
both parents are heterozygous for A and B blood, they have a 25% chance of their offspring having O type
blood.
10. What occurs in the cells during meiosis for an individual to have a child with Down syndrome? During
meiosis, the chromosomes do not split evenly and the sex cell will have an extra copy of chromosome
number 21. This occurrence is called non-disjunction.
DNA, RNA, & Protein Synthesis
Vocab
 Franklin: scientist that used X-ray diffraction to take photos of DNA
 Watson & Crick: scientists that are credited with discovering the structure of DNA
 Chargaff: scientist that discovered the arrangement of bonding nitrogenous bases (ex: adenine=thymine,
guanine=cytosine)
 Avery: scientist that worked with bacteriophage and discovered that it is the DNA that causes infection
 DNA: nucleic acid that hold our genetic information and uses deoxyribose as the backbone
 RNA: nucleic acid that uses ribose as the sugar backbone
 mRNA: (messenger) recipe that codes for proteins
 tRNA: (transfer) brings amino acids to the ribosomes
 rRNA: (ribosomal) makes up ribosomes
 RNA Polymerase: enzyme that makes RNA from DNA template
 Transcription: synthesis of an RNA molecule from a DNA template
 Translation: process by which the sequence of bases of an mRNA is converted into the sequence of amino
acids of a protein
 Exons: expressed sequence of DNA; codes for a protein
 Introns: sequence of DNA that is not involved in coding for a protein
 Nucleotide: monomer of a DNA or RNA
 Amino acid: monomer of a protein
Questions
1. What are the three parts of a nucleotide? The three parts of a nucleotide are the sugar, phosphate group,
and nitrogenous base.
2. What is the function of DNA in organisms? The function of DNA is to store all the genetic information for
the organism.
3. List the 4 nitrogenous bases found in DNA. Adenine, guanine, thymine, cytosine
4. In DNA, which nitrogenous base bonds with adenine? Which base bonds to guanine? Adenine bonds to
thymine. Guanine bonds to cytosine.
5. In what ways does DNA differ from RNA? RNA has ribose/DNA has dexoyribose, RNA uses uracil/DNA uses
thymine, RNA is single stranded/DNA is double stranded
6. Where in the cell does transcription take place, and what is occurring during this step? Transcriptions
takes place in the nucleus and the DNA is being copied into mRNA.
7. Where in the cell does translation take place, and what is occurring during this step? Translation takes
place on a ribosome in the cytoplasm, and the mRNA is getting coded into a protein.
8. Write the mRNA sequence for the following DNA strand: TAC-AAG-CGA-ACC-TTG-ATT
AUG-UUC-GCU-UGG-AAC-UAA
9. What is the amino acid sequence for the mRNA strand you just transcribed? Met-Phe-Ala-Trp-Asn-STOP
History of Life
Vocab
 Redi: scientist that worked with flies to
 Spallanzani:
 Pasteur:
 Oparin:
 Miller & Urey:
 Radiometric dating: method for determining the age of a sample from the amount of a radioactive isotope
 Isotopes: a form of an element where there are more or less neutrons
 Ozone: atmospheric layer in which ozone gas is relatively concentrated; protects life on Earth from sun’s
UV rays
Questions
1. If the half-life of an isotope is 2,000 years, how much of the isotope would be left after 10,000 years?
1
32
2. How old is a specimen that contains ¼ of a radioactive isotope and its half-life is 1,600 years? 3,200 years
old
3. Why was Pasteur’s experiment much more accepted by scientists during his time over Spallanzani’s
experiment? Pasteur’s experiment used a curved neck flask which allowed air to flow into the flask, but not
microorganisms. His discovery and results explained that there is no vital force in the air to spark the
production of new microorganisms. His results explained that new microorganisms come from previous
microorganisms.
4. What was the overall outcome from the Miller & Urey experiment? They were able to create amino acids
and other organic materials from inorganic gases mixed with electrical current based on the atmosphere in
the early years of our planet.
5. How do scientists believe oxygen was introduced into our atmosphere? Cyanobacteria were able to
photosynthesize and create oxygen.
6. What examples of evidence are there to back up the symbiotic theory? Chloroplasts and mitochondria are
able the size of a bacterial cell, they contain their own DNA, and replicate on their own.
Evolution & Populations
Vocab
 Darwin: English naturalist that went to the Galapagos islands and constructed the theory of evolution by
means of natural selection based on his research
 Natural selection: process by which organisms that are most suited to their environment survive and
reproduce most successfully
 Artificial selection: process by which humans choose the organisms called selective breeding of plants and
animals to promote desirable traits in offspring
 Adaptation: heritable characteristic that increases an organism’s ability to survive and reproduce in an
environment
 Homologous: structures that are similar in species of common ancestry but have a different function
 Analogous: body parts that share a common function but not a common structure
 Hardy-Weinberg equilibrium: principle that states that allele frequencies in a population remain constant
unless one or more factors cause those frequencies to change
 Common ancestry: explanation of how species now have many common structures derived from each other
 Vestigial organs: structure that is inherited from ancestors but has lost much or all of its original function
 Gene flow: when there is a change in allele frequency between populations
 Geographic isolation: form of reproductive isolation in which two populations are separated by geographic
barriers such as rivers, mountains, or bodies of water, leading to form different species
 Reproductive isolation: separation of a species or population so that they no longer interbreed and evolve
into two separate species
Questions
1. What is the driving force for evolution that Darwin highlighted in his book On the Origin of Species? Darwin
explained that natural selection is the driving force for evolution.
2. How does an animal’s fitness determine whether it will survive in an environment? An animal’s fitness
determines how well they will be able to adapt and survive in an environment and reproduce.
3. What were Darwin’s findings with the finches of the Galapagos? Darwin found that the finches of the
Galapagos varied from island to island by their beaks. Depending on the food source on each island, the
finches adapted to their surroundings and eventually became different species.
4. What are the conditions necessary for Hardy-Weinberg equilibrium? The conditions for Hardy-Weinberg
equilibrium are: large population, no mutations, mating is random, no emigration/immigration, and no
natural selection.
5. What are the four pieces of evidence to support the theory of evolution? DNA, biogeography, embryology,
and fossils
6. If two organisms have very similar DNA sequences, but are of different species what can be inferred from
this information? They must have shared a common ancestor.
Biotechnology (Gene Technology)
Vocab
 Inducer: particle that will bind to the repressor and begin the reaction of transcription
 Repressor: protein that binds to the operator on the lac operon and stops RNA polymerase from attaching
 Promoter: area on the lac operon that the RNA polymerase will bind to
 Operator: are on the lac operon that the repressor binds to
 Lac operon: a combination of genes found in a prokaryotic cell that is regulated
 Restriction Enzymes: enzyme that cuts DNA at a sequence of nucleotides
 Cloning: process of creating genetically identical cells produced from a single cell
 PCR: technique used by biologists to make many copies of a particular strange of DNA
 Gel Electrophoresis: procedure used to separate and analyze DNA fragments by placing a mixture of DNA
fragments at one end of a porous gel and applying an electrical voltage to the gel
 Recombinant DNA: DNA produced by combining DNA from different sources
 VNTR: repeats of nonsense genes found in DNA that are heritage and unique to each individual
 Carcinogen: substance that is believed to cause cancer
Questions
1. What would occur if the repressor protein of an operon no longer was functional? If the repressor protein
was no longer functional, then transcription would occur continuously and not stop. This would waste
necessary energy, and the cell would make unnecessary proteins.
2. How is it possible for some plants to have a resistance to herbicides? Some organisms are genetically
modified by inserting in genes from other organisms to make them resistant to herbicides.
3. During gel electrophoresis, how is the DNA arranged and separated by the end of the procedure? The DNA
is separated by size and charge. The smaller the DNA, the farther it gets down the gel.
4. What is the goal of the Human Genome Project? Their goal is to map out all the genes on the chromosomes
and help determine cures, treatment, and causes for specific diseases.
5. In the example of Dolly being cloned, why did the clone not live up to full life expectancy? The clone did not
live the full life expectancy because the original sheep’s DNA was already 7 years old when inserted into the
egg.
6. What are the steps to cloning? Why is it important to remove the nucleus from the egg cell? First, extract an
egg cell from a female sheep. Next, remove its nucleus and fuse with a cell of the desired organism you want
to clone (to fuse the cells you need to electric shock them). Then, allow the cells to grow into an embryo
and implant the embryo into a surrogate sheep that will bring the clone to term. It is important to remove
the nucleus from the egg cell because it contains the DNA from a sheep that we do not want to clone.
7. What are the steps to PCR? How is this technology used in crime investigations? First, the DNA sample,
DNA polymerase, primers, and free nucleotides get added into the machine. Then, the DNA gets heated to
separate the strands. The samples are then cooled down and primers are added to the separated strands.
Next, DNA polymerase adds free nucleotides and creates new strands of DNA. This process gets repeated
until enough sample is made. This can be used by crime investigators if there is a small sample left at a
crime scene and then need more copies to analyze who the guilty suspect is.
8. How can results from gel electrophoresis help determine family relation? By creating a bio fingerprint from
each person, you can identify patterns of VNTR sequences between samples and determine if there is a
relation.
Ecology
Vocab
 Ecosystem: all the organisms that live in a place, together with their non-living environment
 Organism: a single living thing
 Population: group of individuals of the same species that live in the same area
 Community: assemblage of different populations that live together in a defined area
 Biome: a group of ecosystems that share similar climates and typical organisms
 Biomass: total amount of living tissue within a given trophic level
 Niche: role that an organism plays in their environment
 Habitat: area where an organism lives
 Producers: first level of the trophic level (usually plants) that create energy from the sun
 Herbivores: organisms that only eat plants
 Omnivores: organisms that eat both plants and animals
 Carnivores: organisms that eat meat
 Decomposers: organism that breaks down and obtains energy from dead organic matter
 Autotroph: organisms that make their own food
 Heterotroph: organisms that need to eat food in order to get energy
 Scavengers: animal the consumes the carcasses of other animals
Questions
1. What is the difference between a food chain and a food web? A food web is a more complex system that
consists of many food chains. A food chain only follows just one path as animals find food. ex: A hawk eats a
snake, which has eaten a frog, which has eaten a grasshopper, which has eaten grass. A food web shows the
many different paths plants and animals are connected.
2. Energy is transferred between trophic levels, what is the relationship between the two? The higher you go
up a trophic level the energy decreases.
3. What is the ultimate source of energy on Earth? The sun.
4. What is the difference between an organism’s habitat and niche? An organism’s habitat is where it lives,
and its niche is the role it plays in its environment.
5. How are nutrients put back into the Earth and allow the food web to be considered a cycle of life?
Decomposers are organisms at the top of every food chain that break down dead and decaying organisms.
They put nutrients back into the Earth for the producers.
6. Create a food chain starting with producers with the following organisms: rabbit, grass, bacteria, eagle
grass  rabbit  eagle  bacteria
Bacteria/Viruses
Vocab
 Coccus: spherical shaped prokaryote
 Bacillus: rod-shaped prokaryote
 Spirillum: spiral shaped prokaryote
 Virus: particle made of proteins, nucleic acids, and sometimes lipids that can replicate only by infecting
living cells
 Binary fission: type of asexual reproduction in which bacteria reproduce
 Peptidoglycan: protein found in bacterial cell walls
Questions
1. What are the differences between a prokaryotic cell and a eukaryotic cell? Prokaryotic cells are smaller and
do not contain a nucleus or membrane bound organelles. Eukaryotic cells are more complex, larger, and
contain a nucleus and organelles.
2. How are antibiotics used to kill bacteria in the body? Antibiotics target specific parts of a bacteria or
bacterial processes like protein synthesis. Ex: some antibiotics target peptidoglycan which is only found in
bacterial cell walls.
3. Where do phototrophic and chemoautotrophic bacteria get their energy from? Phototrophic bacteria get
energy from the sun and chemoautotrophic bacteria get energy from chemicals.
4. What type of environments do bacteria typically grow in? Bacteria usually grow in warm, dark, and moist
areas.
5. How was the bacteria lab done in class considered to be a controlled experiment? There was a control
group (distilled) water and an experimental group (different places swabbed) that all went through the
same treatment to maintain consistency. The experimental groups are compared to the control group for
analysis.