Download DNA --- mRNA--- tRNA--- amino acids--

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Biology 1 Final Exam Review
Period_____
1. Defined diploid and haploid. If an organism has a haploid number of 20, what is the
diploid number?
(A) (A) Having the same number of sets of chromosomes as a germ cell, or half
the diploid number of a somatic cell. The haploid number (23 in humans) is the normal
chromosome complement of germ cells. If haploid number of 20, diploid number of 40.
2. Define mitosis and meiosis. What is mitosis for, and what is meiosis for?
(A) Cells divide and reproduce in two ways: mitosis and meiosis.
Mitosis is a process of cell division that results in two genetically identical daughter cells
developing from a single parent cell. ... Mitosis is used to replicate cells, for example, skin
cells that scraped or cut.
Meiosis is a process where a single cell divides twice to produce four cells containing half the
original amount of genetic information. Meiosis is found in sexual reproduction of organisms.
3. How many divisions are there in mitosis, in meiosis? What do 1N and 2N stand for?
(A) Mitosis is a single cell division - one diploid cell divides into two diploid cells.
Meiosis consists of one diploid cell undergoing two cell divisions yielding four haploid cells
usually called gametes.
1n = haploid, Sex cells are haploid. 2n = diploid. 2n or diploid can be used to describe cells
with all the genetic material which would be 46 chromosomes in humans.
4. List the sequence of all the stages in the cell cycle.
(A) The cell cycle is a four-stage process in which the cell increases in size (gap 1, or
G1, stage), copies its DNA (synthesis, or S, stage), prepares to divide (gap 2, or G2, stage),
and divides (mitosis, or M, stage).
5. What is crossing over and what does it result in?
(A) Crossing over occurs between prophase 1 and metaphase 1 and is the process where
homologous chromosomes pair up with each other and exchange different segments of their
genetic material to form recombinant chromosomes.
6. What is nondisjunction and what can happen to the gamete cells being formed?
(A) If nondisjunction occurs during anaphase I of meiosis I, this means that at least one pair
of homologous chromosomes did not separate. The end result is two cells that have an extra
copy of one chromosome and two cells that are missing that chromosome.
7. Define silent mutation, nonsense mutation, missense mutation, frameshift mutation and
point mutation.
Silent mutations are base substitutions that result in no change of the amino acid or amino
acid functionality when the altered messenger RNA (mRNA) is translated.
Nonsense mutation: a stop codon replaces an amino acid codon, leading to premature
termination of translation.
Missense mutation: a single nucleotide change results in a protein in which one amino acid is
substituted for another.
Frameshift mutation: causes a change in the reading frame, leading to unrelated amino acids
into the protein.
Point mutation: affects only one or very few nucleotides in a gene sequence.
8. Will a lethal gene mutation in a somatic cell be passed on to the next generation?
Explain your answer.
(A) A somatic cell mutation in an organism is passed on to daughter cells in the organism. But
this type of mutation doesn't affect future generations because only genes carried by
sperm or egg will affect offspring.
9. How does DNA replication lead to the transmission of genetic information?
(A) Segments of the DNA will be copied during protein synthesis and used to make proteins
to carry out cell functions or characteristics.
10. What is meant by “the DNA genetic code is universal”?
(A) The rules of base pairing explain the phenomenon that whatever the amount of adenine
(A) in the DNA of an organism, the amount of thymine (T) is the same (called
Chargaff's rule). Similarly, whatever the amount of guanine (G), the amount of cytosine (C) is
the same.
11. What is the base pairing rule? Which bases pair together?
(A) The rules of base pairing explain the phenomenon that whatever the amount of adenine
(A) in the DNA of an organism, the amount of thymine (T) is the same (called Chargaff's
rule). Similarly, whatever the amount of guanine (G), the amount of cytosine (C) is the same.
12. List the sequence of nucleic acids involved in protein production.
DNA --- mRNA--- tRNA--- amino acids---protein
(A) Deoxyribonucleic acid (DNA) and Ribonucleic acid (RNA)
DNA: long chain of polymers, made up of monomers; the building blocks called nucleotides,
made of: a sugar, deoxyribose; a phosphate molecule and a nitrogenous base: adenine (A),
Thyamine (T), Guanine (G), Cytosine (C).
RNA: act as a messenger carrying instructions from DNA for controlling the synthesis of
proteins, although in some viruses RNA rather than DNA carries the genetic information.
13. What do we call the section of DNA that is used to produce a protein?
(A) (instructions are found in) a gene
14. What is it about DNA in living things that gives genetic engineers the ability to take a
gene from one species and put it into another and have it work?
(A) Universal genetic code for all organisms, G C A T, order changes…
15. How does DNA determine the sequence of amino acids in a protein?
(A) The sequence of nucleotides, coded in triplets (codons) along the mRNA, thatdetermines
the sequence of amino acids in protein synthesis.
16. Make sure you are familiar with how to use an mRNA genetic code chart.
(A) Ex) DNA = C T C, mRNA = G A G, amino acid = glutamic acid
DNA = A G A, mRNA = U C U, amino acid = serine
17. Make sure you are familiar with a Monohybrid crosses, genotypic ratios and phenotypic
ratios. For example: Long ears are dominant over short years in rabbits. What are the
genotypic and phenotypic ratios in a cross between two heterozygous rabbits?
Complete the cross & ratios:
L
l
L
LL
Ll
l
Ll
ll
Phenotype: 3 long ear, 1 short ear
Genotype: 1 LL : 2 Ll : 1 ll
18. Make sure you can set up and interpret a dihybrid cross.
19. Make sure you can interpret a pedigree.

= ee , I1 = ? = Ee
20. Make sure you can interpret a karyotype.
(A) Ex) Monosomy, Trisomy
on somatic cells, XXY…on sex
cells.
XY = male, XX = female
21. Make sure you can interpret a DNA fingerprint.
(A) DNA is separated based on size, if DNA is exactly the same then a match to the
original DNA. Ex.) Matching a suspect’s DNA to the crime scene DNA.
22. What is a transgenic organism? Why can we put a gene from one organism into another
and have it work?
(A) (1) Transgenic organism; “genetic engineering”, genes of one species can be modified, or
genes can be transplanted from one species to another. (2) protein synthesis is common to all
organisms , DNA genetic code.
23. Make sure you understand genetic engineering and the use of bacteria and plasmids.
(A) Bacteria are used for replicating and altering genes that can be introduced into
plants or animals. Bacteria are used in genetic manipulation partly because of their rapid
reproduction rates and ease to produce a genetically identical population - a clone of
bacteria. The cells can then be lysed and DNA can be isolated. Bacteria are used to
produce non-bacterial proteins, for example for vaccine use. Such proteins can be safer
and as effective as vaccines that contain killed or attenuated (weakened) pathogens.
Genetic engineering can also produce extensive changes in the bacterium's metabolism.
For example, bacteria can be provided with several genes, encoding enzymes that allow
the production of fuel alcohol from wood.
Plasmid, a small ring of DNA, can carry accessory genes from bacterial chromosomes. A
plasmid can encode a protein that offers its host a selective advantage. For example, a
plasmid that encodes an antibiotic allows its host bacterium to thwart competing
microbes. Alternately, a bacterium might possess a plasmid that encodes antibiotic
resistance. Plasmids are readily isolated from bacterial cells and can be altered in vitro
by inserting or deleting specific sequences of DNA. Because they can be used to create
clones of genes, plasmids are called cloning vectors.
24. What is a restriction enzyme and what does it do?
(A) enzyme produced by certain bacteria that cuts DNA molecules at or near a specific
sequence of bases.
25. What is “artificial selection”?
(A) “Selective breeding”, intentional reproduction of individuals in a population that have
desirable traits. Ex) dog breeding like golden doodles (golden retriever and a poodle) for
poodle hair and retriever traits.
26. What is PCR and what is it used for?
(A) PCR (polymerase chain reaction) is a technique in molecular genetics that permits the
analysis of any short sequence of DNA (or RNA) even in samples containing only minute
quantities of DNA or RNA. PCR is used to analyze forensic evidence.
27. What is cloning and how do the organisms produced compare genetically?
(A) Cloning describes a number of different processes that can be used to produce
genetically identical copies of a biological entity, the copied material, which has the same
genetic makeup as the original.
28. What are some of the concerns with genetic engineering and the production of
genetically modified organisms?
(A) Benefits; add vitamins to foods for poor countries (ex. “The Golden Rice Project”
biosynthesize beta-carotene, a source of Vit. A to rice to benefit children in Arica),
producing vaccines, pesticide resistant crops. Risks; traits transferred to unwanted
organisms (ex. plants), allergic responses, “super weeds” that are resistant to herbicide
glyphosate and overuse of Monsanto’s “Roundup Ready trait.
http://www.ucsusa.org/food_and_agriculture/our-failing-food-system/genetic-engineering/risks-of-geneticengineering.html#.WS9Qhevyu00
29. What is gel electrophoresis? Why & how do the segments of DNA separate?
(A) Gel electrophoresis is a laboratory method used to separate mixtures of DNA, RNA, or
proteins according to molecular size.
30. What is natural selection and how can a genetic variation become an adaptation that
leads to evolution?
(A) Natural selection is the process whereby organisms better adapted to their environment
tend to survive and produce more offspring. A genetic variation can benefit an organism to
survive in harsh environments, for example Darwin’s bigger versus smaller beaks.
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31. What is “biological fitness”?
(A) …the ability to survive to reproductive age, find a mate, and produce offspring.
32. What are the four principles of Darwin’s theory of natural selection?
(A)
•
•
Variation - Within any population, individuals differ from one another in many ways.
Heritability - Some differences between individuals are inheritable, and can be passed
from parent to offspring.
•
•
Overproduction - In most populations, more young are born than can survive. Many of the
young will die. A few will live long enough to reproduce.
Reproductive Advantage - an individual’s survival depends mainly on the individual’s
traits. Those that are better suited to their environment may pass their traits to the next
generation.
33. How can we use the DNA similarities in related organisms to explain, “descent from a
common ancestor”?
(A) In evolutionary biology, a group of organisms share common descent if they have
a common ancestor.
34. Define homologous structure and analogous structure and give an example of each.
(A) Homologous structure - the structures in different species with a common ancestor
Analogous structure - the various structures in different species having the same
function but have evolved separately, thus do not share common ancestor.
35. What is the difference between biotic and abiotic factors?
(A) Biotic - living factors (derived from living organisms) (ex. animals, plants,
microorganisms, dead organisms, animal wasted)
Abiotic – nonliving factors (ex. rocks, weather, sunlight, water)
36. What is the role of decomposers in the environment?
(A) Organic matter is recycled in an ecosystem by decomposers. Decomposers are organisms
such as bacteria and fungi that break down the organic matter in the dead bodies of plants
and animals and recycle the nutrients.
37. With continued global warming, ocean levels are rising. Where is this extra water coming
from?
(A) Ice is melting, shrinking glaciers (Muir Glacier, Alaska)
https://climate.nasa.gov/climate_resources/4/ and ice sheets (Greenland)
https://www.nasa.gov/feature/goddard/warming-seas-and-melting-ice-sheets are adding to
ocean’s waters.
38. How can a food web or a food chain be used to show energy flow in the environment?
(A) In ecology, a food chain is a series of organisms that eat one another so that energy and
nutrients flow from one to the next.
The degree of reduction between trophic levels varies in different ecosystems, but the rule
of thumb is that only about 10 percent of the energy at one level is present in the next. This
is because the organisms at each level are using most of this energy for their own needs.
39. What is the difference between an autotroph and a heterotroph?
(A) Autotrophs make their "food" through photosynthesis using the energy of the sun.
Chemosynthesis is used to produce food using the chemical energy stored in inorganic
molecules (Deep in ocean at hydrothermal vents, vent bacteria oxidize hydrogen sulfide).
Heterotrophs cannot make their own food, so they must eat or absorb it.
40. What is a producer, a consumer, a carnivore and an herbivore?
(A) Producer (autotroph), like green plants, an organism that makes its own food, at the
bottom of the food chain/web.
Consumers (heterotrophs), like rabbits, are organisms that obtain nutrients from other
organisms.
Herbivores are animals that feed only on plants. Rabbits, cattle, horses, sheep and deer are
all herbivores.
Carnivores are animals that feed on other animals. Some carnivores may be predators (such
as lions, hawks, and wolves who attack and kill their prey and feed on their bodies) and some
may be scavengers (they feed on dead animals that they find, like vultures).
Omnivores are animals that feed on both plants and animals. Examples of omnivores are
humans and bears.
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41. Can two species live in the same environment if they use the same resource for food?
Explain your answer.
(A) Two species compete for food in the same environment, if their niches (roles in the
environment) overlap. Each organism will reproduce dependent upon the carrying capacity
(resources available) in the environment.
42. What is carrying capacity?
(A) the maximum population size of the species that the environment can sustain
indefinitely, given the food, habitat, water, and other necessities available in the
environment.
43. Explain how elements and compounds in the environment are recycled but energy is not.
(A) Elements, chemical compounds, and other forms of matter are passed from one organism
to another and from one part of the biosphere to another through biogeochemical cycles.
Matter can cycle because biological systems do not use up matter, they transform it.
The largest source of energy for an ecosystem is the sun. Energy that is not used in an
ecosystem is eventually lost as heat. Energy and nutrients are passed around through the
food chain, when one organism eats another organism. Any energy remaining in a dead
organism is consumed by decomposers. Each organism must use some energy that they
received from other organisms in order to survive. The top consumer of a food chain will be
the organism that receives the least amount of energy.
44. What would happen to the atmospheric carbon dioxide level with more plants on the
earth, less plants on the earth, and why?
(A) Land plants and the ocean have taken up about 55 percent of the extra carbon people
have put into the atmosphere while about 45 percent has stayed in the atmosphere.
Eventually, the land and oceans will take up most of the extra carbon dioxide, but as much as
20 percent may remain in the atmosphere for many thousands of years.
Excess carbon in the atmosphere warms the planet and helps plants on land grow more.
Excess carbon in the ocean makes the water more acidic, putting marine life in danger.
https://earthobservatory.nasa.gov/Features/CarbonCycle/page5.php
In the Amazon alone, scientists estimate that the trees contain more carbon than 10 years
worth of human-produced greenhouse gases. When people clear the forests, usually with
fire, carbon stored in the wood returns to the atmosphere, enhancing the greenhouse effect
and global warming. Once the forest is cleared for crop or grazing land, the soils can become
a large source of carbon emissions, depending on how farmers and ranchers manage the
land. https://earthobservatory.nasa.gov/Features/Deforestation/deforestation_update2.ph
p
Plants also need water, sunlight, and nutrients, especially nitrogen. If a plant doesn’t have
one of these things, it won’t grow regardless of how abundant the other necessities are.
There is a limit to how much carbon plants can take out of the atmosphere.
Tropical forests may also be extremely susceptible to drying. With less water, tropical trees
slow their growth and take up less carbon, or die and release their stored carbon to the
atmosphere.
45. Define mutualism, parasitism, competition and commensalism?
(A) Symbiotic relationships: interaction between two different organisms living in close
physical association
Mutualism: relationship between two organisms in which both benefit
Parasitism: relationship between two organisms in which one benefits and the other (host) is
harmed
Competition: limited supply of at least one resource (such as food, water, and territory)
within and between species
Commensalism: relationships between two organisms where one organism benefits from the
other without affecting it.
46. Explain a “predator/prey” relationship?
(A) A predator is an organism that eats another organism. The prey is the organism which
the predator eats. Some examples of predator and prey are lion and zebra, bear and fish,
and fox and rabbit.
47. Review the characteristics of the major Biomes.
48. Can you list the classification taxons in order? Something about King Philip……..
(A) kingdom, phylum or division, class, order, family, genus, species

“ King Phillip Came Over From Great Spain “
49. Make sure you are familiar with how to use a dichotomous key.
50. Review the major features of the 6 kingdoms from your notes.