Final Exam SG Semester 2
Biology H 2015
Biotechnology
PCR-process that makes many copies of a segment of DNA, also called gene cloning
restriction enzymes-cut DNA at specific nucleotide sequences, produces “sticky ends”
point mutation- Change in a single nucleotide, can change only 1 amino acid
Frame shift mutation-changes the codons being read from the point of the mutation through the rest
of the protein
gene therapy-inserting a good copy of a gene into a cell in order to treat a genetic disorder
recombinant DNA-DNA of two different species combined together, can be combined into a plasmid
and inserted using a vector
ligase-enzyme that fuses pieces of DNA together
plasmid DNA-circular piece of DNA, separate from the main chromosome of a bacteria, can give
bacteria genes that help them survive
cloning-reproduction and growth of genetically identical offspring
gel electrophoresis-process that separates pieces of DNA based on size
reverse transcriptase-enzyme that makes a DNA copy from an RNA molecule
Why do we identify genes on chromosomes? To learn about the gene and disease caused by mutations
in them
How big is the human genome? 3 billion base pairs
What does “gene mapping” mean? Determines the location of a gene on a chromosome
Why did scientists sequence the genome of E. coli? Because it's small, it causes disease, it is found in
our intestines
Why can cystic fibrosis be treated with gene therapy? It's a disease caused by a single gene
Why can recombinant bacteria grow in antibiotic media? Because they have been given the gene for
antibiotic resistance
What are the steps in splicing and inserting a plasmid into bacteria? Extract plasmid from a bacteria,
cut plasmid, bond plasmid to gene, seal with ligase, transform bacteria
Be able to interpret a gel
What are the uses of biotechnology? Clean up toxic waste, manufacture therapeutic proteins
Genetics and Protein Synthesis
How does DNA control protein synthesis? The nucleotide sequence of DNA controls the sequence of
amino acids in a protein
What are proteins made of? Amino acids
What is the sequence of events in transcription? Attachment of RNA polymerase to DNA, initiation,
elongation of RNA, termination
What is the effect of a mutation on a protein? Can change the amino acid sequence in a protein, can
change its function
Describe each type of mutation; What is the result of each type?
point, frameshift, See biotechnology section
nonsense-creation of a stop codon in a protein, no more amino acids will be added
non-disjunction-failure of chromosomes to separate during meiosis
What happens in RNA processing? Addition of the cap, tail, and splicing out of introns
What is the role of tRNA in protein synthesis? Bring amino acids to ribosomes
What is the role of mRNA in protein synthesis? Carries the code to build a protein to the ribosome
Where are proteins synthesized? At the ribosome
Which type of mutation causes sickle cell disease? Point mutation
What is the worst type of mutation on a proteins function? Frame shift (insertion or deletion) at the
beginning of a protein
Genotype: type of alleles an organism has, determines the phenotype
Probability rules of getting heads: 1/2, tails: 1/2, a boy: 1/2, two boys: 1/4
Dominant vs. recessive alleles/traits: dominant can hide a recessive trait, if you get 1 dominant allele
you show the dominant trait
Principle of segregation: homologous chromosomes and alleles separate during meiosis so each gamete
ends up with one of each
Types of gametes produced by: AABb, AaBb: AB, Ab, AB, Ab, aB, ab
Monohybrid and dihybrid ideal ratios: Aa x Aa, AA x aa, AaBb x AaBb
Sex-linkage, determination, inheritance—trait is a sex chromosome (most are on the X chromosome),
Mom gives and X to all of her daughters and sons, dad gives an X to his daughters and a Y to his sons
and determines the sex of the offspring
Human blood type problems A x B, A x A, AB x O
Polygenic inheritance and examples: trait controlled by more than 1 gene, eye color, skin color, usually
a bell curve distribution in a population
Be able to interpret a pedigree chart-- squares are males, circles are females, if they are colored in
they have the trait
Why are calico cats always female? They need to have 2X chromosomes to be heterozygous for color,
1 X is inactivated at random giving them patches of color
Animal development and Internal Responses
zygote-fertilized egg, formed by fusion of egg and sperm
cleavage-early cell division without growth
differentiation- cell starts to produce proteins that make it develop into a certain cell type
blastula-hollow ball of cells produced by cleavage
induction-chemical released by one cell type causes a change in another cell type
notochord—becomes the backbones
yolk—energy rich food for the embryo
morphogenesis- formation of body structures
determination-genes get turned off, beginning of becoming different
metamorphosis-change in body form between juvenile and adults
activation-causes the fertilized egg to begin dividing
fertilization-fusion of egg and sperm
depolarization-switching of charges in a neuron to carry an impulse
Repolarization-restoration of resting potential in a neuron, has to happen before a neuron can carry
another impulse
antigens-proteins on the outside of cells that allow them to be identified
antibodies-produced by B cells in response to antigens
memory cells-remembers how to fight a specific invader, gives you immunity to a pathogen
T cells-help B cells make antibodies
B cells-make antibodies
cytotoxic cells-kill your infected body cells to prevent pathogens from reproducing
homeostasis-maintenance of internal body conditions
placenta- brings nutrients to and waste products away from a fetus
umbilical cord-connection between a fetus and the placenta
# of chromosome in a gamete 1/2 as many as in a body cell
Sequence of events in animal development: fertilization, growth, differentiation, morphogenesis
What is the result of cleavage? the blastula
What is the fate of each germ layer? Ectoderm-skin and nervous system, mesoderm-muscles and
bones, endoderm-digestive system
How do identical twins form? When an embryo splits into two babies
What is the gene-equivalence hypothesis? All cells have the same genes
What happens to genes during differentiation? Their ability to express protein becomes restricted
How is a nerve impulse transmitted? Chemical and electrical changes across the cell membrane
How are impulses transmitted between neurons? Across a synapse by neurotransmitters
What is the direction an impulse travels in a neuron? from dendrite to axon
What is “self vs. non-self” in our immune system? The ability of our immune systems to recognize our
cells vs pathogen cells
Give several examples of non-specific immunity. Skin, mucous membranes, macrophages, phytoalexins
in plants, fever, antibacterial enzymes
What is the cause of inflammation? Histamine
Which type of immunity works against the most types of invaders? Non-specific immunity
How do vaccines promote immunity? They allow your body to make antibodies against antigens without
making you sick
What are the effects of histamine? It makes capillaries swell up and get leaky, cause allergies
Describe and give examples of both negative feedback and positive feedback systems. Negative
feedback-brings you back toward normal, insulin and glucagon work together to maintain blood sugar
levels , positive feedback brings you farther away from normal, child birth, blood clotting
What is a target cell? The cell a signal can act on
Why can cells respond differently to a hormone? Because they have different signal transduction
pathways inside them
What are the effects of insulin? Lower blood sugar levels Of glucagon? Raises blood sugar levels
Evolution
microevolution- change of allele frequency in a gene pool, can happen quickly
macroevolution -can lead to speciation, takes a long time
gene pool-all the alleles in a population
variation-differences between members of a species
species-group of organisms that can interbreed and produce fertile offspring
homologies-structures that indicate common ancestry
adaptive radiation-burst of microevolutionary activity that can lead to the formation of many species
from a common ancestor in a relatively short period of time
Be able to solve Hardy-Weinberg problems, know the assumptions: population is diploid and sexually
reproducing, non-overlapping generations, random mating and union of gametes, large population, no
mutation or migration; p + q =1, p2 + 2pq + q2 = 1
What is the unit of evolution? Population
What is the relationship between Natural Selection and gene pools? It increases the frequency of
alleles that increase fitness and decrease the frequency of those that decrease fitness
What factors change gene pools? Natural selection, genetic drift, gene flow, mutation
What are the characteristics of hybrid offspring? They are sterile
What do homologies indicate? Common ancestry
List the order of taxa from largest to smallest domain, kingdom, phylum, class, order, family, genus
species
Why do we use scientific names? Because common names can be different in different places
Know the characteristics of each Kingdom: Monera: unicellular, auto and heterotrophic, prokaryotes,
motile; Protista: uni and multicellular, auto and heterotrophic, motile and non-motile; Fungi: uni and
multicellular, heterotrophic, non-motile; Plantae: autotrophic, multicellular, non-motile; Animalia:
heterotrophic, multicellular, motile
Why can classification of an organism change? Because additional information is learned
Types of isolating mechanisms: geographic-live in the same habitat but don't meet so they can't mate;
seasonal-timing of reproduction; mechanical-parts have to fit together to deliver the gametes;
behavioral-mating rituals, if you don't know the dance you can't mate
Ecology
primary consumers- eat producers
producers-convert light energy into chemical energy, base of every food chain
secondary consumers-eat primary consumers
decomposers-recycle the atoms
food web-show the energy and feeding relationships between organisms
food chain-one organism at each trophic level
competitive exclusion: different species use different resources in a habitat to lesson competition
niche: role of an organism, all the biotic and abiotic resources an organism needs
parasitism- +/- relationship
symbiosis-any relationship between organisms
commensalism- +/0 relationship
mutualism- +/+ relationship
exponential growth- growth without limiting factors
chaparral: our ecosystem, needs periodic fires
photic zone: region of the ocean that gets light, photoautotrophs live here
Aphotic zone: deep water, chemoautotrophs are the producers here
abyssal zone: bottom floor of the ocean
Which trophic level is most affected by toxins? the top level consumers
Which elements get recycled? All of them
What happens when you add carbon dioxide to water? the pH levels go down
Why is the amount of carbon dioxide increasing in the atmosphere? Burning fossil fuels
How have ecosystems been disturbed? Human consumption, use of chemicals, introduction of nonnative species
What is the main dispersal agent? Humans
What is the first life on bare rock? Mosses and lichens
Primary vs secondary succession; what is the result? Primary is from bare rock, secondary is after a
disturbance, result is climax community
What are the characteristics of the best colonizer plants? Very tolerant of temperature and moisture
levels
What is the greenhouse effect? Greenhouse gasses trap the UV light causing an increase in
temperature near the earths surface
How do plants effect an ecosystem? They affect temperature and moisture levels by absorbing
sunlight and releasing moisture through transpiration