Ohio Biology EOC Review

What are genes?

Genes are sections of DNA that control a single genetic trait and code for a protein.

What is the central dogma of molecular biology?

DNA -> RNA -> Protein

What process makes mRNA?

transcription

What process makes proteins?

translation

Name the base pairs in DNA

A-T
G-C

Name the base pairs in RNA

A + U, C + G

What determines the shape of a protein?

sequence of amino acids

What is genetic recombination?

the production of offspring with combinations of traits differing from either parent

What are two types of genetic recombination?

crossing over and independent assortment

Crossing over is

Process in which homologous chromosomes exchange portions of their chromatids during meiosis.

Independent assortment

Independent segregation of genes during the formation of gametes

How can a mutation affect a protein?

It can have NO EFFECT on a protein or change the structure and function of the protein.

When is a DNA mutation harmful?

If the protein the DNA codes for can not function properly.

Is DNA identical in all cells of an organism?

Yes!

Complete dominance

a relationship in which one allele is completely dominant over another

Incomplete dominance

Situation in which one allele is not completely dominant over another allele, causing a mix of traits.

Codominance

A condition in which neither of two alleles of a gene is dominant or recessive, and both traits are expressed.

Sex-linked traits

Traits controlled by genes located on sex chromosomes.

Where does translation occur?

ribosome

Where does transcription occur?

nucleus

genetic engineering

Process of making changes in the DNA code of living organisms

What is the goal of genetic engineering?

to produce organisms with new & improved characteristics and correct a malfunction

What are restriction enzymes?

They cut the DNA into specific parts

What is cloning used for?

Cloning can be used to make a copy of a particularly good strain of plant

What is gene therapy?

the transplantation of normal genes into cells in place of missing or defective ones in order to correct genetic disorders.

What is gel electrophoresis?

the separation of charges molecules using an electric field

What are three types of genetic engineering?

Cloning, gene therapy, gel electrophoresis

How do the order of bases affect the protein made?

the order of bases in a section of DNA decides the order of amino acids in the protein. these amino acids then fold to produce specifically shaped proteins such as enzymes

Why must DNA be able to make copies of itself?

For the organism to grow and use DNA in different cells for unique functions.

Compare and contrast the genetic makeup of two different cells in the SAME organism.

The DNA will be identical in both cells, but different genes in each cell are used.

Why is selective breeding used?

Scientists are able to use organisms with beneficial traits and mutations for reproduction, and the positive mutations are spread out and variation occurs.

How many phenotypes are involved in incomplete dominance?

THREE

Why does a gene mutation change a protein?

The sequence of amino acids changes, and therefore the protein changes. The protein that helps make the specific trait can't do its job.

What is genetic drift?

A change in allele frequencies caused by random events

If the allele frequency is not constant, what is occurring?

Evolution

What factors can disturb the genetic equilibrium and cause evolution to occur? (5)

Sexual selection, small population size, immigration or emigration, mutation, and natural selection.

What is sexual selection?

Mate preference by one sex for certain characteristics in individuals of the other sex.

How does sexual selection lead to evolution?

The allele frequencies change due to a preference for or against an allele, so genetic equilibrium is thrown off.

In what types of populations do genetic drift occur?

Small populations, because a certain allele can become more common and represented.

Immigration

Moving into a population

Emigration

Migration from a location

How do mutations cause genetic variation?

Mutations cause new alleles to appear in a gene pool, due to a changed protein, and this leads to a change in allele frequencies and evolution.

What is speciation?

the formation of new and distinct species in the course of evolution.

Two types of gene flow

immigration and emigration

What is used as evidence for evolution?

homologous structures and selective breeding of domesticated animals, similar DNA base sequences.

What is reproductive isolation?

when the members of two populations cannot interbreed and produce fertile offspring

What are three types of reproductive isolation?

behavioral, geographic, temporal

behavioral isolation

isolation between populations due to differences in courtship or mating behavior

Geographic isolation

form of reproductive isolation in which two populations are separated physically by geographic barriers such as rivers, mountains, or stretches of water

How much energy is passed from one trophic level to the next?

10%

Why is only 10% of energy transferred between trophic levels in an energy pyramid?

Most of the energy is used directly by the organism for breathing, finding food, and mating and is released as heat.

How are molecules recycled?

Biogeochemical cycles help pass atoms that are used for different functions. Matter is only transformed, not created or destroyed.

What do similar organisms share?

Similar DNA sequences and similar homologous structures(morphology)

What is carrying capacity?

the number of people, other living organisms, or crops that a region can support without environmental degradation.

What is exponential population growth?

The expansion of a population in an ideal and unlimited environment

What is logistic population growth?

occurs when the growth rate decreases as the population size approaches carrying capacity

Ecosystem Homeostasis

The ability of an ecosystem to maintain steady equilibrium by responding to internal and external negative feedback systems

What caused ecosystems to be change?

Competition, predation, disease, weather.

What are invasive species?

Non-natives that overrun native species in ecosystems

What are niches?

All ways an organism interacts with the environment (jobs)

What is photosynthesis?

the process by which green plants and some other organisms use sunlight to synthesize foods and oxygen from carbon dioxide and water.

What is cellular respiration?

Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen and creates ATP.

What can change an enzyme?

Substrate Concentration, pH, temperature and physical force.

What is a hypertonic solution?

Solute concentration is greater than that inside the cell; cell loses water

What is a hypotonic solution?

the solution has a lower solute concentration than the cell so water moves into the cell causing plant cells to swell and animal cells to swell and burst

What is an isotonic solution?

Contains equal concentratinos of solutes on both sides.

reactants of photosynthesis

carbon dioxide and water

reactants of cellular respiration

glucose and oxygen

Chemosynthesis

process by which ATP is synthesized by using chemicals as an energy source instead of light

Passive transport

Requires NO energy, Movement of molecules from high to low concentration, Moves with the concentration gradient

Active transport

Energy-requiring process that moves material across a cell membrane against a concentration difference

What is the role of carbohydrate?

Supply energy to the body

What is the role of lipids?

long term energy storage, insulation, cell membrane

What is the role of nucleic acids?

Source of genes & hereditary information