BIOLOGY 1010 final exam prep Utah State University (USU)

Dominant

An allele that is always expressed

recessive

An allele that is masked when a dominant allele is present

allele

Different forms of a gene

Homozygous

An organism that has two identical alleles for a trait

Heterozygous

An organism that has two different alleles for a trait

Genotype

genetic makeup of an organism

phenotype

physical characteristics of an organism

carrier

also used to descrive heterozygous individuals

autosomal trait

gene located on an autosome, which are human chromosomes numbered 1-22

sex-linked trait

gene located on the X sex chromosome

codominance

both alleles expressed in the heterozygote

incomplete dominance

an intermediate phenotype in heterozygotes

polygenic traits

determined by multiple genes and typically have a continuum of phenotypes i.e. human skin or eye color

sex-linked traits are...

indicated by males being affected disproportionately

dominant traits are...

typically present in every generation

recessive traits are...

seen in children with unaffected parents

DNA >> RNA

transcription, RNA polymerase

RNA >> Protein

translation

transcription before...

translation

DNA consists of a four-letter language:

A, T, C, and G

RNA consists of a four-letter language:

A, U, C, and G

Proteins are built from ___ different amino acid building blocks

20

proteins made determine...

phenotype

transcription takes place in

the nucleus

The main enzyme in transcription is

RNA polymerase

In transcription gene(s) are transcribed into complementary

mRNA

the gene (DNA) "unzips"

step 1 of transcription

a single strand of DNA is used as a template to build complementary mRNA

step 2 of transcription

the DNA "rezips"

step 3 of transcription

the mRNA transcript leaves the nucleus

step 4 of transcription

a complementary mRNA code to this DNA ATTCCGTATGG would be:

UAAGGCAUACC

translation occurs in...

ribosomes and rough ER

Three letters of mRNA is called a

codon

Each codon codes for

a specific amino acid

tRNA is another type of

RNA

tRNA brings ___ to a ribosome

amino acids

tRNA has a special three-base sequence that is called an

anticodon

Codons and anticodons must be complementary to each other in order for

an amino acid to be delivered to the ribosome

ribosomes assemble and the mRNA message is "read" three letters (a codon) at a time

Step 1 of translation

tRNAs with complementary anticodons bring their amino acids to the ribosomes

Step 2 of translation

the amino acid chain (a polypeptide/protein) is being made as amino acids are added until the mRNA code specifies a STOP codon

Step 3 of translation

The chain of amino acids created from translation is the

basic structure of the protein.

proteins determine

phenotype

Proteins then fold into _____ to do their jobs

complex shapes

Mutation

Random errors of DNA replication

In a mutation DNA could be...

substituted, inserted, or deleted

If errors are not detected/repaired then it's a mutation that can be

passed to the cell's descendants

When "mutated" DNA is then transcribed/translated it can

affect the protein that's made

Frameshift mutations are likely to affect the protein in a

big way

Mutations can be...

silent, harmful, or beneficial

Vaccines expose the individual to the...

antigen

antigen

some version or part of the bacteria or virus

vaccines...

initiate an immune response and production of antibodies to prevent future illness

New mRNA vaccines administer...

synthetic viral mRNA to the patient

synthetic viral mRNA produces an

immune response

Every cell has every gene which is...

the cells' genetic potential

combinations of genes are expressed (turned on) to allow cells to

differentiate and specialize

cells that have not differentiated and still have that genetic potential are

stem cells

Epigenetics

chemical tags attached to DNA sequences that are acquired over a lifetime and influence gene expression

Reproductive cloning is also abreviated as

(SCNT) somatic cell nuclear transfer

Reproductive cloning (SCNT)

uses an adult cell as the DNA donor, "deprograms" that adult cell and fuses it with an enucleated egg, transfers the early embryo to a surrogate, and allows the clone to gestate and be born

The clone is genetically identical only to...

the donor of the adult cell

clone a gene (molecular cloning) STEP 1

isolate the target gene

clone a gene (molecular cloning) STEP 2

insert the target gene into a bacterial plasmid

clone a gene (molecular cloning) STEP 3

get the plasmid back into the bacteria

clone a gene (molecular cloning) STEP 4

grow the bacteria

clone a gene (molecular cloning) STEP 5

collect the protein produced using the target DNA instructions

clone a gene (molecular cloning) includes the production of

insulin

Gel electrophoresis separates ____ fragments based on _____

DNA, size

DNA has a ____ charge

negative charge

smaller DNA fragments travel _____ through a gel

further

CRISPR is a tool for targeting, splicing, and editing

DNA

CRISPR utilizes a specifically designed guide ______ and a bacterial _____-cutting enzyme system

mRNA, DNA

a change in the allele frequency (or genetic makeup) of a population over time

evolution

Populations are the units of

evolution

natural selection

process through which living organisms adapt and change

Requirements in a population: (the recipe for natural selection, 3 things)

variation, heritability, reproductive advantages

sexual selection

selection of a trait that increases an individual's chance of mating even if that trait decreases the individual's chance of survival is called...

evolutionary fitness

how well a species is able to survive and reproduce in its environment; survival of the “fit enough” is called...

sources of genetic variation include:

Independent assortment during meiosis, crossing over, random fertilization, random mutations, new genetic combinations due to sexual reproduction

Divergent evolution

evolution in different directions from a common point; homologous structures indicate relatedness

examples of Divergent evolution

vertebrate forelimbs, reproductive structures in flowers

Convergent evolution

similar structures arise due to similar selective pressures; analogous structures do not indicate the trait originated in a common ancestor

examples of Convergent evolution

shark and dolphin body form or bird and bat wings

Mutation

a random error in gene replication that leads to a change

Natural selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates

Genetic drift

A change in the allele frequency of a population as a result of chance events rather than natural selection.

bottleneck effect

A change in allele frequency following a dramatic reduction in the size of a population

founder effect

change in allele frequencies as a result of the migration of a small subgroup of a population

Gene flow (migration)

movement of alleles from one population to another

biological species concept

defines a species as individuals capable of mating and producing fertile offspring

genetic divergence

the accumulation of genetic differences between two populations; requires reproductive isolation - could be prezygotic or postzygotic

speciation

formation of a new species

allopatric speciation

The formation of new species in populations that are geographically isolated from one another.

sympatric speciation

The formation of new species in populations that live in the same geographic area

prokaryotic

No nucleus

eukaryotic

Has a nucleus

Domain Archaea

single-celled prokaryotes; includes many extremophiles

Domain Bacteria

single-celled prokaryotes; bacteria

Domain Eukarya

eukaryotic organisms; protists, fungi, plants (multicellular), animals (multicellular