Gen-Genetic, WSU MBIOS 301

It's happening again but now I miss the past torture

What is chromosomal theory of inheritance and what are its fundamental principles?

The explanation of how the pattern of traits transmitted to offspring come about during meiosis and fertilization. Principles: Chromosomes contain genetic information transmitted from parent to child; chromosomes are replicated and passed from generation to generation and cell to cell during the development of a multicellular organism; nuclei of most eukaryotic cells contain chromosomes found in homologous pairs (diploid cells) with one half of the pair coming from one parent and the other coming from the other; during meiosis chromosomes segregate independently of each other; at fertilization each parent contributes one set of chromosomes.

Mendals Law of segregation v Law of independent assortment

Since gametes can only have one allele/type of chromosome the alleles segregate away from each other during meiosis v the randomness of with different genes get partnered up together during metaphase 1 & 2. Don’t v do affect the inheritance pattern of two or more types of genes.

How to calculate probability

For calculating unrelated events happening simultaneously, multiply their individual chances together (product rule).

Hypothesis testing

Use of statistical tests to determine whether data from genetic crosses are consistent with a specific pattern of inheritance.

Incomplete dominance v codominance

Showing a secret third option v showing both at same time.

Null hypothesis

Accepted if there is no real (p value is smaller than decided value) dif between the expected and the observed.

How to find p value from Chi square test - Ignore the ^2 on the X

Add the values from this equation gotten from each trait observed and add them together for the final chi square value

Degree of freedom

Measurement of the number of independent categories (minus 1 from total).

Order of generation

P, F1, F2, etc.

Thomas Hunt Morgan

Scientist that played with flies and used white eyes in makes to prove the certain genes are on certain chromosomes by using the x chromosome (accidently also giving way for sex-linked genes)

Test cross v reciprocal cross

Dominant phenotype but unknown genotype is crossed with a recessive phenotype. V the sexes and phenotypes are reversed and compared to previous cross.

Pleiotropy/pleiotropic

One gene affects many traits.

Nettie Stevens

Used meal worms to figure out sex chromosomes by choosing whether an egg would be fert with y or x chromosome.

Dosage compensation

Makes sure that although females have two x chromosomes, they don’t have extra genes being expressed.

Barr bodies

Condensed x chromosomes to make those genes unexpressed

Bipotential gland

Can be testis or ovary depending on presence of SRY gene that triggers hormone changes.

Crossing over/chiasma formation

The exchange of DNA between nonsister chromatids of homologous chromosomes. Site where it occurs is called the chiasma. Results in genetic recombination.

Synapsis

Homologous chromosomes align themselves together along their length,

Recombinant offspring

Shows a mix of phenotypes, not exactly matching either parent.

Synteny/syntenic genes

Two or more genes on the same chromosome from being physically linked together or bc of circular chromosomes.

Genetic/chromosome/gene mapping and how it’s measured

Using the amount of recombination from test crosses to estimate the physical distances and order of genes on the same chromosome. Measured in map units/centimorgans that are equal to 1%.

Psuedoautosomal Region (PARs)

Where y and X chromosomes can pair up for crossing over. The genes on these sections are not sex-linked and instead follow a autosomal inheritance pattern.

Plasmid

A DNA molecule that can exist independently of a bacterial chromosome.

Transformation v transduction v conjugation

Bacteria cell taking up DNA from environment v from another bacteria cell because of a virus making a mistake (moving genome from one cell instead of its own) v from another bacteria cell directly (sex pilus)

Competence factor and competent cell

The protein complex on a cells membrane that allows it to take up foreign DNA from its environment.

Homologous v non homologous recombination

Putting in DNA into a bacterial chromosome as one half of an already present gene v adding in both strands of DNA at a random spot.

F/F+/Fertility plasmid

A small circular segment of DNA that can allow the cell it inhibits (F+ cell) to be the donator in conjugation.

F- cell

A cell that does not have an F factor like an Hfr cell.

Hfr cell and its strain

The cell that takes in the F factor from a F+ plasmid. The bacterial chromosome that received an F factor is the HFr strain

F’/F prime factor

An F factor that carries bacterial chromosome after being excised. The cell it inhibits is an F+ cell.

What a virus genome is made of

DNA or RNA

Integrase

An enzyme that some viruses have that can cut host chromosomal DNA and integrate the viral genome.

Lysogenic cycle v lytic

Sit and wait to spread more v explode.

Lysogenic cycle

Viral DNA get incorporated into the cell’s chromosomes and does not make new phages. Lytic cycle is activated by abundance of nutrients.

Lytic cycle

Infected cell synthesizes new phages and bursts releasing them.

When and how viral genes are expressed

Expressed immediately by host cell enzymes and ribosomes.

Bacteriophage

A virus that infects bacteria

Virus

An infectious particle of nucleic acid molecules enclosed in a protein coat.

Retrovirus

RNA genome that synthesizes DNA through RNA transcription/reverse.

Why DNA has a negative charge

Due to negative charge on each phosphate group in sugar-phosphate backbone.

Phosphodiester/phosphoester linkage

Connects two adjacent sugar molecules together via a phosphate group

Purine v pyrimidine

A or G base (double rings and wider) v T, C, or U base (single rings and narrower). Pairs: AT & GC (DNA) v AU & GC (RNA). AT and AU make double bonds while GC makes triple bonds

How the information of DNA and RNA is stored

In the order of nucleotides

Type of hydrogen bond between A and T v C and G

Double v Triple.

What the directionality of a DNA strand is determined by

The numbering system of the sugar.

Major v minor grooves

The wider (and can hydrogen bond with proteins) v narrower groove in DNA helix

Scientists: Avery, MacLead, and McCarty

Firgured out that it was DNA that passes on info from degrading DNA, RNA, and protein and figuring out that degrading dangerous DNA in bacteria would let the mice live.

What makes up nucleotides

Phosphate group (reason why DNA & RNA are (-)); a pentose sugar (deoxyribose in DNA and ribose with an extra OH on C2 in RNA); and nucleic bases (ATGC in DNA and AUGC in RNA).

Erwin Chargaff’s Rule

A=#T or #U and #G=#C

Rosalind Franklin

Took the photo that helped figure out the shape of DNA