Explain ploidy

The number of sets of chromosomes in a cell

What is the ploidy for a haploid, diploid and hexaploid organism (___N)

1N, 2N, 6N

What are homologous chromosomes?

Chromosomes with the same gene at the same specific location

Define alleles

Different versions of the same gene

What is the max number of alleles per gene that a diploid organism can have?

2

What is the max number of alleles per gene that a hexaploid organism can have?

6

Define zygosity

A term used to denote similarity or dissimilarity of alleles in an organism

If an organism has AA or aa alleles it is said to be ____________________, whereas if it has Aa it is said to be _____________________.

Homozygous, heterozygous

What are the two places genes are found in eukaryote cells?

the nucleus and in the organelles

What are autosomes?

All nucleic chromosomes that are not sex chromosomes

What is autosomal variation?

Phenotypic variation linked to autosomal chromosomes

What is sex-linked inheritance?

Phenotypic variation linked to sex-determining chromosomes

What is cytoplasmic inheritance?

Phenotypic variation linked to organellar chromosomes

What is a pure-bred line?

A lineage with no variation in phenotype over generations (all homozygous)

What is a cross?

The introduction of new genes/traits from one variety or line into a new genetic background

What does it mean for an organism to "self"?

They create new offspring using only their own zygotes

ex. pollen and egg from the same flower

What is reciprocal pollination?

When plant A pollinates plant B's flower and plant B pollinates plant A's flower

What symbol is used to represent a parental generation?

P

What symbol would be used to represent the first generation of a cross?

F₁

In a trait with multiple variations (at least two) a heterozygous organism will present the ___________________ gene.

Dominant

What is Mendel's law of equal segregation?

Each parent contributes 1 allele to each offspring with equal frequencies

When there are two possible alleles for a gene random mixing of gametes will result in ___ equally frequent combinations.

4

What is a monohybrid cross?

A cross between two organisms with variation at 1 genetic locus of interest

A species has the following genotypic ratios:

A/A : A/a : a/a

1 : 2 : 1

What will the phenotypic ratio be?

A/A : A/a : a/a

3 : 1

Because A is dominant and will present when homozygous (A/A) and heterozygous (A/a)

What is a test cross?

When an unknown genotype is crossed with a homozygous recessive parent of the same locus (homozygous recessive can only be 1 of 3 genotype combinations)

In a test cross, what will the genotype ratio be if the unknown parent is homozygous dominant? If the unknown parent is heterozygous?

Homozygous dominant: 100% A/a

Heterozygous: 50% A/a: 50% a/a

What will the genotype ratios be in a monohybrid cross?

AA Aa aa

1 : 2 : 1

What is the product (AND) rule?

The probability of independent events occurring together is equal to the product of their individual probabilities.

If you were to toss two coins, what is the probability of both landing on heads?

Probability of heads on coin 1 = 1/2

Probability of heads on coin 2 = 1/2

Probability of heads on both coins = 1/2 * 1/2 = 1/4

If you were to toss two coins, what is the probability of both landing on heads or both landing on tails?

Probability of heads on coin 1 = 1/2

Probability of tails on coin 1 = 1/2

Probability of heads on coin 2 = 1/2

Probability of tails on coin 2 = 1/2

Probability of heads on both coins = 1/2 * 1/2 = 1/4

Probability of tails on both coins = 1/2 * 1/2 = 1/4

Probability of heads or tails on both coins = 1/4 + 1/4 = 1/2

What is the sum (OR) rule?

The probability of either one or the other mutually exclusive events occurring is the sum of individual probabilities of those events

What are the two final outcomes of cellular division?

Mitosis or meiosis

During S-phase of a cell's life, each chromosome ____________________.

duplicates

During S-phase of a cell's life, the number of chromosomes (stays the same/increases/decreases) but the number of sister chromatids (stays the same/increases/decreases).

stays the same, increases (specifically doubles)

Are sister chromatids homologous to each other? Are they identical to each other?

Yes, yes

Are homologous chromosomes identical to each other? Why or why not?

No, they may have different alleles at the same locus. they made code for the same gene but they may also have different alleles.

What are the different stages of M-phase?

Prophase, ...., Anaphase, telophase, ....

Name 3 things that happen during the beggining of interphase to the end of prophase.

DNA replicates then condenses to chromosomes, homologous chromosomes find each other, align, cross over and further condense

How do meiosis and mitosis differ?

Mitosis is for regular cell division, it results in daughter cells that are exact copies.

Meiosis is for gamete creation, it results in a reduction in ploidy with unique genetic combinations in each gamete.

How does genetic exchange occur during meiosis?

Crossing over of chromosomes

What is synapsis?

When all homologous chromosomes are lined up down the middle of a cell during prophase.

What lines up chromosomes down the middle of a cell during prophase 1?

Synaptonemal complex proteins

What do kinetochore proteins do?

They pull chromosomes to opposite poles of a cell during metaphase by attaching spindle fibres to their centromere which then retract

What are microtubules?

Fibres made of tubulin that provide structure to the cell and is involved with mitosis in relation to kinetochores

If an organism has a haploid life cycle what does that mean?

Haploid is the predominant phase for the organism

What is a transient diploid cell? What is it's other name?

A diploid cell formed by fungi to rearrange DNA in times of stress. This cell (aka a meiocyte) undergoes immediate mitosis to form 4 new spore cells

Why do we study lots of haploid life in genetics?

There is no masking of recessive phenotypes. There is no second set of chromosomes that may not be shown, no test crosses are needed to figure out the genotype of an individual.

What is it called when a single nucleotide is changed in DNA?

A single nucleotide polymorphism

What is a "wild-type" allele?

A reference allele for a particular trait, typically chosen because it was the first version of the gene to be sequenced.

If a mutation happens on a promoter region what will happen?

No functional gene product will be had.

What are the three outcomes of a mutation?

A null allele=no functional gene product formed

A leaky allele= some functional gene product is formed

A silent allele= no change in gene product is formed

What happens of a mutation occurs on a protein active site?

A null allele

What happens of a mutation occurs on an intron?

A leaky allele

Are mutant alleles most commonly dominant or recessive?

Recessive

What alleles do the terms haplosufficient and haploinsufficient refer to?

Wild type alleles

If a wild type allele is haplosufficient what does that mean?

A heterozygous (one wild type allele, one mutant allele) individual can produce enough of the wild type allele protein to have the wild type phenotype.

A trait shows if an individual can produce 20 copies of a protein. A heterozygote individual only produces 12 copies of said protein. Is this individual haplosufficient or haploinsufficient?

Haploinsufficient

How are wild type alleles denoted?

With a ⁺ superscript or simply +

___________ names are italicized but not ____________ names.

Gene, protein