Genetics Exam 1

Name the three main branches of modern genetics.

Transmission (Mendelian), evolutionary, and molecular.

Transmission (Mendelian genetics)

The study of the transmission of traits in successive generations.

Evolutionary

The study of the genetic relationships between organisms and the evolution of genes and genomes

Molecular

The study of inheritance and variation of Nucleic acids, proteins, and genomes.

Of the 3 branches of modern genetics which is the oldest?

Transmission genetics

What is the cell theory?

All cells come from pre existing cells

What year was the cell theory postulated and by who?

1855 and Virchow

What is modern synthesis and when did it occur?

Unified theory of evolution and between 1900-1940

The 4 evolutionary processes

Natural selection, migration, mutation, and genetic drift

When was PCR invented?

1985

4 common qualities shared by many model organisms

Cheap to raise, few ethical constraints, lots of variation, and short life cycle

How big is the human genome?

3-3.2 billion base pairs

How big is the fruit fly genome?

140-180 megabases

How big are bacterial cells?

1-10 um

How big are eukaryotic cells?

10-100 um

3 differences between the DNA in bacterial cells and eukaryotic cells

Eukaryotic have multiple and linear chromosomes, membrane bound organelles, and a cytoskeleton

Chromosome

An individual long molecule of dna and complexed proteins

Do bacteria cells have just one proteins?

No

What is the product level of diploid cells?

2N

Replicated chromosomes consist of?

Two identical sister chromatids

What are sister chromatids held together by?

Centromere

Do homologous chromosomes carry the same genes?

If a cell has two versions of each chromosome it is a ____ cell

Diploid

If a cell has one version of each chromosome, it is a ___ cell

Haploid

How would you describe the chromosomes in a human muscle cell?

2N=46

How would you describe the chromosomes in a human egg cell?

1N=23

What phase does DNA replication occur?

S phase

What occurs at M phase?

Cell division

Growth factors and other chemical signals stimulate the production of proteins called?

Cyclins

During mitosis are sister chromatids or chromosomes pulled apart?

The protein ___ localized between sister chromatids and holds them together

Cohesion

Protein __ hydrolysis cohesion releasing chromatids during anaphase

Separase

What causes genetic variation in meiosis?

Recombination and independent assortment

What phase do homologous chromosomes pair?

Prophase 1

What phase does crossing over occur?

Prophase 1

What phase does independent assortment of homologous chromosomes occur?

Anaphase 1

What phase does the segregation of sister chromatids occur in meiosis?

Anaphase 2

What is Mendel first law?

The law of segregation

What is Mendel second law?

The law of independent assortment

What is crossing over?

Combinations of alleles of different genes on the same chromosome

What is independent assortment?

Combinations of alleles from different genes from different chromosomes.

F2 ratio

3:1

dihybrid ratio

9:3:3:1 phenotype

Linked genes

Genes close together on same chromosome

What is the measure of the expected number of crossovers between two loci?

Centimorgan

What is sexually monomorphic?

Both pollen and seed producing parts

What type of dominance: heterozygote has phenotype identical to homozygous for one allele?

Complete dominance

What type of dominance: phenotype of heterozygote is intermediate between two homozygous phenotypes

Incomplete dominance

What type of dominance: heterozygote expresses phenotypes of both alleles

Codominance

What type of dominance: phenotype of heterozygote is more extreme than or novel compared to that of either homozygote

Overdominance

Defined as one gene having multiple phenotypic effects

Pleiotropy

Allele of one gene impacts the expression of alleles at another gene

Epistasis

Genetic element transferred from mitochondria to nuclear genome

Numt

Genetic element transferred from chloroplasts to nuclear genome

Nupt