More Genomics
True or False: Comparative genomics is only useful for studying closely related species and cannot provide insights into distantly related organisms.
False
The process by which cells with the same genome become specialized through selective gene expression.
Cell differentiation
True or False: at fertilization an egg and sperm fuse to form a single totipotent cell which can become any cell type including the placenta
True
___________ is when tumor cells travel to other parts of the body and establish a secondary tumor.
Is the following trait quantitative or qualitative: Presence of horns in a goats
Qualitative (present or absent)
True or False: The tuberculosis vaccine is a type of attenuated vaccine that is made from killed bacteria samples.
False: attenuated vaccines are made from live virus or bacteria that cannot reproduce but still cause a mild form of the disease
Embryonic cells are considered _________, meaning they can form any of the 200+ cell types in an adult other than placenta.
Pluripotent
Genes in different species that evolved from a common ancestral gene and often retain similar functions across species.
Orthologs
Broadly, what is cancer caused by?
Defects in cell division related to DNA
This genetic field studies traits controlled by many genes and influenced by the environment, such as height or crop yield.
Quantitative Genetics
A researcher suspects a gene is involved in cancer development so they design a study to mutate the gene in mice using CRISPR and will document the effect on the mouse’s phenotype. What type of genetic study is this?
Reverse genetic study (start with a known gene and observe the changes in phenotype when the gene’s expression or sequence is changed)
A group of highly conserved genes that control body patterning and segment identity along the anterior–posterior axis.
Hox (homeobox) genes
This developmental phenotype occurs when loss of posterior Hox gene function causes body segments to adopt more anterior identities.
Anterior transformation
List two examples of gene types in which mutations could contribute to cancer development?
Cell division regulation, cell cycle regulation, chromosome segregation genes, DNA repair regulation, telomerase regulation, and genes that promote growth, vascularization, and the spread of tumors
In a sheep study, a rare coat color anomaly appeared only after a critical number of risk alleles were inherited—sheep either had the anomaly or they didn't. Which type of quantitative characteristic was being measured?
Threshold Characteristic
The goal of functional genomic research is to understand the… (list the three “omes”)
Transcriptome, Epigenome, Proteome
In a veterinary clinic, a dog presented with extra toes and misaligned limbs. Subsequent genetic testing pinpointed errors in the gene cluster responsible for limb patterning. What cluster of genes was likely mutated? (Be specific)
HOXD genes (or Homeotic (Hox) selector genes)
Name the 3 germ layers a fertilized zygote differentiates into.
Ectoderm (outer), Mesoderm (middle), Endoderm (inner)
What are the two types of genes that when mutated are involved in dysregulation of cell division?
Proto-oncogenes → Oncogenes - stimulatory, mutated copies of proto-oncogenes that are hyperactive
Tumor suppressor genes - regulate cell growth and prevent uncontrolled cell division
Write out the equation for phenotypic variance AND indicate what each Letter means
Vp = Vg+ Ve + Vge
Vp = phenotypic variance
Vg = genotypic variance
Ve = Environmental variance
Vge = genetic/environmental interaction
Transcriptomics encompasses both bulk and single-cell RNA sequencing. True or false: Bulk RNA sequencing is primarily used to characterize complex tissue heterogeneity, identify rare cell types, or map cell-specific pathways.
False: single-RNA sequencing; Bulk RNA sequencing is for large sample sizes or low input samples
This developmental transition marks the shift from maternal to embryonic control of gene expression and is associated with widespread chromatin remodeling and activation of the zygotic genome.
Zygotic genome activation (ZGA)/MZT
This occurs during epigenetic reprogramming in early embryogenesis during the pre-implantation stages. Certain regions are spared during this process, which are maintained via DNMT1 activity.
Global demethylation
__________ contributes to cancer by mutating and rearranging host genes that then contribute to viral proliferation, or by altering the expression of host genes
Viruses
In a study of fin length in a particular fish species, researchers measured a total phenotypic variance of 80 mm². They determined that the additive genetic variance was 20 mm², the dominance variance was 10 mm², and the epistatic variance was 5 mm².
Question: Calculate the broad-sense heritability (H²) for fin length in this fish population.
Broad-sense heritability (H2 = VG/VP)
H² = (Additive Variance + Dominance Variance + Epistatic Variance) / Total Phenotypic Variance
H² = (20 + 10 + 5) / 80 = 35 / 80 = 0.4375 (or approximately 44%).