GENE 405 Final-- TAMU Mammalian Genetics Fall 2025

All the quizzes and guest speakers

Sex Chromosomes, X Inactivation, and Sex Determination Expert

Dr. Skow

Who said "if in a species hybrid only one sex is inviable or sterile, that sex is more likely to be the heterogametic sex.”

Haldane

Which gene product is known to regulate expression of other genes by bending DNA?

SRY

The mammalian Y chromosome:

1. Contains a testes determining gene

2. Contains 1500 genes mostly unrelated to sex

3. Contains few genes relative to the X chromosome

4. Can condense to form a Barr body in female cells

1. Contains a testes determining gene

3. Contains few genes relative to the X chromosome

The only gene locus known to be transcribed exclusively on the inactivated X-chromosome is:

XIST

Calico cats are almost always female. The rare male calico cats usually have which of the following sex chromosome combinations:

XXY

Mammalian Biodiversity Expert

Dr. Bill Murphy

The concept that DNA substitutions accumulate at an approximately linear rate over time is known as the 'Molecular Clock'. True or False?

True

Anatomical features are more accurate than DNA sequences for determining the phylogenetic relationships of mammalian species. True or False?

False

There are approximately 5,400 species of mammals, divided into three major lineages: monotremes, marsupials, and placentals. True or False?

True

The region of the Earth with the highest density of threatened mammal species is the arctic region. True or False?

False

The massive expansion of the TP53 gene in elephants is hypothesized to provide a genetic mechanism to avoid heart disease. True or False?

False

Molecular Cytogenetics, Chromosomes, and Karyotyping Expert

Dr. Terje Raudsepp

Is there a correlation between genome size and the number of chromosomes?

No

The best time during the mitotic cell cycle for karyotyping and chromosome analysis is:

Metaphase

How many chromatids are present in one chromosome during mitosis metaphase? 

2

Division of nuclear DNA into multiple chromosomes in a cell is:

 A fundamental feature of eukaryotic genomes

A single chromosome during telophase of mitosis contains how many DNA molecules?

1

Animal Models and Disease Expert

Dr. Candice Brinkmeyer-Langford

Mice can be used to model complex phenotypes. T/F?

True

Texas A&M does not require the “3 R’s” (reduce, refine, replace) to be considered by researchers developing Animal Use Protocols. T/F?

False

DMD is a curable disease nowadays. T/F?

False

IACUC stands for “International Animal Care Under Conditions.” T/F?

False

Despite the versatility of mouse models, sometimes mice are not as applicable as dogs. T/F?

True

Conservation Genetics and Genomics Expert

Dr. Sam Stroupe

T/F  There are more bison in private ownership that in public herds.

True

T/F  Yellowstone National Park bison are currently one interbreeding population.

True

T/F Conservation genomics & genetics is limited to only applied research.

False

T/F.  Colossal Biosciences genetically edited over one-hundred genetic variants to “de-extinct” the dire wolf as discussed in Times Magazine.

False

T/F All of the major lineages of bison have an ancestry of hybridization with domestic cattle.

True

Mammalian Development and Stem Cells Expert

Dr. Threadgill oh no this is one of the quizzes i forgot i don’t have access to it!

Comparative, Computational, and Qualitative Genetics and Genomics Expert

Dr. Seabury

Potential origin(s) of CWD may be scrapie (i.e., from sheep), and/or sporadic misfolding of the host prion protein. T/F?

True

CWD is known to infect humans. T/F?

False

Prion codon selection is sufficient to eradicate CWD in farmed white-tailed deer. T/F?

False

The heritability of differences in CWD susceptibility among farmed white-tailed deer is insufficient to reduce the prevalence by selective breeding. T/F?

False

The etiologic agent (causative agent) of CWD is a bacteria. T/F?

False

Assisted Reproductive Tech in Large Animals Expert

Dr. Camilo Hernandez-Aviles oh shit oh fuck i forgot this quiz too

Human Forensic Genomics Expert

Dr. Jennifer Cihlar

The acronym NUMT as discussed in lecture is a nuclear mitochondrial DNA segment. T/F?

True

A CentiMorgan (cM) is a group of SNP markers along a chromosome that are spaced about 100 bp apart. T/F?

False

What information is stored in the CODIS database?

DNA profiles

The mitochondrial genome has a lower mutation rate than the nuclear genome. T/F?

False

Which of the following is true?

1. An individual may have more than one mtDNA haplotype in a single tissue.

2. An individual may exhibit one mtDNA haplotype in one tissue and a different haplotype in another tissue

3. An individual may be heteroplasmic in one tissue sample and homoplasmic in another tissue sample.

All of them

Human Influence on Mammals: Domestication and Selection Expert

Dr. Brian Davis

When scanning genomes for signals of selection, geneticists look for an increase in the divergence between groups (ie. species or breeds) and/or a decrease in genetic diversity within a group. T/F?

True

Neoteny is the characteristic of some domesticated mammals that describes only the change in age at which they are able to reproduce. T/F?

False

Domesticated foxes were produced by mating domestic dogs with wild foxes. T/F?

False

Non-laboratory populations of domesticated mammals make poor models to research the genetics of human disease due to the evolutionary distance between them. T/F?

False

Hybridization between species is not a natural phenomenon, and acts against natural evolutionary processes. T/F?

False

Developmental Genetics Expert

Dr. Riggs

MicroRNAs can function by forming a region of secondary structure that changes the properties of a target DNA sequence.  T/F?

False

Genomic imprinting a process that regulates gene expression and is often related to paternal or maternal inheritance.  T/F?

True

The double muscling phenotype in cattle is caused by a gain of function mutation in the myostatin gene. T/F?

False

HOX genes are unique in that they act to control early embryonic development. T/F?

True

The Callipyge muscle hypertrophy phenotype is caused by a gene located on chromosome 18 in domestic sheep. T/F?

True

Molecular Coat Color Genetics Expert

Dr. Leif Andersson

The first studies of differences in pigment deposition in hair from Dun and non-dun horses was carried out at Texas A&M already in 1930s. T/F?

True

White spotting in dogs is caused by a defect in pigment synthesis.

False

All horses showing the Greying with age phenotype have inherited this mutation from a shared common ancestor.

True

Grey horses becomes white because they have a defect in the migration of pigment cells during fetal development.

False

All pigment cells in mammals originate from the neural crest.

False

Cancer Genetics Expert

Dr. Wyatt nooo i missed this quiz tooo

Biology in Balance: Human Diploid Gene Integrity, Gene Dosage, and Genomic Medicine Expert

Dr. James Lupski

Regarding human medical genetics, Dr. Lupski said: “Base pair changes are not always the answer”. T/F?

True

With the development of RNA vaccines, we now have huge opportunities to treat a large number of diseases and disorders. T/F?

True

The concept of CLAN genomics provides new logic to evaluate the complex architecture of human disease and these concepts align with evolutionary biology and evolutionary medicine. T/F?

True

Clinical personal human genome sequencing from over 3400 patient exomes were recently reported by researchers at Baylor College of Medicine suggesting we are starting to realize “personal genome medicine”. T/F?

True

Dr. Lupski’s interest in medical genetics is far reaching and primarily focused on copy number variants, duplication and deletions events, de novo mutations and multilocus genomic variation. T/F?

True

True or False: Nearly all cancers are due to some type of genetic mutation

True

True or False: Open chromatin (euchromatin) is associated with active gene transcription

True

True or False: TP53 mutations are found in less than 10% of all human cancers

False

True or False: BRCA mutated cancers are susceptible to olaparib

True

True or False: Triple negative breast cancer has a better overall prognosis when compared to HER2+ breast cancers

False