Miscellaneous
What is the largest state in Mexico by land area?
a) Sonora
b) Chihuahua
c) Coahuila
d) Durango
b) Chihuahua
Which germ layer primarily gives rise to the central nervous system?
a) Endoderm
b) Mesoderm
c) Ectoderm
d) Mesenchyme
c) Ectoderm
Which of the following neck muscles is innervated by the cervical plexus and not by the accessory nerve (XI)?
a) Sternocleidomastoid
b) Trapezius
c) Omohyoid
d) Splenius capitis
c) Omohyoid
Which of the following structures is NOT considered a membrane-bound organelle?
a) Mitochondrion
b) Endoplasmic reticulum
c) Ribosome
d) Golgi apparatus
c) Ribosome
Which of the following amino acids contains an imidazole group in its side chain and can act as a proton donor or acceptor?
a) Histidine
b) Arginine
c) Lysine
d) Tyrosine
a) Histidine
Which Mexican holiday is celebrated on November 1st and 2nd to honor the dead?
a) Independence Day
b) Day of the Dead
c) Revolution Day
d) Holy Week
Day of the dead
During the third week of development, which structure is fundamental for the induction of the notochord?
a) Primitive streak
b) Neural crest
c) Yolk sac
d) Chorion
a) Primitive streak
The suboccipital triangle contains several important structures. Which of the following does NOT pass through this triangle?
a) Vertebral artery
b) Suboccipital nerve (C1)
c) Greater occipital nerve (C2)
d) Internal jugular vein
d) Internal jugular vein
The nucleolus is characterized by:
a) Being surrounded by a double nuclear membrane
b) Being the main site of ribosome synthesis
c) Containing only heterochromatic DNA
d) Participating in cellular digestion
b) Being the main site of ribosome synthesis
In aqueous solutions, the H⁺ ion is primarily stabilized by:
a) Disulfide bridges
b) Hydrogen bonding with water molecules
c) Hydrophobic interactions
d) Peptide bonds
b) Hydrogen bonding with water molecules
Who was the first emperor of the Roman Empire?
a) Julius Caesar
b) Augustus
c) Nero
d) Caligula
b) Augustus
Closure of the cranial neuropore occurs approximately on:
a) Day 18
b) Day 22
c) Day 25
d) Day 28
c) Day 25
(Extremely Difficult):
Regarding the cervical vertebrae, which of the following statements about the transverse foramen is correct?
a) It only allows the vertebral artery to pass in C1–C6.
b) The vertebral artery passes through all transverse foramina except C7.
c) It contains only accessory veins.
d) The spinal nerve passes through this foramen in C1–C6.
b) The vertebral artery passes through all transverse foramina except C7
Which of the following epithelial tissues is specialized for absorption and is mainly found in the small intestine?
a) Simple squamous epithelium
b) Simple cuboidal epithelium
c) Simple columnar epithelium with microvilli
d) Transitional epithelium
c) Simple columnar epithelium with microvilli
The isoelectric point (pI) of a neutral amino acid is generally calculated as:
a) The average of the pKa values of the amino and carboxyl groups
b) The average of all side chain pKa values
c) The sum of all pKa values
d) The difference between the amino and carboxyl pKa values
a) The average of the pKa values of the amino and carboxyl groups
What is the hardest naturally occurring mineral on Earth?
a) Quartz
b) Diamond
c) Topaz
d) Corundum
b) Diamond
Which of the following derivatives arises directly from the intermediate mesoderm?
a) Skeletal muscle
b) Urinary system
c) Epidermis
d) Axial skeleton
b) Urinary system
Regarding the nuchal ligament, what is its main function besides serving as a muscular attachment?
a) Limit excessive extension of the head
b) Maintain cervical lordotic curvature
c) Connect the transverse processes of C1–C7
d) Prevent lateral rotation of the cervical spine
a) Limit excessive extension of the head
Regarding cell junctions, which statement is correct?
a) Desmosomes connect actin filaments between cells.
b) Hemidesmosomes connect the cell to the basal lamina.
c) Tight junctions allow free passage of solutes between cells.
d) Gap junctions connect the nucleus of two adjacent cells.
b) Hemidesmosomes connect the cell to the basal lamina
In the phosphate buffer system (H₂PO₄⁻/HPO₄²⁻), what happens when HCl is added to the solution?
a) The H⁺ binds to HPO₄²⁻ forming H₂PO₄⁻
b) H⁺ increases the pH significantly
c) HCl decomposes into water and gas
d) No reaction occurs due to system neutrality
a) The H⁺ binds to HPO₄²⁻ forming H₂PO₄⁻
In 1994, who performed the backing vocals on Transmetal's album El Infierno de Dante, produced by Scott Burns at Morrisound, which almost sold 100,000 copies?
a) Alex Lora
b) Chuck Shuldiner
c) Dante Alighieri
d) Glen Benton
d) Glen Benton
In the third week, the lateral mesoderm splits into two layers. Which of the following is the correct combination of their main derivatives?
a) Somatic layer → axial skeleton; Splanchnic layer → dermis
b) Somatic layer → body wall; Splanchnic layer → primitive gut and mesenteries
c) Somatic layer → neural tube; Splanchnic layer → skeletal muscle
d) Somatic layer → peripheral nervous system; Splanchnic layer → lymphatic system
b) Somatic layer → body wall; Splanchnic layer → primitive gut and mesenteries
Regarding the deep back muscles (erector spinae), which of the following statements is correct?
a) The thoracic iliocostalis originates from the thoracolumbar fascia and inserts on the upper ribs.
b) The longissimus capitis inserts on the mastoid process and originates from the thoracic transverse processes.
c) Thoracic semispinalis muscles do not extend into the cervical region.
d) Interspinales are more prominent in the thoracic region than in the lumbar region.
b) The longissimus capitis inserts on the mastoid process and originates from the thoracic transverse processes
In the nucleus, facultative heterochromatin is characterized by:
a) Being permanently inactive and always condensed
b) Being able to alternate between active and inactive states depending on the cell
c) Containing only RNA
d) Being absent in eukaryotic cells
b) Being able to alternate between active and inactive states depending on the cell
For an amino acid with an acidic side chain like glutamic acid, what happens to its net charge when the pH of the solution equals the pKa of the side chain?
a) The side chain is 50% protonated and 50% deprotonated
b) The side chain is fully protonated
c) The side chain is fully deprotonated
d) The net charge is zero
a) The side chain is 50% protonated and 50% deprotonated