Embryo 2 Flashcards

In the uterine tube, capacitated sperm follow chemical signals released by the oocyte and follicular cells. These signals are called:
A. Cleavage
B. Compaction
C. Attractants
D. Blastogenesis

A patient’s sperm reach the oocyte but can’t disperse the corona radiata. Which pair best matches the two acrosomal factors named for dispersing those follicular cells?
A. Hyaluronidase, tubal mucosal enzymes
B. Acrosin, neuraminidase
C. Esterase, hyaluronidase
D. Neuraminidase, attractants

A sperm can reach the zona pellucida but can’t lyse it. Which acrosomal enzyme is listed as the most important for zona pellucida lysis?
A. Hyaluronidase
B. Tubal mucosal enzymes
C. Esterase
D. Acrosin

Besides acrosin, which enzyme is also listed as part of the trio that lyses the zona pellucida?
A. Hyaluronidase
B. Esterase
C. Attractants
D. Early pregnancy factor

Besides acrosin and esterase, which additional enzyme is listed as contributing to zona pellucida lysis?
A. Neuraminidase
B. Hyaluronidase
C. Compaction
D. Blastogenesis

After one sperm successfully passes through the zona pellucida, what change prevents entry of other sperm?
A. Cleavage
B. Compaction
C. Blastocyst cavity formation
D. Zona reaction

The notes describe the zona reaction as oocyte lysosomal enzymes being released into which space?
A. Uterine cavity
B. Blastocoele
C. Perivitelline space
D. Zona surface only

The perivitelline space is the fluid-filled gap between the:
A. Oolemma and zona pellucida
B. Trophoblast and endometrium
C. Embryoblast and hypoblast
D. Morula and blastocoele

During sperm entry, which structure is stated to remain behind while the head and tail enter the oocyte cytoplasm?
A. Sperm tail
B. Sperm plasma membrane
C. Sperm head
D. Sperm pronucleus

A secondary oocyte completes the second meiotic division into a mature oocyte immediately after:
A. Morula formation
B. Zona shedding
C. Blastocoele formation
D. Penetration of the sperm

During fertilization, the nucleus present in either the sperm or egg cell is called a:
A. Pronucleus
B. Ootid
C. Morula
D. Conceptus

A haploid cell formed by meiotic division of a secondary oocyte is termed:
A. Zygote
B. Blastocyst
C. Ootid
D. Trophoblast

The ootid becomes a zygote at the moment:
A. Cleavage begins
B. Pronuclei fuse diploid
C. Zona sheds
D. Hypoblast appears

Crossing over is emphasized because it:
A. Prevents polyspermy
B. Creates blastomeres
C. Forms the zona reaction
D. Shuffles maternal/paternal genes

The value 1.05/1.00 in the notes represents:
A. Females per male
B. Blastomeres per zygote
C. Males per female
D. Morula cells per day

A fertility clinic stores early embryos long-term. The method named in the notes is:
A. Cryopreservation
B. Cleavage
C. Compaction
D. Blastogenesis

The surrogate-mother process in the notes is associated with a higher risk of:
A. Mosaicism
B. Birth defects
C. Zona reaction
D. Blastocoele

The repeated division of a zygote into blastomeres is called:
A. Implantation
B. Blastogenesis
C. Cleavage
D. Zona reaction

Approximately how long after fertilization do zygotes divide into blastomeres (per the notes)?
A. 12 hours
B. 18 hours
C. 6 days
D. 30 hours

After early divisions, blastomeres tightly align into a compact ball. This process is:
A. Compaction
B. Blastogenesis
C. Zona reaction
D. Implantation

Which signaling pathway is listed as essential for segregating embryoblast from trophoblast?
A. Wnt signaling
B. Hippo signaling
C. Hedgehog signaling
D. Notch signaling

A solid, mulberry-shaped ball of 12–32 blastomeres formed 3–4 days after fertilization is a:
A. Blastocyst
B. Conceptus
C. Pronucleus
D. Morula

What is the stated cell-number range for a morula in these notes?
A. 12–32
B. 40–80
C. 80–120
D. 100–300

In the notes, the morula develops about how long after fertilization?
A. 30 hours
B. 6 days
C. 3 days
D. 10 days

A nondisjunction during an early cleavage division yields some normal and some abnormal chromosome counts. This is:
A. Cryopreservation
B. Mosaicism
C. Blastogenesis
D. Compaction

The blastocyst cavity (blastocoele) forms when trophoblast cells:
A. Release lysosomal enzymes
B. Complete meiosis II
C. Fuse pronuclei
D. Pump fluid inward

The notes state the fluid for the blastocystic cavity comes from the:
A. Uterine cavity
B. Perivitelline space
C. Oocyte cytoplasm
D. Zona pellucida

Trophoblasts ultimately give rise to the major part of the:
A. Hypoblast
B. Pronucleus
C. Placenta
D. Oolemma

Early pregnancy factor is described as a:
A. Zona-hardening enzyme
B. Steroid in maternal urine
C. Immunosuppressant serum protein
D. Tubal mucosal enzyme

During the first ~10 days of development (per the notes), pregnancy testing relies on detecting:
A. hCG
B. Early pregnancy factor
C. Acrosin
D. Neuraminidase

The term meaning “development of the blastocyst” is:
A. Blastogenesis
B. Cleavage
C. Compaction
D. Implantation

The term meaning “embryo and its membranes” is:
A. Ootid
B. Morula
C. Pronucleus
D. Conceptus

An early-stage embryo typically 5–7 days post-fertilization with ~100–300 cells is a:
A. Morula
B. Ootid
C. Blastocyst
D. Zygote

Which blastocyst component contains pluripotent cells that give rise to the entire fetal body?
A. Hypoblast
B. Embryoblast
C. Trophoblast
D. Blastocoele

Which outer layer supplies nourishment and later forms the major part of the placenta?
A. Trophoblast
B. Hypoblast
C. Embryoblast
D. Perivitelline space

Shedding of the zona pellucida is important because it permits the blastocyst to:
A. Start crossing over
B. Prevent cleavage
C. Grow rapidly in size
D. Form the ootid

Before implantation, the blastocyst derives nourishment from the:
A. Perivitelline space
B. Zona pellucida
C. Blastocoele
D. Uterine gland

The blastocyst attaches to the endometrial epithelium at about:
A. 6 days
B. 3 days
C. 10 days
D. 30 hours

The fluid-filled cavity within the early embryo is called the:
A. Perivitelline space
B. Morula
C. Conceptus
D. Blastocoele

Which trophoblast layer is described as highly invasive?
A. Hypoblast
B. Embryoblast
C. Syncytiotrophoblast
D. Cytotrophoblast

Around ~7 days, the hypoblast appears on the surface of the embryoblast facing the:
A. Uterine cavity
B. Endometrial epithelium
C. Corona radiata
D. Blastocystic cavity

Removing 1–2 cells from an embryo during IVF for genetic testing is called:
A. Preimplantation genetic diagnosis
B. Blastogenesis
C. Cryopreservation
D. Zona reaction

The notes list the early spontaneous abortion rate as:
A. 5%
B. 15%
C. 45%
D. 80%

The region next to the embryoblast where the invasive trophoblast expands is the:
A. Uterine pole
B. Embryonic pole
C. Ovarian pole
D. Cervical pole

The inner trophoblast layer formed at the embryonic pole is the:
A. Hypoblast
B. Embryoblast
C. Syncytiotrophoblast
D. Cytotrophoblast

The oocyte enzymes that drive the zona reaction are released into the:
A. Perivitelline space
B. Uterine cavity
C. Blastocoele
D. Corona radiata

The ootid forms when the secondary oocyte completes:
A. Mitosis
B. Meiosis II
C. Cleavage
D. Compaction

A mixed population of normal and abnormal blastomeres most directly results from:
A. Failed zona shedding
B. Early cleavage nondisjunction
C. Poor uterine nourishment
D. Failed compaction

1. The fluid-filled cavity within the early embryo is called the:
   A. Perivitelline space
   B. Morula
   C. Conceptus
   D. Blastocoele