Dear students
You will work in a group of five students to complete this assignment. Answers must be submitted
through e-learning one student from each group is satisfactory to do submission, thus no need for all
group members to submit assignment. Make sure the names of all students in the group are included in
submitted answers. The assignment must be submitted no later than March 20, 2022
***Please submit the assignment as online text submission, with no attachment.
Visit the link below, then watch, think and answer the following questions
https://www.youtube.com/watch?v=izOa3-AX8zQ
Questions
Q1. Which of the following statements are true, and which are false? (4 MARKS, 1 mark EACH)
A. In the early stages of cell division, the number of cells and their size increase.
B. Implantation occurs by means of adherence of the zona pellucida to the uterine epithelium
C. Most of the neural deformities originate at the end of fetal life and pregnancy
D. The morula enters the uterine cavity on the 5-7th day after fertilization
Q2. List the main parts of the blastocyst and the structures derived from each part? (3 MARKS)
Q3. What does gastrulation mean? give examples for each of its products. (1 MARK)
Q4. Describe the placental function as an exchange agent including the name of structure/s that help in
completing the transfusion task (2 MARKS)
Q1)
A. F
b. T
c. F
d. F
Q2) Blastocyst consists of the Embryoblast which is the initial structure of the human, and the
trophoblast which is the origin if the placenta and the membranes.
Trophoblast fuse with endometrium to form a central trophoblast cell that will nourish the embryo.
Hypoblast, and epiblast arise from the embryoblast.
The embryo burrows further into the endometrium.
Amniotic cavity is formed as well as yok sac thus is formed from the hypoblast.
Trophoblast increases in size while the amniotic cavity and the yok sac remain relatively small which will
make chorionic cavity and body stalk rise.
Q3) The process where the primitive streak and node form three germ layers; endoderm, ectoderm, and
mesoderm, and eventually will differentiate into different tissues and organs.
Endoderm: interior lining of organs
Ectoderm: nervous system, and skin.
Mesoderm: blood vessels, bones, and muscles.
Q4) The placenta is accountable for the exchange of substances among mother and fetus with the assist
of the chorionic villi and umbilical cord. Oxygen-rich and nutrient-rich maternal blood travels through the
arteries to the intervital space, while veins carry away the oxygen-poor and nutrient-poor blood with the help
of chorionic villi by extracting the oxygen and the necessary nutrients from the mother’s blood. Nutrients
include, carbohydrates, amino acids, fats, vitamins, and iron, Oxygen and nutrient are then transported
to the fetus via the veins with the help of the umbilical cord. However, waste products also reach the
villi via the arteries to allow the fetus to release its waste products such as carbon dioxide and urea into
the maternal blood.