1.
The developing human is called embryo?
Correct Answer
C. Until the End of 8th week
Explanation
9th week until birth = fetus
2.
Fertilization usually takes place in?
Correct Answer
C. Ampulla of the uterine tube
Explanation
Fertilization usually takes place in the ampulla of the uterine tube. This is because the ampulla provides the optimal environment for the sperm and egg to meet and fuse. The ampulla is the widest and longest part of the uterine tube, allowing for the highest chance of successful fertilization. Once fertilization occurs in the ampulla, the resulting zygote will then travel to the uterus for implantation and further development.
3.
All of these cause variations in human species except?
Correct Answer
D. Blastulauion
Explanation
Blastulation is the process by which a blastula is formed during embryonic development. It is a stage in the early development of an embryo and does not cause variations in the human species. Mingling, mutations, and crossing-over, on the other hand, can cause variations in the human species by introducing new genetic material or altering existing genetic material.
4.
After the fast process of cleavage (cell division) of the zygote, its size increases
Correct Answer
D. Size doesn't change
Explanation
Note:Blastomere sizes decrease with each division
5.
Zona pellucida dissappers
Correct Answer
C. 6 DAF
Explanation
The zona pellucida is a thick glycoprotein layer that surrounds the oocyte and plays a critical role in fertilization. It is initially present but gradually disappears as the oocyte matures. The process of zona pellucida disappearance is known as zona hatching. In this case, the correct answer is 6 DAF (days after fertilization), indicating that the zona pellucida disappears on the 6th day after fertilization.
6.
Implantation occurs in which part of the uterus?
Correct Answer
E. Two answers ar correct
Explanation
Implantation can occur in two parts of the uterus, namely the fundus and the body. The fundus refers to the upper part of the uterus, while the body refers to the main central part of the uterus. Implantation is the process where a fertilized egg attaches itself to the lining of the uterus, and it typically occurs in the fundus or body of the uterus. The other options, the uterine tube and cervix, are not correct as implantation does not occur in these parts of the reproductive system.
7.
During the first 6 days after fertilization, the embryo is nourished by?
Correct Answer
C. Secretions from mucosa of uterin tube and uteres
Explanation
During the first 6 days after fertilization, the embryo is nourished by secretions from the mucosa of the uterine tube and uterus. These secretions provide essential nutrients and support for the developing embryo before it implants into the uterine lining. The embryo relies on these secretions for its early growth and development until the placenta is formed, which takes place after the first 6 days. Embryonic vessels and the placenta do not play a role in nourishing the embryo during this early stage.
8.
The process in which the bilaminar disc transforms into a trilaminar disc is called?
Correct Answer
A. Gastrulation
Explanation
Gastrulation is the process in which the bilaminar disc, consisting of the epiblast and hypoblast, transforms into a trilaminar disc by the formation of three primary germ layers: ectoderm, mesoderm, and endoderm. This process is essential for the development of the embryo and the formation of various tissues and organs. Neuralation refers specifically to the formation of the neural tube, which occurs during gastrulation. Blastulation is the formation of the blastula, a hollow ball of cells, which precedes gastrulation. "Smthtion" is not a recognized term in embryology.
9.
You're awesome for reaching this far, would u like a bonus mark?
Correct Answer
C. Yes
Explanation
The correct answer is "Yes" because the question asks if the person would like a bonus mark, and the options given are "Yes" and "No". Since the person wants a bonus mark, they would choose "Yes".
10.
Cells derived from the hypoblast.
Correct Answer
A. Form the exocoelomic membrane
Explanation
The cells derived from the hypoblast form the exocoelomic membrane. The exocoelomic membrane is a thin layer of cells that lines the outer surface of the amniotic cavity and covers the developing embryo. It is involved in various functions such as nutrient exchange and waste removal during early embryonic development. These cells play a crucial role in the formation and maintenance of the exocoelomic membrane.
11.
The extraembryonic coelom surrounds the amnion and embellished vesicle whole.
Correct Answer
B. False
Explanation
Remember, it surrounds the amnion and umbilical vesicle except at the connecting stalk
12.
Which of these covers the umbilical vesicle after the formation of the chronic sac? (late 2nd week)
Correct Answer
A. Extraembryonic splanchnic mesoderm
Explanation
After the formation of the chorionic sac, the umbilical vesicle is covered by the extraembryonic splanchnic mesoderm. This layer of mesoderm surrounds the umbilical vesicle and is derived from the extraembryonic mesoderm. It plays a crucial role in the development of the umbilical cord and provides support and nourishment to the developing embryo. The definitive mesoderm, ectoderm, and extraembryonic somatic mesoderm are not involved in covering the umbilical vesicle at this stage of development.
13.
The future site of the mouth?
Correct Answer
D. Perechordal plate
Explanation
The correct answer is Perechordal plate. The perechordal plate is a structure that forms during embryonic development and is located at the future site of the mouth. It plays a crucial role in the formation of the face and oral cavity. The neural groove is a depression in the ectoderm that eventually forms the neural tube, not the mouth. The tail of the embryo is unrelated to the mouth development. "Idk" is not a valid answer.
14.
The mother usually notices her pregnancy after?
Correct Answer
C. 3 weeks
Explanation
Because the mother notices a missed female period
15.
The cranial end of the primitive streak enlarges to form the primitive node.
Correct Answer
A. True
Explanation
The primitive streak is a structure that forms during early embryonic development. It is a thickened band of cells that runs along the midline of the embryo. The cranial end of the primitive streak refers to the front end, or head region, of the streak. This region enlarges and forms a structure called the primitive node. The primitive node plays a crucial role in organizing the development of the embryo, including the formation of the three germ layers and the establishment of the body axis. Therefore, the statement that the cranial end of the primitive streak enlarges to form the primitive node is true.
16.
One of these structures plays no role in the formation of any part of the developing embryo.
Correct Answer
B. Hypoblast
Explanation
The hypoblast is a structure that does not play a role in the formation of any part of the developing embryo. It is a layer of cells located in the blastocyst that eventually gives rise to the extraembryonic endoderm, which forms the yolk sac. The epiblast, mesoderm, and ectoderm are all essential in the formation of different parts of the embryo. The epiblast gives rise to the three germ layers, including the ectoderm, mesoderm, and endoderm, which form various tissues and organs in the developing embryo. Therefore, the hypoblast is the correct answer as it does not contribute to the formation of any part of the developing embryo.
17.
The process remains as the nucleus pulposus of intervertebral discs.
Correct Answer
B. Notochord
Explanation
The correct answer is notochord. The notochord is a flexible rod-like structure that forms during embryonic development and serves as the precursor to the spinal column in vertebrates. It provides support and stability to the developing embryo and eventually develops into the nucleus pulposus, which is the gel-like substance found in the center of intervertebral discs. This process remains consistent throughout development, making the notochord the correct answer.
18.
The neural folds fuse with each other, converting the neural plate into the?
Correct Answer
D. Neural tube
Explanation
During embryonic development, the neural folds, which are formed by the neural plate, eventually fuse together in the midline. This fusion results in the formation of a hollow structure known as the neural tube. The neural tube gives rise to the central nervous system (CNS), which includes the brain and spinal cord. Therefore, the correct answer is the neural tube.
19.
Which of These methods can be used to determine the age of embryo?
Correct Answer
D. All of the above
Explanation
All of the above methods can be used to determine the age of an embryo. Somite prominent elevations, biparietal distance, and crown-rump length are all measurements that can be taken during the development of an embryo to estimate its age. These measurements are commonly used in obstetrics and ultrasound examinations to assess the growth and development of the fetus.
20.
Exposure of embryo to teratogens leads to the highest risk of congenital animalities in which period?
Correct Answer
A. 4th-8th week
Explanation
During the 4th-8th week of pregnancy, the embryo undergoes critical stages of development, known as organogenesis. This is the period when the major organs and body structures are forming. If the embryo is exposed to teratogens (substances that can cause birth defects), it is most vulnerable during this time. Teratogens can disrupt the normal development of organs and tissues, leading to congenital abnormalities in the baby. Therefore, the highest risk of congenital abnormalities occurs during the 4th-8th week of pregnancy.
21.
MRI scans on the fetus are dangerous due to radiation.
Correct Answer
B. False
Explanation
Remember,CT scans are the dangerous ones
22.
The allantois Is involved in the formation of the urinary bladder.
Correct Answer
A. True
Explanation
Also blood
23.
All of these are derived from the mesoderm except
Correct Answer
C. Adrenal gland medulla
Explanation
Ectoderm=adrenal medulla
Mesoderm=adrenal cortex