WEEK 1 OF HUMAN EMBRYONIC DEVELOPMENT

Question 1

What is the process called when a sperm fertilizes an egg?

Answer 1

Fertilization

Question 2

True or False: The zygote is the first cell formed after fertilization.

Answer 2

True

Question 3

What is the name of the structure formed by the division of the zygote?

Answer 3

Blastomeres

Question 4

During which phase does the zygote undergo cleavage?

Answer 4

Early development phase

Question 5

Fill in the blank: The process of cell division that occurs in the early stages of embryonic development is called __________.

Answer 5

Cleavage

Question 6

What is the name of the hollow ball of cells formed by cleavage?

Answer 6

Blastocyst

Question 7

True or False: The blastocyst consists of two layers: the inner cell mass and the trophoblast.

Answer 7

True

Question 8

What does the inner cell mass of the blastocyst develop into?

Answer 8

Embryo

Question 9

What is the function of the trophoblast?

Answer 9

To form the placenta

Question 10

How many days after fertilization does the blastocyst implant into the uterine wall?

Answer 10

Approximately 6 days

Question 11

Multiple choice: What is the term for the process where the blastocyst attaches to the uterine lining? A) Gastrulation B) Implantation C) Cleavage D) Fertilization

Answer 11

B) Implantation

Question 12

What hormone is produced by the trophoblast to maintain the uterine lining?

Answer 12

Human chorionic gonadotropin (hCG)

Question 13

True or False: The first week of embryonic development ends with the formation of the placenta.

Answer 13

False

Question 14

What is the main event occurring during the first week of embryonic development?

Answer 14

Formation of the blastocyst and implantation

Question 15

Fill in the blank: The zona pellucida is a protective layer surrounding the __________.

Answer 15

Oocyte

Question 16

What happens to the zona pellucida after fertilization?

Answer 16

It hardens to prevent additional sperm from entering.

Question 17

What is the term for the initial stage of cell division after fertilization?

Answer 17

Cleavage stage

Question 18

True or False: The cleavage stage involves the increase in the size of the zygote.

Answer 18

False

Question 19

What structure begins to form as the inner cell mass differentiates during the first week?

Answer 19

Embryonic disc

Question 20

What is the primary function of the blastocyst during implantation?

Answer 20

To embed itself in the uterine lining

Question 21

Multiple choice: Which of the following is NOT a part of the blastocyst? A) Trophoblast B) Inner cell mass C) Amniotic sac D) Blastocoel

Answer 21

C) Amniotic sac

Question 22

What is the role of the amniotic cavity that develops in the second week?

Answer 22

To protect the developing embryo

Question 23

True or False: The first week of embryonic development includes the formation of all major organ systems.

Answer 23

False

Question 24

What key event signifies the transition from a zygote to a blastocyst?

Answer 24

The formation of a fluid-filled cavity

Question 25

Fill in the blank: The stage of development that occurs before implantation is called the __________ stage.

Answer 25

Pre-implantation

Question 26

What is the main purpose of the trophoblast during the first week?

Answer 26

To facilitate implantation and form the placenta