Embryogenesis and development

Question 1

What is the difference between determinate and indeterminate cells?

Answer 1

Determinate cells have already been designated to turn into a type of cell

Indeterminate cells haven’t been designated yet, so they have the ability to become any part of the organism

Question 2

What are the characteristics of the morula?

Answer 2

Just a mass of cells the looks like a berry

Question 3

What are the characteristics of the blastula?

Answer 3

A hollow ball of cells with fluid inside, consists of the trophoblast and inner cell mass

The inner cell mass will become the embryo and the trophoblast will become the chorion

Question 4

What are the characteristics of the gastrula?

Answer 4

This is when the three germ layers form

An invagination of the blastula results in one side of the cell caving in until it touches the other side of the cell, making the tube (anus in humans)

Question 5

The ability of one cell to influence nearby cells is called _____

Answer 5

Induction

(cells that create induction are called inducers)

Question 6

The umbilical cord has ___ artery (ies) and ___ vein(s)

Answer 6

2 arteries
1 vein

Question 7

What is the ectoderm and what are some structures it makes up?

Answer 7

The outer most layer

Many “outer” structures:
hair, nails, inner ear, nervous system, eye lens, lower anus, epidermis

Question 8

What is the mesoderm and what are some structures it makes up?

Answer 8

The middle layer

Musculoskeletal system, muscular and connective tissue, layers of digestive and respiratory system, adrenal cortex

Question 9

What is the endoderm and what are some structures it makes up?

Answer 9

The inner most layer

Epithelial lining of digestive and respiratory system, pancreas, thyroid, bladder, distal urinary tract, parts of the liver

Question 10

How does neurulation occur?

Answer 10

The notochord (made of mesoderm) forces the ectoderm to start folding inward, forming the neural folds. Eventually the neural folds become the neural tube

Then the crest cells migrate out and become the peripheral nervous system

Question 11

The notochord is made of _____ while the nervous system is made of ____

Answer 11

Mesoderm

Ectoderm

Question 12

Explain how the three stages of development (specification, determination, differentiation) occur

Answer 12

Specification is reversible and is the point where cells are designated to become a certain type

Determination is irreversible and occurs when the cells have been committed to a certain type, but haven’t undergone any changes yet

Differentiation occurs when the cell changes it’s structure, function and biochemistry to match the cell type

Question 13

Stem cells are those that have not ____

Answer 13

Undergone differentiation, or have the ability to give rise to other cells

Question 14

Totipotent cells

Answer 14

Have the highest level of potency

They’re still in the morula phase, so they can become literally anything

Found from fetal stem cells

Question 15

Pluripotent cells

Answer 15

Have the middle level of potency

They’ve already reached the gastrula stage (differentiated into germ layers) so they can become anything other than placental cells

Question 16

Multipotent cells

Answer 16

Have the lowest level of potency (adult stem cells)

Can become multiple cells within a certain group. The class they’re in has already been decided (ex: immune cells) so they can only be used to create cells of that same category

Question 17

Autocrine

Answer 17

Acts on the same cell that secreted the signal

Question 18

Endocrine

Answer 18

Travels through the blood is reach the target cells

Question 19

Juxtacrine

Answer 19

Acts directly on adjacent cells, does not work through diffusion

Question 20

Paracrine

Answer 20

Works on nearby cells through diffusion

Question 21

What is the difference between complete and incomplete regeneration?

Answer 21

Complete regeneration occurs when the newly formed tissue is identical to the original

Incomplete regeneration occurs when the newly formed tissue is different than the original (ex: scar tissue)

Question 22

Why would cells need to migrate?

Answer 22

So they’re able to reach the necessary location for their designated purpose

Question 23

Senescence

Answer 23

Normal cell aging (this kind of cell will eventually hit apoptosis)

Question 24

In what trimester does most organ development occur?

Answer 24

First

Question 25

The ____ are the last organ to develop

Answer 25

Lungs

Question 26

The foramen ovale and ductus arteriosus shunt blood away from the ____

Answer 26

Lungs

Question 27

What is the purpose of the placenta?

Answer 27

Exchanges gas, nutrients, and waste

Gets necessary things from mother so fetal and maternal blood don’t have to mix (these two cannot mix)

Question 28

The ductus venosus shunts blood away from the ____

Answer 28

Liver

Question 29

The most fetal movement occurs during the ____

Answer 29

Second trimester

Question 30

Antibody transfer occurs at the highest rate in the ____ trimester

Answer 30

Third trimester