Micro- embryology and gametogenesis

Question 1

Trace the development of a zygote through gastrulation

Answer 1

Form a single cell zygote, compact mass of cells morula, fluid filled cysts with cells at the periphery Blastula, Bilaminar disk Early gastrula, Trilaminar disk to tube shape Late gastrula.

Question 2

This is the nucleus of sperm of egg cell during the process of fertilization. These do not fuse but however their genetic material does. These will form the singl diplod nucleus resulting in an embryo. The zygote will contain male and female ___.

Answer 2

male and female pronuclei

Question 3

This is the division of cells in the early embryo. The zygote undergoes rapid cell cycles with no significant growth producing clusters of cells.

Answer 3

This is known as cleavage

Question 4

This is A cluster of blastomeres. The zona pellucida is still intact in this structure.

Answer 4

Morula

Question 5

In this structure the cavity begins to form , inner and outer masses are present.

Answer 5

blastocyst

Question 6

This forms the embryo

Answer 6

inner cell mass

Question 7

This forms the dorsal layer of the embryo

Answer 7

epiblast

Question 8

This forms the ventral layer of the embryo

Answer 8

hyoblast

Question 9

This is an outer cell mass that forms the placenta

Answer 9

trophoblast

Question 10

Formation of three germ layers and the primitive axial organs (___ ____,____ ____,_____, _______ ____) Begins with the formation of the primitive streak in the epiblast (cranial and caudal aspects are now established.

Answer 10

neural tube, notochord, somites, primitive gut. This is known as gastrulation

Question 11

Epithelium, nervous tissue and neural crest cell is found in?

Answer 11

ectoderm

Question 12

connective tissue, muscle, endothelium, mesothelium, urogenital system. This area is formed from cells migrating from the primitive streak

Answer 12

mesoderm

Question 13

This is the epithelium of digestive tract and respiratory system

Answer 13

endoderm

Question 14

Any agent or factor that can cause congenital anomalies in an embryo or fetus that is caused by; genetic factors , radiation, hormones, chemical agents, and infectous agents

Answer 14

Teratogen

Question 15

Parent of all cells, differentiate into all cells

Answer 15

totipotent

Question 16

differentiate into specific cells

Answer 16

pluripotent /multipotent

Question 17

differentiate into a specific cell line (bone marrow and blood cells)

Answer 17

unipotent

Question 18

When organs begin to form and migrate to specific sites

Answer 18

migration

Question 19

this is the process by which an immature cell reaches maturity

Answer 19

differentiation

Question 20

The “skeleton” or threshold of all organs (structures that keep the organ in place)

Answer 20

mesenchyme

Question 21

List the 4 divisions of mesoderm based on their position in the embryo.

Answer 21

Axial
paraxial
intermediate and lateral plate

Question 22

4 divisions of mesoderm : The formation of the notochord

Answer 22

Axial

Question 23

4 divisions of mesoderm:Somites!! somite-division of animal’s body giving rise to muscle, cartilage, tendons, and dermis (limbs and vertebrae).
Dermatome=?
Myotome=?
Sclerotome=?

Answer 23

Paraxial
dermis
muscle
cartilage and splanchnic mesoderms

Question 24

4 divisions of mesoderm:genital and urinary systems

Answer 24

intermediate

Question 25

4 divisions of mesoderm:somatic and splanchnic mesoderms

Answer 25

lateral plate

Question 26

Predifferentiation stage: embryo dies Organogenesis stage: structural defects Fetal growth stage : affects functional maturation These are examples of?

Answer 26

Teratogenic influences on development

Question 27

cleft palate, umbilical hernia, spina bifida,atrial septal defect are all examples of?

Answer 27

common developmental anomalies

Question 28

Abnormalities of testicular descent: This is when the testis fail to descend into the scrotum. This is inherited as a sex-limited autosomal recessive trait.

Answer 28

cryptorchidism

Question 29

Cryptorchidism can be unilateral= | or bilateral=

Answer 29

unilateral=fertile | bilateral=sterile, but has normal sexual behavior

Question 30

This is another abnormality of testicular descent and is a type of iguinal____ causing a congenital weakness in the abdominal wall.

Answer 30

hernia, Scrotal hernia

Question 31

gametogenesis: Primitive sex cells: ______,___- have complete DNA compliment. ____ results in more of these primitive sex cells

Answer 31

spermatogonia and oogonia. MITOSIS

Question 32

____ AND _____ Meiosis- purpose is to insure variation and provide____ of chromosomes (____ number) both in male (1N) and female (1N) sex cells= (____)

Answer 32

spermatocyte, oocyte, 1/2, haploid, gametes

Question 33

The joining of sex cells is____ which creates a ____, restores the DNA complement (2N) and initiates ___

Answer 33

fertilization, zygote, cleavage

Question 34

This process results in the formation of 2 daughter cells each having ______(2N) set of chromosomes, This is the same # of chromosomes as in the mother cell

Answer 34

DIPLOID- Mitosis

Question 35

This process has 2____ divisions. This results in daughter cells which have half the parental number of chromosomes (____) 1N. These are called gametes.

Answer 35

meiotic ,HAPLOID

Question 36

GAMETES ARE ____

Answer 36

HAPLOID

Question 37

Goals of ____: reduction of diploid set chromosomes into haploid gametes.

Answer 37

meiosis

Question 38

In meiosis there is an exchange of genetic material between male female chromatids in _____of meiosis I (crossing over).

Answer 38

PROPHASE

Question 39

Meiosis: the mixing from prophase results in ___ ___ cells with ____ different genetic makeups

Answer 39

4 daughter cells with 4 different genetic makeups

Question 40

Common features of gametogenesis: oogenesis and spermatogenesis have features in common, both involve: ___ of spermatogonia and oogonia. The process of ____. Extensive morphological differentiation. And incapacity of surviving for very long if____ does not occur.

Answer 40

multiplication. meiosis. fertilization.

Question 41

Basic plan of oogenesis: 1.this occurs in the____. oogonia -prenatal mitosis and differentiation.

Answer 41

ovary

Question 42

2.All are ____ oocytes(4N) arrested in meiosis I until puberty when _____ occcurs. At olvulation _____ _ is completed except for dogs and mares (these ovulate primary oocytes)

Answer 42

primary oocytes, FOLLICULOGENESIS, meiosis I

Question 43

3. In uterine tube ___ oocyte(2N) awaits fertilization . (1st polar body present) . Meiosis II is completed when ____ ____ . The result is an ___ (1N) and a 2nd polar body (1N).

Answer 43

secondary oocyte, sperm contact, ovum

Question 44

What is the result from Meiosis II?

Answer 44

an ovum (1N) and a 2nd polar body (1N)

Question 45

Folliculogenesis: Primordal follicles = ___ __ : oocyte I and single layer of _____ follicular cells

Answer 45

resting follicles, squamous

Question 46

Activated or growing follicles; zona pellucida forms. These are known as ?

Answer 46

primary follicles

Question 47

one antrum containing liquor follicle, they have eccentric cumulus oophorus, containing a PRIMARY OOCYTE

Answer 47

Tertiary mature (Graafian) follicle

Question 48

These follicles are secretory = antral follicles, fluid filled spaces are formed among the granulosa cells

Answer 48

secondary follicles

Question 49

This is when the follicular space fills with blood and clots . This bloody body will be replaced by infiltrating luteal cells to become the___ ___

Answer 49

corpus hemorrhagicum, corpus luteum.

Question 50

This is also known as a "yellow body and produces PROGESTERONE (pregnancy maintaining hormone) and some estrogen. ___ (large) luteal cells and __(small) luteal cells occupy space left by the ruptured follicle.

Answer 50

corpus luteum | granulosa luteal cells and theca luteal cells

Question 51

The corpus luteum regresses during ____ forming a connective tissue scar known as corpus___(white body)

Answer 51

diestrus, corpus albicans

Question 52

This is a follicle not selected to complete maturation , undergoes programmed destruction , this is the fate of many follicles

Answer 52

Atretic follicle

Question 53

During ovulation the oocyte___ the ovary leaving behind a structure know as the corpus ___________ that becomes the _____ ____ of theca and granulosa cells.

Answer 53

departs Corpus hemorrhagicum corpus luteum

Question 54

Spermatogenesis plan: spermatocytogenesis=spermatogenesis .This begins with a _____ (2n) mitosis; differentiate -->into a ____ spermatocyte (4n) meiosis I (crossover) --> 2____ spermatocytes(2n) meiosis II---> 4 ____(1n) DO NOT DIVIDE. but undergo spermiogenesis (metamorphosis) ---> 4 _____ (sperms, sperm cell)

Answer 54

``` spermatogonium primary spermatocyte secondary spermatocyte spermatids spermatozoa ```

Question 55

Functions of sertoli cells: - Activated by ___-___ hormone - secrete ____(anti mullerian hormone) during fetal development to inhibit uterus formation - secrete_____ to bind testosterone , increase concentration in seminiferous tubules and stimulate spermatogenesis. - provide___, protection, and possibly___ until spermatids become transformed into mature spermatozoa.

Answer 55

FSH follicle stimulating AMH ABP andogen bining protein support, nutrition

Question 56

Spermatogenesis :spermatogonia remain dormant until ___ then they proliferate by ___ division

Answer 56

puberty , mitotic

Question 57

Oogenesis: oogonia ____ their proliferation in the early embryonic stage

Answer 57

complete

Question 58

In spermatogenesis meiosis is completed within the

Answer 58

testis

Question 59

By birth all oognia entered meiosis I but their development is arrested in meiosis I until ____. Thus females are born with____ ____

Answer 59

puberty, primary oocytes

Question 60

Each spermatogonium gives rise to ____ spermatozoa

Answer 60

multiple

Question 61

One oocyte gives rise to___ ovum

Answer 61

one

Question 62

spermatids undergo_____ while ova do not.

Answer 62

metamorphosis

Question 63

spermatogenesis may continue throughout the whole life of the animal and in oogenesis meiosis is complete in the ____ (____ tube)

Answer 63

salpinx (fallopian tube)

Question 64

oogenesis stops after ovary is exhausted of germ cells this occurs between 10-12 years for ___ , 14-16 years for___ and 20-22 years for ___.

Answer 64

dogs cattle mares

Question 65

Fertilization -Sperm. 1. _____ -occurs in uterine environment (plasma membrane over acrosome is destabilized and breaks down together with acrosomal membrane) - sperm cells gain ability to fertilize the oocyte - Only ____ sperms can undergo acrosome reaction

Answer 65

capacitation, capacitated

Question 66

Fertilization -Sperm 2. ____ ____= release of ____ enzymes to digest way through the zona pellucida The sperm contacts the oocyte (most common in the fallopian tube.)

Answer 66

acrosomal reaction, acrosomal enzymes

Question 67

Fertilization- Sperm | 3. _____ of sperm plasma membrane with plasma membrane (vitelline membrane) of oocyte.

Answer 67

Fusion

Question 68

Fertilization - Ovum (oocyte II) | -cortex of oocyte below oolemma contains____ granules

Answer 68

cortical granules

Question 69

Fertilization- ovum Sperm contact with oocyte plasma membrane causes release of ___ from the cortical granules which modify the zona pellucida, The zona pellucida is then a ___ to other sperm penetration.

Answer 69

proteases | barrier

Question 70

Fertilization- Ovum - ___ wave causes oocyte to complete meiosis II -now 1N - nuclear material of sperm and ootid are called ___/___ ___

Answer 70

Ca++ | male /female pronuclei

Question 71

This is a union of male and female pronuclei . They merge restoring diploid (zygote) set of chromosomes and enter first ___ division 1N+1N=2N, this make a ___

Answer 71

Syngamy, mitotic zygote