ch03 lecture ppt - barksdale science...7kh )hpdoh 5hsurgxfwlyh 6\vwhp 2rf\whv pdwxuh lq wkh rydulhv...
TRANSCRIPT
![Page 1: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/1.jpg)
Human GeneticsConcepts and Applications
Tenth EditionRICKI LEWIS
Copyright ©The McGraw-Hill Companies, Inc. Permission required for reproduction or display
PowerPoint® Lecture Outlines Prepared by Johnny El-Rady, University of South Florida
Meiosis and Development
![Page 2: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/2.jpg)
2
Stages of the Human Life CycleGenes orchestrate our physiology after
conception through adulthoodDevelopment is the process of forming an
adult from a single-celled embryoIn humans, new individuals form from the
union of sex cells or gametes- Sperm from the male and oocyte from the female form a zygote
![Page 3: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/3.jpg)
3
The Male Reproductive SystemSperm cells are made in the seminiferous
tubules of the testesThe prostate gland, seminal vesicles, and
bulbourethral glands add secretions to form the seminal fluid
Sperm mature and are stored in the epididymis
They leave through the ductus deferens and then the urethra
![Page 4: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/4.jpg)
4
bladderurethra
testis
vas deferens
epididymisbulbourethralgland
seminal vesicle
prostate
Figure 3.1
The Male Reproductive System
Figure 3.1
![Page 5: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/5.jpg)
5
The Female Reproductive SystemOocytes mature in the ovariesEach month, an ovary releases an oocyte
into the uterine tube- If the oocyte is fertilized, it continues to the uterus where it divides and develops- If it is not fertilized, the body expels it, along with the uterine-lining via the menstrual flow
Hormones control the cycle of oocyte development
![Page 6: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/6.jpg)
6Figure 3.2
The Female Reproductive System
Figure 3.2
![Page 7: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/7.jpg)
7
MeiosisThe cell division that produces gametes with
half the number of chromosomesOccurs in special cells called germline cellsMaintains the chromosome number of a
species over generationsEnsures genetic variability via the processes
of independent assortment and crossing over of chromosomes
![Page 8: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/8.jpg)
8
Meiosis consists of two divisions - Meiosis I = The reduction division
- Reduces the number of chromosomes from 46 to 23
- Meiosis II = The equational division- Produces four cells from the two produced in Meiosis I
Note = Each division contains a prophase, a metaphase, an anaphase and a telophase
![Page 9: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/9.jpg)
9
Meiosis
Figure 3.3
![Page 10: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/10.jpg)
10
Meiosis IFigure 3.4
![Page 11: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/11.jpg)
11Figure 2.3
Prophase IHomologs pair-up
and undergo crossing over
Chromosomes condense
Spindle formsNuclear envelope
breaks down
![Page 12: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/12.jpg)
12Figure 2.3
Crossing-over
Figure 3.5
![Page 13: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/13.jpg)
13Figure 2.3
Metaphase IHomologous pairs align along
the equator of the cell
The random alignment pattern determines the combination of maternal and paternal chromosomes in the gametes
![Page 14: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/14.jpg)
14Figure 2.3
Independent Assortment
Figure 3.6
![Page 15: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/15.jpg)
15Figure 2.3
Anaphase IHomologs separate
and move to opposite poles of the cell
Sister chromatids remain attached at their centromeres
![Page 16: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/16.jpg)
16Figure 2.3
Telophase INuclear envelope
reforms
Spindle disappears
Cytokinesis divides cell into two
![Page 17: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/17.jpg)
17Figure 2.3
InterkinesisA short interphase between the two meiotic
divisionsChromosomes unfold into very thin threadsProteins are manufacturedHowever, DNA is NOT replicated a second
time
![Page 18: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/18.jpg)
18
Meiosis IIFigure 3.4
![Page 19: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/19.jpg)
19Figure 2.3
Prophase IIChromosomes are again
condensed and visibleSpindle formsNuclear envelope
fragments
Metaphase IIChromosomes align
along the equator of the cell
![Page 20: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/20.jpg)
20Figure 2.3
Anaphase IICentromeres divideSister chromatids
separate to opposite cell poles
Telophase IINuclear envelope
reforms Chromosomes uncoilSpindle disappears
![Page 21: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/21.jpg)
21Figure 2.3
Results of MeiosisFour haploid cells
containing a single copy of the genome
Each cell is unique –carries a new assortment of genes and chromosomes
![Page 22: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/22.jpg)
22Table 3.1
Comparison of Mitosis and Meiosis
![Page 23: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/23.jpg)
23Figure 2.3
SpermatogenesisA diploid spermatogonium divides by mitosis to
produce a stem cell and another cell that specializes into a primary spermatocyte
In meiosis I, the primary spermatocyte produces two haploid secondary spermatocytes
In meiosis II, each secondary spermatocyte produces two haploid spermatids
Spermatids then mature into a tad-pole shapedspermatozoa
![Page 24: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/24.jpg)
24Figure 3.7
Spermatogenesis
Figure 3.7
![Page 25: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/25.jpg)
25Figure 3.7
Spermatogenesis
Figure 3.8
![Page 26: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/26.jpg)
26
Spermatogenesis
Figure 3.9
![Page 27: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/27.jpg)
27Figure 2.3
OogenesisA diploid oogonium divides by mitosis to produce a
stem cell and another cell that specializes into a primary oocyte
In meiosis I, the primary oocyte divides unequally forming a small polar body and a large secondary oocyte
In meiosis II, the secondary oocyte divides to form another polar body and a mature haploid ovum
Figure 3.10
![Page 28: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/28.jpg)
28Figure 2.3
OogenesisUnlike spermatogenesis, oogenesis is a
discontinuous processA female begins meiosis when she is a fetus
- Oocytes arrest at prophase I until puberty- After puberty, meiosis I continues in one or several oocytes each month but halts again at metaphase II- Meiosis is only completed if the ovum is fertilized
![Page 29: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/29.jpg)
29Figure 3.7
Oogenesis
Figure 3.11
![Page 30: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/30.jpg)
30Figure 3.7
Oogenesis
Figure 3.12
![Page 31: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/31.jpg)
31Figure 2.3
FertilizationUnion of sperm and ovumIn the female, sperm are capacitated and
drawn to the secondary oocyteAcrosomal enzymes aid sperm penetrationChemical and electrical changes in the
oocyte surface block entry of more spermThe two sets of chromosomes fuse into one
nucleus, forming the zygote
![Page 32: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/32.jpg)
32Figure 2.3
Fertilization
Figure 3.13
![Page 33: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/33.jpg)
33Figure 2.3
CleavageA period of frequent mitotic divisions
- Resulting cells are called blastomeresDeveloping embryo becomes a solid ball of
16+ cells called a morulaThe ball of cells hollows out to form a
blastocyst
![Page 34: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/34.jpg)
34Figure 2.3
BlastocystConsists of two main parts
- Inner cell mass (ICM), which develops into the embryo- Trophoblast, which develops into the placenta
Implantation in the uterus occurs around day 7Certain blastocyst cells secrete human chorionic
gonadotropin (hCG)- A sign of pregnancy
![Page 35: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/35.jpg)
35Figure 2.3
From Ovulation to Implantation
Figure 3.14
![Page 36: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/36.jpg)
36Figure 2.3
GastrulationThe primary germ layers form in the second
week after fertilization- Ectoderm (outermost layer)- Mesoderm (middle layer)- Endoderm (innermost layer)
This three-layered structure is the gastrulaCells in each germ layer begin to form
specific organs
![Page 37: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/37.jpg)
37Figure 2.3
Supportive StructuresStructures that support and protect the
embryo include:- Chorionic villi - Yolk sac- Allantois- Umbilical cord- Amniotic sac
By 10 weeks the placenta is fully formed
![Page 38: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/38.jpg)
38Figure 3.15
The Primordial Embryo
Figure 3.15
![Page 39: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/39.jpg)
39
Table 3.2
Stages of Prenatal Development
![Page 40: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/40.jpg)
40Figure 2.3
Multiple BirthsDizygotic twins (Fraternal)
- Arise from two fertilized ova- Same genetic relationship as any two siblings
Monozygotic twins (Identical)- Arise from a single fertilized ovum- Embryo splits early during development- Twins may share supportive structures
![Page 41: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/41.jpg)
41Figure 3.16
Figure 3.16
![Page 42: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/42.jpg)
42Figure 3.17
![Page 43: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/43.jpg)
43Figure 2.3
The Embryo DevelopsOrganogenesis is the transformation of the
simple three germ layers into distinct organsDuring week 3, a band called the primitive streak
appears along the back of the embryoThis is followed rapidly by the notochord, neural
tube, heart, central nervous system, limbs, digits, and other organ rudiments
By week 8, all the organs that will be present in the newborn have begun to develop- The prenatal human is now called a fetus
![Page 44: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/44.jpg)
44Figure 3.18
The Embryo Develops
Figure 3.18
![Page 45: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/45.jpg)
45Figure 2.3
The Fetus GrowsDuring the fetal period, structures grow,
specialize and begin to interactBone replaces cartilage in the skeletonBody growth catches up with the headSex organs become more distinctIn the final trimester, the fetus moves and
grows rapidly, and fat fills out the skinThe digestive and respiratory systems
mature last
![Page 46: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/46.jpg)
46Figure 2.3
Birth DefectsThe time when a particular structure is
sensitive to damage is called its critical period
Birth defects can result from a faulty gene or environmental insult
Most birth defects develop during the embryonic period- These are more severe than those that arise during the fetal period
![Page 47: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/47.jpg)
47Figure 3.20
Critical Periods of Development
Figure 3.19
![Page 48: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/48.jpg)
48Figure 2.3
TeratogensChemical or other agents that cause birth
defectsExamples
- Thalidomide- Cocaine- Cigarettes- Alcohol- Some nutrients- Some viruses
![Page 49: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/49.jpg)
49Figure 3.21
Fetal Alcohol Syndrome
Figure 3.20
![Page 50: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/50.jpg)
50Figure 2.3
AgingGenes may impact health throughout lifeSingle-gene disorders that strike in
childhood tend to be recessiveAdult-onset single-gene traits are often
dominant Interaction between genes and
environmental factors - Example: Malnutrition before birth
![Page 51: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/51.jpg)
51Figure 3.21
![Page 52: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/52.jpg)
52Figure 2.3
AgingGenes control aging both passively and
activelyA few single-gene disorders can speed
the signs of agingSegmented progeroid
syndromes- Hutchinson-Guilford syndrome
Figure 3.22
![Page 53: ch03 lecture ppt - BARKSDALE SCIENCE...7KH )HPDOH 5HSURGXFWLYH 6\VWHP 2RF\WHV PDWXUH LQ WKH RYDULHV (DFK PRQWK DQ RYDU\ UHOHDVHV DQ RRF\WH LQWR WKH XWHULQH WXEH ,I WKH RRF\WH LV IHUWLOL]HG](https://reader034.vdocuments.mx/reader034/viewer/2022051809/6012fc6fe17f9d7165061c88/html5/thumbnails/53.jpg)
53Figure 2.3
Is Longevity Inherited?Aging reflects genetic activity plus a
lifetime of environmental influencesHuman chromosome 4 houses longevity
genes-Genome-wide screens of 100-year olds are identifying others
Adoption studies compare the effects of genes vs. the environment on aging