describes the changes in an
organism from its earliest
beginnings through maturity.
Development
SPERMATOGENESIS
- What are parts of spermatogenesis?
- How many sperm being formed?
- primary spermatocyte, secondary spermatocyte, spermatid, sperm
- 1,500 per second, up to 800 billion sperm
OOGENESIS
- What are parts of oogenesis?
- How many egg cells being formed?
- primary oocyte, secondary oocyte, polar body, ovum
- 1
union of Sperm and egg cell
Fertilization
What are the parts of human egg (ovum)?
- Nucleus
- Cytoplasm
- Cortical granule
(layers)
- Corona radiata (follicular cells)
- Zona pellucida (jelly coat)
- Vitelline layer
What are the parts of human sperm (spermatozoa)?
- Acrosome
- Nucleus
- Centriole
- Midpiece
- Mitochondria
- Tail/Flagellum
- Axoneme
Steps in Fertilization
1. Sperm makes its way through _____.
2. _____ enzymes digest a portion of _____.
3. Sperm binds to and fuses with _____.
4. _____ enters cytoplasm of egg.
5. _____ release enzymes; zona pellucida becomes _____.
6. Sperm and egg pronuclei are enclosed in a _____.
- corona radiata
- Acrosomal, zona pellucida
- egg plasma membrane
- Sperm nucleus
- Cortical granules, fertilization membrane
- nuclear envelope
Once fertilization is complete, the zygotes of many animal species undergo a succession of rapid cell divisions that characterize the _____ stage of early development.
Cleavage
After fertilization happens, _____ (early cell division by mitosis) of the zygote begins.
cleavage
Cleavage results in a _____, a hollow ball of cells that contains an inner cellar mass, which will form the embryo
blastula (the mammalian version is called a blastocyst)
Cleavage (time interval)
0hr - 1
30hr - 2
60hr - 4
ndays - blastomere
6 days - Blastula
the process during embryonic development that changes the embryo from a blastula with a single layer of cells to a _____ containing multiple layers of cells.
Gastrulation
What is the difference between the Blastula and Gastrula?
- blastula - single layer of cells
- gastrula - multiple layers of cells.
What are the parts of gastrula?
- Ectoderm (forms exoskeleton)
- Mesoderm (develops into organs)
- Endoderm (inner lining of organs)
The cells interact with one another and rearrange themselves to produce tissues and organs.
Organogenesis
Embryonic development
9w -
12w -
16w -
20w -
24w -
28w -
32w -
36w-
40w -
9w - fetal stage
12w - sex organs
16w - fingers and toes
20w - hearing
24w - lungs
28w - brain
32w - bones
36w- muscles
40w - full-term
What are the steps in development?
- Gamete formation (sperm & egg form)
- Fertilization (sperm & egg fuse)
- Cleavage (zygote subdivides, blastomeres)
- Gastrulation (germ layer form)
- Organogenesis (body organs form, cells interact)
- Growth (organs increase in size, adult body form attained)
