The 4 Processes of Development: Cleavage – a series of cell divisions with out any cell growth or differentiation during the first 4 days after fertilization. It produces a ball of identical cells and all are about the same size as the original zygote. There is no growth because the ball of cells is traveling down the oviduct at this time. The only energy available to the ball of cells is stored in the cytoplasm because it is not yet attached to the mother yet. Morphogenesis – this is when the ball of identical cells begins to become several layers of different types of cells, making a pre-embryo with a tail and a head, then recognizable human features, and lastly a fetus with human form. Differentiation – individual cells take on specialized forms and functions. This makes the cells differentiate and the development of the organs and the organ system begin to take place due to morphogenesis. Growth – happens when the organism attaches to the mother, and thus is when it begins to grow in size.
Organs in the Urinary System:
- excrete metabolic wastes, especially urea
- maintain water and salt homeostasis
- helps regulate acid-base balance
- help regulate blood pressure
- control red blood cell production
- activate vitamin D
- transport urine to bladder
- stores urine until excretion
- transports urine to outside body
Define the following terms and give an example of each:
Co dominance – the relationship between 2 alleles when both are clearly visible and neither over power the other. This is known as a heterozygous genotype
EXAMPLE: In blood, A and B are co dominant. If a person has both A and B they have AB blood.
Complete Dominance – the dominant allele masks the recessive allele in a heterozygous genotype.
EXAMPLE: Eye color, if someone with brown eyes (BB, Bb) had a baby with someone with blue eyes (bb) there will be no middle between the blue eyes and brown if the pairing ends up being Bb. The baby will just have brown eye cause the B has complete dominance.