anatomy test chapter 3

23

sperm and egg

gametes, only have 23

diploid

Haploid

• type of sex cell
• starts with diploid parent cell and produces haploid daughter cell

mitosis dividing if cells resulting cells are identical

meiosis the dividing of sex cells resulting cells are not identical

• occurs in meiosis
• allows an exchange in genetic material between paired chromosomes
• results in gametes that have genes from both parents

• 1 start with one diploid cell
• 2 at the end of meiosis I, we have 2 daughter diploid cells
• 3 end od Meiosis II each of the above diploid cells has produced 2 haploid cell
• (Meiosis starts with 1 Diploid Cell and produces 4 Haploid cells)

Prophase I

parent cells that produce haploid sperm through the process of meiosis

cells that have under gone meiosis to produce haploid cells with (23 chromosomes)

upper 1/3 of uterine tube

zygote

• Pre-Embryonic
• Embryonic
• Fetal Period

• first 2 weeks
• single egg (zygote)
• cleavage & compaction & morula 
• becomes a multicellular structure (blastocyst)
• ends when blastocyst implants into the uterine lining

• weeks 3 to 8
• Rudimentary versions of major organ system appear
• Referred to as a Embryo

• remaining 30 weeks
• baby grows and prepares for birth

after the zygote is formed it goes thru a series of mitotic divisions

although the number of cells increase the total size of the organism remains constant

Morula

a fluid filled blastocyst will develop in the center of the morula

• embryonic membranes are formed
• Yolk Sac
• amnion
• Chorion

chorion

early blood cell and vessel formation

encloses the embryo in fluid filled sac that prevents desiccation