Cht 13 Meiosis Flashcards
Metaphase 1 and 2
1)
Homo chromos line up at metaphase plate 2X2 (tetrads-4chromo)
2)
Lines up 1x1 in 2 different cells
Prophase 1 and 2
1) synapsis= homo. Chromo. Pair up
Recombination= (crossing over) in synapsis homo chromo break and swap places (why bros and sis don’t look alike)
Chiasmata= where homo chromos touch (where recombination occurs)
2) both cells go thru same way ^
Anaphase 1 and 2
1) Homo chromosomes are pulled apart to opposite poles Sister chromatids are still connected 2) Sister chromatids pull apart
Telophase 1 and 2
1) parents cell has 6 chromos 2 daughter cells with 3 chromo =reduced the chromo numbers. 2) 4 haploid gametes Each with 3 chromos
Spermatogenesis
Formation of sperm via meiosis.
Oogenesis
Formation of ova (eggs) via meiosis
Zygote
The single cell resulting from fusion of the sperm (23) with the ovum(23)
Each have 23 chromos.
Zygote=46 chromos
Cleavage
The zygote will go thru mitosis to form multi-called embryo.
Stays same size but cells get smaller.
Steps of zygote to an embryo
Morula (solid ball of cells) > blastula (hollow ball) < blastoceol (hollow center).
Gastrulation (gas burp/fart) (movement of cells) > blastopore (mouth or anus).
Gastrula : endoderm (inside gut) and ectoderm (outside tissue).
Ectoderm Endoderm Mesoderm Blastopore Blastocoel
Skin Lines the guts Muscles Mouth/anus Body cavity