Powerpoint chapter 7 Flashcards
Specialized form of cell division in gonads to produce gametes
Meiosis
Reduces number of chromosomes in each cell by one half
Meiosis
Chromosomes come in ________ pairs.
Homologous
_______ gets one of each pair.
Gamete
a photograph of chromosomes arranged in pairs
Karyotype
Human somatic cells have ____ pairs of ______.
22
autosomes
Human somatic cells have ___ pair of ___ _________.
1
Sex chromosomes
Specialized sex cells (egg, sperm)
Gametes
Produced by meiosis in the gonads (sex organs)
Gametes
_______ _____, with one set of 23 chromosomes in humans
Haploid cells
Fused gametes (during fertilization) form a ____ _____.
diploid zygote
Egg cell has 23 chromosomes (_________)
Unpaired
Sperm cell has 23 chromosomes (_______)
Unpaired
DNA is duplicated during interphase.
Meiosis
Meiosis takes place in how many stages?
2
Separating out the homologous Paris into two separate cells.
Meiosis 1
Separating out the sister chromatids in each cell to produce four haploid cells.
Meiosis 2
Exchange of genetic information between homologous chromosomes
Crossing over
Occurs during prophase 1 of meiosis 1
Crossing over
Results in new types of gametes
Crossing over
Typically cross over together
Linked genes
The random arrangement and separation of different pairs of chromosomes during meiosis 1
Random alignment
Results in genetically distinct gametes
Random Alignment
Segments of DNA that code for proteins
Genes
Single, circular chromosomes
Prokaryotes
Linear chromosomes
Eukaryotes
Human cells have ___ chromosomes
46
About ________ different combinations of chromosomes are possible.
8 million
produces more diversity
Random fertilization
8 million x 8 million =
64 trillion possibilities
