Meiosis key words Flashcards
The type of nuclear division in which the number of chromosomes is halved
Meiosis
Reproductive (sex) cell that fuses with another gamete during fertilisation
Gamete
Cell or nucleus containing pairs of homologous chromosomes (two sets of chromosomes)
Diploid
Cell or nucleus containing single, unpaired chromosomes (a single copy of each chromosome)
Haploid
A pair of chromosomes, one maternal and one paternal, that have the same gene loci and therefore determine the same features. They are not necessarily identical as may have different alleles. They are capable of pairing during meiosis
Homologous chromosomes
The process whereby a chromatid breaks during meiosis and rejoins to the chromatid of its homologous chromosome so that their alleles are exchanged
Crossing over
A point at which paired chromosomes remian in contact during the first metaphase of meiosis and at which crossing over and exhange of genetic material occur between the strands
Chiasmata
The rearrangement of genetic material, especially by crossing over in chromosomes
Recombination
The alleles of two (or more) different genes get sorted into gametes independently of one another. The allele a gamete recieves for one gene does not influence the allele revieved for another gene. This is because homologous chromosomes line up in random orientations at the middle of the cell at metaphase as they prepare to separate, meaning that the same parent cell can produce different combinations of chromosomes in the daughter cells
Independent assortment
During the formation of gametes, each gamete recieves just one gene copy, which is selected randomly. Each pair of alleles segregates independently of the other pairs and all possible combinations of alleles can occur in the resulting gametes
Independent segregation
Differences between individuals. It can be interspecific (between different species) or intraspecific variation (between individuals of the same species)
Variation
