Terms in this set (20)
a collection of DNA and proteins in a thread-like structure carrying genetic information in the form of genes
a sequence of DNA on a chromosome controlling a specific characteristic.
different forms of the same gene, occupying the same place on a chromosome, and affecting the same characteristics but in different ways.
a nucleus containing a single set of unpaired chromosomes. Gamete cells are haploid. The haploid number of chromosomes is written as n
a nucleus with two sets of paired chromosomes, one set comes from the female parent and the other from the male. The diploid number of chromosomes is written as 2n
all the alleles possessed by an organism
all the characteristics that an organism has as a result of its genotype.
having two identical alleles of a gene
having two different alleles of a gene
will always be expressed if present, only need one copy eg Aa
need to have 2 copies of recessive allele eg aa
chromosome pairs, one from each parent that are similar in length, gene position and centromere location. The genes may contain different alleles.
a spontaneous change in the genetic material of a cell.
sperm or egg
cell division in body cells to produce identical cells with identical chromosome
formation of gametes with half number of chromosomes produces VARIATION
the ratio of the offspring's phenotypes eg 3 brown to 1 blond hair
a diploid cell resulting from the fusion of two haploid gametes; a fertilized ovum.
When individuals breed "true" for a trait
A cross between individuals that involves one pair of contrasting traits