Chap 11 Flashcards
Allele
Alternative versions of the same gene that have different nucleotide sequences
Diploid
Having two copies of every chromosome. As in, humans have 23 pairs, making up 46
Homologous Chromosomes
A pair of chromosomes that both contain the same genes. In a diploid cell, one chromosome in the pair is inherited from the mother, the other from the father.
Phenotype
The visible or measurable features of an individual
Genotype
The particular genetic makeup of an individual
Gametes
Specialized reproductive cells that carry one copy of each chromosome (that is, they are haploid). Sperm are male gametes; eggs are female gametes.
Haploid
Having only one copy of every chromosome
Meiosis
A type of cell division that generates genetically unique haploid gametes
Zygote
A diploid cell that is capable of developing into an adult organism. The (blank) is formed when a haploid egg is fertilized by a haploid sperm
Embryo
An early stage of development reached when a zygote undergoes cell division to form a multi-cellular structure
Recombination
An event in meiosis during which maternal and paternal chromosomes pair and physically exchange DNA segments
Independent Assortment
The principle that alleles of different genes are distributed independently of one another during meiosis
Recessive Allele
An allele that reveals itself only if a masking dominant allele is not present
Dominant Allele
An allele that can mask the presence of a recessive allele
Heterozygous
Having two different alleles for a given gene
Homosygous
Having two identical alleles for a given gene
Punnet Square
A diagram used to determine probabilities of offspring having particular genotypes, given the genotype of the parents
Carrier
An individual who is heterozygous for a recessive allele and can therefore pass it on to offspring without showing any of its effects
