Ch.16 - Genetic Crosses And Heredity Flashcards
What are gametes?
Gametes are haploid sex cells that are capable of fusion.
What is fertilisation?
Fertilisation is the union of 2 haploid gametes to form a diploid zygote.
What are alleles?
Alleles are alternative forms of the same gene.
What are dominant and recessive alleles?
Dominant alleles prevent recessive alleles from being expressed, while recessive alleles are prevented from being expressed by dominant alleles.
What is a genotype?
A genotype is the genetic make-up of an organism.
What is a phenotype?
A phenotype is the physical make-up of an organism. (They can be influenced by the environment).
What is progeny?
Progeny is offspring that are produced.
What are homozygous an heterozygous alleles?
Homozygous are a pair of identical alleles. Heterozygous are a pair of different alleles.
What is a Punnett square?
A Punnett square is a grid used to show the ratio of the genotypes of the progeny in a genetic cross.
What is incomplete dominance?
Incomplete dominance means that there is no dominant or recessive allele and the heterozygous condition produces an intermediate phenotype.
What is a pedigree?
A pedigree is a diagram showing the genetic history of a group of related individuals.
What are autosomes?
Autosomes are non-sex chromosomes.
State the law of segregation(Mendel’s first law).
Mendel’s first law states that inherited traits are controlled by 2 alleles. The alleles separate at gamete formation, with each gamete only having 1 allele.
State the law of independent assortment(Mendel’s second law).
Mendel’s second law states that either of a pair of alleles is equally likely to combine with either of another pair of alleles when gametes are being formed.
What is sex linkage?
Sex linkage is when a characteristic is controlled by a gene on a sex chromosome.
