2.7 (P2) Genetic Variation Flashcards
What does sexual reproduction lead to?
Variation
How many chromosomes are in a human body cell?
46
How many pairs are in a human body cell?
23
How many chromosomes in a gamete?
23
What are the female chromosomes?
XX
What are the male chromosomes?
XY
What are some characteristics controlled by?
1 gene = 2 alleles
What is an allele?
A version of a gene
What can the allele do?
Control the development of a characteristic
What is a dominant allele?
Always expressed in the phenotype even if another allele if present
What is a recessive allele?
Only expressed in the phenotype in the absence of a dominant allele
What is the equation used to describe characteristics?
Genotype + environment -> phenotype
What is your genotype?
Genes an organism possess
What is your phenotype?
Observable characteristics
What is heterozygous?
An organism containing cells with 2 different alleles for 1 gene
What is homozygous?
An organism containing cells with 2 of the same alleles
What is this…?
Aa
Heterozygous
What is this…?
AA
Homozygous dominent
What is this…?
aa
Homozygous recessive
What is polydactyly caused by?
A dominant allele
What is Polydactyly?
Having extra fingers or toes
What is cystic fibrosis caused by?
A recessive allele
What is cystic fibrosis?
A disorder of cell membranes causing thick, sticky mucus
What is the process of checking unborn babies for genetic diseases?
Embryonic screening
