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
What molecules are chromosomes made up of?
DNA
What phrase describes DNA?
Double helix
What does a gene code for?
A particular combination of amino acids with make a specific protein
