BIOL 207 Lec 8

Genes and phenotypes

Where can you find information about a specific gene?

OMIN

What does lactase do?

Convert lactose in to glucose and galactose

What is spatial gene expression?

When the gene is “on” in only some cells. Important for multicellular organisms

What is temporal gene expression?

When a gene is only “on” in some stages of development

What is a heterozygote genotype?

A cell/organism with identical allele of a gene of interest. A/A or a/a

What is a homozygote genotype?

A cell/organism with different allele of a gene of interest. A/a

How would you write/type this genotype?

A/a

what is the difference between a gene and an allele?

A gene is a segment of DNA that determines a specific trait, while an allele is a specific variation of that gene, like different flavors of the same product.

What is usually the same about homologous chromosomes and what is different?

Homologous chromosomes usually have the same length, centromere position, band, and gene. Whats different are the alleles

What is phenotype?

the detectable outward manifestation of a specific genotype

True or false: In a heterozygote the recessive allele conceals the dominate allele

False. The dominate allele dominates the recessive allele

In a gene with a dominate allele for an expressed phenotype, can you deduce the second allele with only that information?

No, and some times it may not matter