Who First Noticed That for Cepheid Variable Stars, There Was

question 43

Multiple Choice

Who first noticed that for Cepheid variable stars, there was a direct relation between the luminosity and the period of the variation in their brightness?

• A) Henrietta Leavitt
• B) Edwin Hubble
• C) John Glenn
• D) Carl Sagan
• E) Annie Cannon

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Definitions:

Horizontal Gene Transfer

Horizontal gene transfer is the transfer of genetic material — other than from parent to offspring — to another organism, sometimes a distantly related one, without reproduction. Once this material is added to the recipient’s genome, it can be inherited by descent.

Genome Size

The total amount of DNA contained within one copy of a single complete set of chromosomes of an organism.

Genetic Hitchhiking

The process by which an allele rises in frequency within a population because it is linked to a beneficial allele under selection.

Tree Topologies

The arrangement and structure of branches in a phylogenetic tree, representing evolutionary relationships among various species or genes.