Syntenic Blocks Are Sections of Chromosomes That Have Remained Largely

question 16

Multiple Choice

Syntenic blocks are sections of chromosomes that have remained largely intact during evolution. For example, human chromosome 4 corresponds to syntenic blocks on mouse chromosomes 3, 5, and 8. Which of the following statements about synteny are true? Please select all that apply.

• A) No crossovers occur in syntenic blocks
• B) The ancestor of humans and mouse probably had similar syntenic blocks to those currently seen in mouse and human
• C) X chromosomes are largely syntenic between placental mammals
• D) The ancestor of humans and mouse had syntenic blocks as in human and these were rearranged to make different chromosomes in mouse

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Definitions:

Complex Eye

A type of eye structure found in some animals, consisting of numerous individual light-sensitive units, allowing for the perception of detailed images.

Antagonistic Pleiotropy

The condition that occurs when a mutation with beneficial effects for one trait also causes detrimental effects on other traits.

Net Fitness Effect

The overall impact of an allele or trait on an organism's reproductive success and survival across its lifespan.

Allele

One of any number of alternative forms of the DNA sequence of the same locus.