Unit 3-Molecular Genetics Lesson 3 1.0 Flashcards
What is a key characteristic of prokaryotic DNA organization?
Prokaryotic DNA consists of one circular chromosome.
How is prokaryotic DNA typically structured?
Prokaryotic DNA is less tightly bound but still coiled (supercoiling).
What allows prokaryotic DNA to be easily accessed?
Prokaryotic DNA can be easily accessed by enzymes and other molecules involved in replication.
What are smaller circular DNA pieces in prokaryotes called?
These smaller circular DNA pieces are known as plasmids.
What occurs during conjugation in prokaryotic cells?
During conjugation, plasmids can exit the cell and enter another cell.
What is one major problem associated with eukaryotic DNA replication?
The last Okazaki fragment on the lagging strand cannot be completed due to the absence of adjacent DNA to the 5’ end.
What happens to the RNA primer on the final Okazaki fragment in eukaryotic DNA?
The RNA primer is removed and not replaced, leading to a shorter final DNA strand.
What are telomeres?
Telomeres are non-coding regions found at the ends of eukaryotic chromosomes that help prevent gene loss during replication.
What happens to telomeres during DNA replication?
Part of the telomeres are lost with every DNA replication instead of coding regions.
What functions do telomeres serve?
Telomeres prevent chromosome ends from fusing, protect against DNA degradation, assist in DNA repair, and may determine the cell division limit.
What is the Hayflick limit?
The Hayflick limit is the total number of times a cell can divide, marking the biological clock of the cell.
What occurs when a cell reaches its Hayflick limit?
It enters a period of decline in function known as senescence, marking the beginning of aging.
How do cancer cells differ from healthy cells regarding telomeres?
Cancer cells produce telomerase, allowing them to maintain and extend their telomeres, enabling indefinite division.
What role do telomeres play in aging?
Telomeres shorten with each replication, potentially leading to loss of crucial coding regions and decreased cell function, contributing to aging.
Provide an example of a research subject related to telomeres and aging.
The cloning of Dolly the sheep is a notable example in the study of telomeres and aging.
