Freezing Conditions and Enzymatic Decay Quiz

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Which ancient species have full genome sequences available for de-extinction?

Sabre-tooth tigers
Woolly mammoths (correct)
Giant sloths
Tasmanian tigers

What is the main challenge in recovering DNA from ancient remains preserved in hot and wet environments?

Lack of funding
Lack of available technology
DNA degradation (correct)
Difficulty in obtaining samples

Why can't ancient genomes be assembled de novo?

The taxonomic biases affect the sequencing process
The DNA fragments are too fragmented
The recovered DNA fragments are too short (correct)
The sequencing technology is not available

Which of the following is not one of the main approaches to achieve de-extinction?

Paleogenomics (C) Signup and view all the answers

What is the scientiﬁc process known as SCNT?

Somatic cell nuclear transfer (B) Signup and view all the answers

Why is cloning of long-dead organisms not likely to be feasible?

Biological remains degrade post-mortem (A) Signup and view all the answers

Why should we consider de-extinction as a means to create ecological proxies for extinct species?

Because even species with cloned nuclear genomes will not be exact copies of the extinct species (A) Signup and view all the answers

Which technique is used for cloning and creating an exact genetic copy of a living organism?

Somatic cell nuclear transfer (A) Signup and view all the answers

What is the main advantage of cloning for de-extinction purposes?

The resulting organism will be identical to the extinct donor at all levels (C) Signup and view all the answers

What is the success rate of potential clones developing into live offspring on average?

<5% (D) Signup and view all the answers

What is the main challenge of using cloning for de-extinction purposes?

Most extinct species do not have available living cells for cloning (C) Signup and view all the answers

Which of the following is NOT one of the three main pathways being considered for de-extinction?

Selective breeding (B) Signup and view all the answers

What is the goal of back-breeding in the context of de-extinction?

To concentrate ancestral traits that persist within a population into a single individual using selective breeding (A) Signup and view all the answers

What is the state of the art in genetic engineering for de-extinction?

It is still in the early stages of development and has not yet been successful in resurrecting an extinct species (B) Signup and view all the answers

Which of the following is a reason why larger animals may experience more enzymatic decay during freezing?

They freeze more slowly than smaller animals (C) Signup and view all the answers

What is the oldest frozen specimen from which healthy clones have been generated?

A 16-year-old mouse (D) Signup and view all the answers

What is the most likely route to de-extinction according to the author?

Reconstructing genome sequences and using genome engineering (A) Signup and view all the answers

Why did early ancient DNA research concentrate on animals that lived and died in arctic regions?

Because DNA decays more slowly in cold environments (C) Signup and view all the answers

Which of the following is a limitation of back-breeding as an approach to de-extinction?

Back-breeding requires that the target ancestral traits persist within a living species (D) Signup and view all the answers

What is back-breeding?

The use of selective breeding to resurrect specific ancestral traits within populations of living organisms (D) Signup and view all the answers

What is the end-goal of de-extinction projects according to the text?

To restore critical interactions among species that are no longer alive (C) Signup and view all the answers

What are the potential risks of back-breeding as an approach to de-extinction?

Back-breeding may reduce the population's overall fitness by increasing inbreeding (D) Signup and view all the answers

Which species was successfully cloned using SCNT from frozen fibroblast cells?

Bucardo (A) Signup and view all the answers

What did the cloning of a mouflon from a non-viable cell harvested from an animal that had been found dead in a field suggest?

Freezing and desiccation can promote the long-term preservation of biomolecules within organismal remains (A) Signup and view all the answers

What was the main challenge faced in the studies that used frozen (archived) cells for SCNT?

The eﬃciency of embryo generation declined with the amount of time that the cells had been frozen (A) Signup and view all the answers

How were the cloned mouse embryos created from freeze-dried cells, cells that were frozen for nearly a year, and cells taken from mice whose entire bodies had been frozen for up to 16 years?

Entire cells were injected directly into enucleated eggs (B) Signup and view all the answers

Which extinct species was the first targeted for de-extinction?

Aurochs (D) Signup and view all the answers

What is the advantage of present-day backbreeding efforts for aurochs?

All of the above (D) Signup and view all the answers

What is the difference between aurochs and Heck cattle?

Heck cattle have a more primitive appearance than aurochs (A) Signup and view all the answers

What is the process for de-extinction using genome editing?

Harvest cells from a closely related living species, change the genome sequence to resemble the extinct species, implant embryo into a surrogate host (B) Signup and view all the answers