Problem 4 - Campbell Biology

Question

Level 1: Knowledge/Comprehension A paleontologist has recovered a bit of tissue from the 400 -year- old preserved skin of an extinct dodo (a bird). To compare a specific region of the DNA from a sample with DNA from living birds, which of the following would be most useful for increasing the amount of dodo DNA available for testing? (A) SNP analysis (B) polymerase chain reaction (PCR) (C) electroporation (D) gel electrophoresis

Step-by-Step Solution

Answer

Polymerase Chain Reaction (PCR)

Step 1: Understand the question

The question asks for the most useful method to increase the amount of dodo DNA available for testing from a small tissue sample.

Step 1: Know your options

Familiarize yourself with the given options:(A) SNP analysis: Single Nucleotide Polymorphism analysis identifies variations in a single nucleotide.(B) Polymerase chain reaction (PCR): A technique used to amplify small segments of DNA.(C) Electroporation: A method used to introduce substances into a cell by applying an electric field.(D) Gel electrophoresis: A technique for separating DNA fragments based on their size.

Step 3: Eliminate unlikely options

SNP analysis, electroporation, and gel electrophoresis do not specifically increase the amount of DNA.

Step 2: Choose the best option

Polymerase Chain Reaction (PCR) is specifically designed to amplify DNA, making it the most suitable option.

Key Concepts

polymerase chain reaction (PCR)

Polymerase Chain Reaction (PCR) is a powerful laboratory technique used to amplify small segments of DNA. Its main purpose is to generate thousands to millions of copies of a particular DNA sequence.
This method is extremely precise and efficient, allowing scientists to analyze even tiny amounts of DNA.
Let's break down the PCR process:

• **Denaturation:** The double-stranded DNA is heated to separate it into two single strands.
• **Annealing:** Short DNA sequences called primers bind to the single-stranded DNA at specific locations.
• **Extension:** A special enzyme called Taq polymerase synthesizes a new strand of DNA by adding nucleotides to the primers.

This cycle repeats multiple times, exponentially increasing the DNA quantity. PCR is crucial in various fields, including genetics, forensics, and paleontology, as it enables the study of minute DNA samples from ancient specimens.

DNA analysis

DNA analysis involves examining DNA sequences to gain insights into genetic information. The process encompasses various techniques such as PCR, sequencing, and gel electrophoresis.
In the context of paleontology, DNA analysis can reveal information about extinct species, such as their evolutionary relationships, population dynamics, and genetic diversity.
Here are some key points:

• **Sequencing:** Determining the order of nucleotides in a DNA fragment.
• **Comparison:** Comparing DNA sequences from ancient samples with those of living organisms.
• **Mutation Identification:** Detecting genetic mutations that have occurred over time.

By analyzing DNA, scientists can reconstruct the genetic makeup of extinct species and understand their biology and evolution more comprehensively.

extinct species DNA

Extracting DNA from extinct species like the dodo bird is a complex process.
Due to DNA degradation over time, the recovered samples are often highly fragmented and contaminated.
Paleontologists and geneticists use advanced techniques, including PCR, to amplify and study these ancient DNA fragments.

• **Sample Recovery:** Obtaining a tissue sample, such as preserved skin, bone, or hair.
• **DNA Extraction:** Isolating DNA from the sample using chemical and mechanical methods.
• **Amplification:** Using PCR to amplify the small quantities of DNA available.

Studying ancient DNA helps scientists understand the genetic traits of extinct species and their evolutionary history, offering a window into the past.

genetic testing

Genetic testing involves examining DNA to identify changes or mutations in genes. It is widely used for diagnosing genetic disorders, ancestry tracing, and studying evolutionary biology.
In paleontology, genetic testing can shed light on the genetics of extinct species.
Here’s how genetic testing is applied:

• **Gene Identification:** Identifying specific genes and mutations in extinct species.
• **Comparison:** Comparing genetic data from extinct species with that of modern relatives.
• **Evolutionary Insights:** Understanding how species have evolved and adapted to their environments over time.

Through genetic testing, scientists can explore the biodiversity of past eras, providing valuable information for conservation and wildlife management efforts in the present.