Praktikum Genetika-Simulasi Berangkai dan Pindah Silang

Summary

This video demonstrates a genetics practical focusing on crossover and recombination in chromosomes. Group 7 members guide viewers through the process of creating chromatid models using plasticine and performing crossover simulations to explore genetic inheritance. The practical illustrates how alleles exchange during crossover events and how this results in genetic variation. By simulating different crossover scenarios, the video highlights the role of recombination in shaping genetic diversity, providing a hands-on understanding of genetic processes in inheritance.

Takeaways

• 😀 The practical demonstration focuses on simulating genetic processes like crossing over and chromosomal recombination.
• 😀 Students use colored plastine to represent chromosomes in the experiment.
• 😀 The experiment involves creating chromosomal structures by rolling plastine into thread-like shapes.
• 😀 The centromere locations are marked using wax of the same color as the chromosomal pair.
• 😀 The first stage of the crossover involves a single crossover between two alleles, exchanging genetic material.
• 😀 After the crossover, the number of centromeres doubles from two to four as a result of the genetic exchange.
• 😀 The alleles change after the crossover, leading to new combinations, such as from A-B to A-b or a-B to a-b.
• 😀 The experiment progresses through multiple stages of crossover, each with different allele combinations.
• 😀 The second stage demonstrates a double crossover, further altering allele combinations and chromosomal configurations.
• 😀 The video concludes with a summary of the final allele combinations after all crossovers have been completed, emphasizing the genetic variation that occurs.

Q & A

What is the primary objective of the practical work described in the video?

The primary objective of the practical work is to study the process of crossing-over and its consequences in genetics.

What tools and materials were used in the experiment?

The tools included a pen or pencil, an eraser, a ruler, and a camera. The materials used were colored plastine (red, green, yellow, and blue), tissues, and A4 HVS paper.

What is the first step in the experiment after preparing the plastine?

The first step is to create two chromatids with the same color and two chromatids with different colors, followed by forming them into chromatin threads.

How is the centromere marked during the experiment?

The centromere is marked by using wax of the same color as the pair of chromatids.

What is the concept of 'crossing-over' as demonstrated in the experiment?

Crossing-over refers to the exchange of genetic material between chromatids during the simulation, leading to genetic variation in the resulting alleles.

How do the alleles change after the crossing-over process?

After crossing-over, the alleles can change, such as from 'A big B big' to 'A big B small' or other combinations, reflecting the genetic recombination that occurs during the process.

What happens to the number of centromeres after crossing-over?

Initially, there are two centromeres, but after crossing-over, the number of centromeres increases to four.

What is the result of the second crossing-over simulation with fragments BC?

In the second crossing-over simulation, the alleles from the different fragments are exchanged, leading to new allele combinations like 'A big B small' and 'C small' or other variants depending on the crossover patterns.

How are the crossing-over fragments combined after the crossovers?

After the crossing-over, the segments of the chromatids are cut and rejoined or combined to form new chromatids with different allele combinations.

What is the final goal of the practical experiment shown in the video?

The final goal is to observe and understand how crossing-over affects allele combinations and genetic variation, which is essential in genetic studies and inheritance patterns.