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Molecular Biology: A discipline concerned with studying biological phenomena in terms of the chemical and physical interactions of molecules.

Genetics of Organisms- Concept

JoVE 10557

Mendelian Genetics

Evolution is caused by changes in the genetic composition of populations. In the field of population genetics, scientists model this process as changes in the frequency of alleles at individual genetic loci. This simple representation of how evolution occurs dates to Gregor Mendel’s analysis of trait inheritance patterns in pea plants, first presented in 1865.…

 Lab Bio

Genetics of Speciation

JoVE 11126

Speciation is the evolutionary process resulting in the formation of new, distinct species—groups of reproductively isolated populations.

The genetics of speciation involves the different traits or isolating mechanisms preventing gene exchange, leading to reproductive isolation. Reproductive isolation can be due to reproductive barriers that have effects either before or after the formation of a zygote. Pre-zygotic mechanisms prevent fertilization from occurring, and post-zygotic mechanisms reduce the viability, or reproductive capacity, of the hybrid offspring. For example, pre-zygotic mechanisms act early in the life cycle of an organism, imposing the strongest impediment to gene flow, and preventing unfavorable mating combinations. Some mating combinations produce hybrid individuals. Natural selection can work against the production of hybrids with low fitness, thereby increasing reproductive isolation between two species. Post-zygotic reproductive barriers can be due to the intrinsic inviability of hybrids. Genetic complications resulting from aberrant ploidy levels, different chromosomal arrangements, or gene incompatibilities where the alleles do not function properly contribute to different genetic makeup and alternative developmental pathways in hybrids. These genetic alterations affect both plants and animals, leading to post-zygoti

 Core: Biology

An Overview of Genetic Analysis

JoVE 5540

An organism’s physical traits, or phenotype, are a product of its genotype, which is the combination of alleles (gene variants) inherited from its parents. To varying degrees, genes interact with each other and environmental factors to generate traits. The distribution of alleles and traits within a population is influenced by a number of factors, including natural…

 Genetics

Transformation of E. coli Cells Using an Adapted Calcium Chloride Procedure

JoVE 10515

Source: Natalia Martin1, Andrew J. Van Alst1, Rhiannon M. LeVeque1, and Victor J. DiRita1
1 Department of Microbiology and Molecular Genetics, Michigan State University


Bacteria have the ability to exchange genetic material (DeoxyriboNucleic Acid, DNA) in a process known as horizontal gene transfer. Incorporating exogenous DNA…

 Microbiology

Microscopy and Staining: Gram, Capsule, and Endospore Staining

JoVE 10513

Source: Rhiannon M. LeVeque1, Natalia Martin1, Andrew J. Van Alst1, and Victor J. DiRita1
1 Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, United States of America


Bacteria are diverse microorganisms found nearly everywhere on Earth. Many properties help distinguish them from…

 Microbiology

An Introduction to Saccharomyces cerevisiae

JoVE 5081

Saccharomyces cerevisiae (commonly known as baker’s yeast) is a single-celled eukaryote that is frequently used in scientific research. S. cerevisiae is an attractive model organism due to the fact that its genome has been sequenced, its genetics are easily manipulated, and it is very easy to maintain in the lab. Because many yeast proteins are similar in sequence and function…

 Biology I

Zebrafish Microinjection Techniques

JoVE 5130

One of the major advantages to working with zebrafish (Danio rerio) is that their genetics can be easily manipulated by microinjection of early stage embryos. Using this technique, solutions containing genetic material or knockdown constructs are delivered into the blastomeres: the embryonic cells sitting atop the yolk of the newly fertilized egg. Delivery into the cytoplasm is…

 Biology II

Genetic Screens

JoVE 5542

Genetic screens are critical tools for defining gene function and understanding gene interactions. Screens typically involve mutating genes and then assessing the affected organisms for phenotypes of interest. The process can be “forward”, where mutations are generated randomly to identify unknown genes responsible for the phenotypes, or it can be…

 Genetics
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