Related Experiment Video

Updated: Aug 9, 2026

Observation and Quantification of Mating Behavior in the Pinewood Nematode, Bursaphelenchus xylophilus
09:55

Observation and Quantification of Mating Behavior in the Pinewood Nematode, Bursaphelenchus xylophilus

Published on: December 25, 2016

Assortative mating between chromosome forms of the mole rat, Spalax ehrenbergi

E Nevo, G Heth

    Experientia
    |December 15, 1976
    PubMed

    More Related Videos

    Manipulation of Ploidy in Caenorhabditis elegans07:54

    Manipulation of Ploidy in Caenorhabditis elegans

    Published on: March 15, 2018

    Frequency and Distribution of Crossovers in Caenorhabditis elegans Meiosis by SNP Genotyping using Real-time PCR06:18

    Frequency and Distribution of Crossovers in Caenorhabditis elegans Meiosis by SNP Genotyping using Real-time PCR

    Published on: July 11, 2025

    Related Concept Videos

    Mate Choice01:20

    Mate Choice

    Mate choice—the decision about whom to mate with—is a type of natural selection, since animals must reproduce to pass down their genes. Mate choice is also called intersexual selection because the behavior occurs between the sexes.
    Frequency-dependent Selection01:21

    Frequency-dependent Selection

    When the fitness of a trait is influenced by how common it is (i.e., its frequency) relative to different traits within a population, this is referred to as frequency-dependent selection. Frequency-dependent selection may occur between species or within a single species. This type of selection can either be positive—with more common phenotypes having higher fitness—or negative, with rarer phenotypes conferring increased fitness.Positive Frequency-Dependent SelectionIn positive...
    Hardy-Weinberg Principle01:49

    Hardy-Weinberg Principle

    Diploid organisms have two alleles of each gene, one from each parent, in their somatic cells. Therefore, each individual contributes two alleles to the gene pool of the population. The gene pool of a population is the sum of every allele of all genes within that population and has some degree of variation. Genetic variation is typically expressed as a relative frequency, which is the percentage of the total population that has a given allele, genotype or phenotype.In the early 20th century,...
    Chromosomal Theory of Inheritance01:39

    Chromosomal Theory of Inheritance

    In 1866, Gregor Mendel published the results of his pea plant breeding experiments, providing evidence for predictable patterns in the inheritance of physical characteristics. The significance of his findings was not immediately recognized. In fact, the existence of genes was unknown at the time. Mendel referred to hereditary units as “factors.”
    The Ratio of X Chromosome to Autosomes02:45

    The Ratio of X Chromosome to Autosomes

    In most organisms, sex is determined by the ratio of X and Y chromosomes. However, in some organisms, such as Drosophila and C.elegans, sex is determined by the ratio of the number of X chromosomes to the number of sets of autosomes. The Y chromosome in Drosophila is active but does not determine sex. It contains genes responsible for the production of sperms in adult flies.  
    Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female Drosophila...
    Dosage Compensation02:50

    Dosage Compensation

    In animals, gender is determined by the number and type of sex chromosome. For example, human females have two X chromosomes, and males have one X and one Y chromosome, whereas C.elegans with one X chromosome is a male, and the one with two X chromosomes is a hermaphrodite.
    In addition to sexual development, the X chromosome has genes involved in autosomal functions such as brain development and the immune system. Therefore, males and females with  distinct numbers of X chromosomes will have...