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Color Vision: Function of the human eye that is used in bright illumination or in daylight (at photopic intensities). Photopic vision is performed by the three types of Retinal cone photoreceptors with varied peak absorption wavelengths in the color spectrum (from violet to red, 400 - 700 nm).

Color Afterimages

JoVE 10194

Source: Laboratory of Jonathan Flombaum—Johns Hopkins University


Human color vision is impressive. People with normal color vision can tell apart millions of individual hues. Most amazingly, this ability is achieved with fairly simple hardware.


Part of the power of human color vision comes from a…

 Sensation and Perception

X-linked Traits

JoVE 10980

In most mammalian species, females have two X sex chromosomes and males have an X and Y. As a result, mutations on the X chromosome in females may be masked by the presence of a normal allele on the second X. In contrast, a mutation on the X chromosome in males more often causes observable biological defects, as there is no normal X to compensate. Trait variations arising from mutations on the X chromosome are called “X-linked”. One well-studied example of an X-linked trait is color blindness. When a mutation occurs in the genes responsible for red and green color vision in the photoreceptors of the retina, color blindness may occur. While this recessive mutation can cause females to be color blind, they must possess two mutated X chromosomes. Color blindness is much more common in males, who only have one X chromosome and therefore no second copy to potentially compensate for the mutation. Color blindness is passed from mother to son; a mutated X will be passed from the mother to half of her sons, who receive a Y from their father. Meanwhile, colorblind males will pass on the allele for color blindness to all of their daughters, who will be either carriers or color blind, depending on the maternal allele received. Occasionally, this type of X-linked mutation can also arise by spontaneous mutation and not as the result of inheritance from mother or

 Core: Classical and Modern Genetics

Crowding

JoVE 10280

Source: Laboratory of Jonathan Flombaum—Johns Hopkins University


Human vision depends on light-sensitive neurons that are arranged in the back of the eye on a tissue called the retina. The neurons, called the rods and cones because of their shapes, are not uniformly distributed on the retina. Instead, there is a region in the center…

 Sensation and Perception

Predator-Prey Interactions

JoVE 10996

Predators consume prey for energy. Predators that acquire prey and prey that avoid predation both increase their chances of survival and reproduction (i.e., fitness). Routine predator-prey interactions elicit mutual adaptations that improve predator offenses, such as claws, teeth, and speed, as well as prey defenses, including crypsis, aposematism, and mimicry. Thus, predator-prey interactions resemble an evolutionary arms race. Although predation is commonly associated with carnivory, for example, cheetahs hunting gazelles, a closely related type of interaction exists. Herbivory is the consumption of plants by animals known as herbivores. Plants typically deter herbivores by employing an array of defenses, including morphological defenses like an acacia tree’s thorns, and chemical defenses such as a milkweed’s toxins. However, some herbivores evolve adaptations to bypass plant defenses. Giraffes, for example, have long, dexterous tongues that allow them to consume the acacia’s leaves while avoiding its thorns. Monarch butterfly caterpillars evolved immunity to milkweed toxins, and instead ingest milkweed to store the toxins in their tissues as a defense against their own predators. Predator and prey population sizes can increase and decrease in cycles, due in part to predation. For instance, the lynx and snowshoe hare populations in northern

 Core: Population and Community Ecology

Probing the Limits of Egg Recognition Using Egg Rejection Experiments Along Phenotypic Gradients

1Department of Biology, Long Island University-Post, 2Department of Animal Biology, School of Integrative Biology, University of Illinois, 3Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 4Department of Zoology and Laboratory of Ornithology, Palacký University, 5Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic

JoVE 57512

 Behavior

Translational Brain Mapping at the University of Rochester Medical Center: Preserving the Mind Through Personalized Brain Mapping

1Department of Neurosurgery, University of Rochester Medical Center, 2Department of Psychology, Carnegie Mellon University, 3Public Relations and Communications, University of Rochester Medical Center, 4MOSS Rehabilitation Research Institute, Cognitive Neuroscience, 5University of Rochester Medical Center, 6Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center, 7Department of Imaging Sciences, University of Rochester Medical Center, 8Department of Neuroscience, University of Rochester Medical Center

JoVE 59592

 Neuroscience

Vibratome Sectioning Mouse Retina to Prepare Photoreceptor Cultures

1Department of Genetics, UMR_S 968, Institut de la Vision, 2Department of Visual Information, UMR_S 968, Institut de la Vision, 3Exploratory Team, UMR_S 968, Institut de la Vision, 4Sorbonne Universités, Paris 06, UMR_S 968, Institut de la Vision, 5INSERM, U968, Institut de la Vision, 6CNRS, UMR_7210, Institut de la Vision

JoVE 51954

 Neuroscience
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