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Alfred Lothar Wegener
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Alfred Lothar Wegener

Alfred Lothar Wegener (1880 - 1930) was a German meteorologist proponent of tectonic plate theory and continental drift. In the fall of 1911 in Marburg, Wegener was researching in the university library when he came across a scientific article that recorded fossils of identical animals and plants found on opposite sides of the Atlantic.

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Quantitative Inheritance

Quantitative inheritance is also a particular case of gene interaction. In this case, where the phenotypic differences of a given trait show no significant variations, the variations are slow and continuous and gradually change from a “minimum” phenotype to a “maximum” phenotype.
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Inheritance and sex

Under normal conditions, any human diploid cell contains 23 pairs of homologous chromosomes, ie 2n = 46. Of these chromosomes, 44 are autosomes and 2 are sex chromosomes also known as heterosomes. Autosomes and heterosomes Autosomal chromosomes are those related to characteristics common to both sexes, while sexual chromosomes are responsible for the characteristics of each sex.
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The RH blood group system

A third blood group system was discovered from experiments developed by Landsteiner and Wiener in 1940 with monkey blood of the genus Rhesus. These researchers found that by injecting the blood of this monkey into guinea pigs, antibodies were produced to combat the introduced red blood cells.
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Joints and Joints

Joint is the place where two or more bones join. Some joints, such as those of the skull, are fixed; in them the bones are firmly joined together. In other joints, called joints, bones are movable and allow the skeleton to perform movements. Ligaments The bones of a joint are held in place by the ligaments, resilient cords made up of fibrous connective tissue.
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Incomplete Dominance or Co-Dominance

Not all traits are inherited as the pea seed color, where the yellow color gene dominates over the green color gene. Very often, the combination of the different allele genes produces an intermediate phenotype. This situation illustrates the so-called incomplete or partial dominance.
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Probability notions applied to genetics

It is believed that one of the reasons Mendel's ideas remained misunderstood for over three decades was the mathematical reasoning they contained. Mendel assumed that gamete formation followed the laws of probability with respect to the distribution of factors. Probability Basics Probability is the chance that an event has to occur between two or more possible events.
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Glossary - Letter L

Lenticela - These are openings (cracks) in the rhytidome (rind) of vegetables. These openings allow the gas exchange in the region. Leukocytes - White blood cell; the white blood cell; There are several types of leukocytes, including neutrophils and lymphocytes; Its function is the defense of the body (phagocytosis and antibody production).
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Glossary - Letters I / J / K

Inclusion - Cytological technique whose purpose is to harden the biological material to allow thin sections (see also Microtome - special apparatus for this type of section). Insulin - Pancreatic hormone that lowers blood sugar. Interdigitations - Membrane specialization that increases the contact surface and adhesion between neighboring cells.
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Dense connective tissue

In dense connective tissue there is a predominance of fibroblasts and collagen fibers. Depending on how these fibers are organized, this fabric can be classified in different ways, as we will see below. Classifications: not modeled: formed by intertwined collagen fibers, arranged in bundles that do not have fixed orientation, which confers strength and elasticity.
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Glossary - Letter N

Nematoid - A worm-shaped animal that inhabits water or soil, which parasitizes plants and animals, including humans. Ecological niche - space occupied by an organism in the ecosystem, including its role in the community and its position in environmental gradients of temperature, humidity, pH, soil and other conditions of existence.
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Nervous tissue

Living things react to environmental stimuli. Changes in environmental conditions, such as sounds, shocks, heat and cold, are perceived by the body, which reacts by adopting a posture corresponding to the stimulus. Although it is the muscles that respond to the stimuli, it is the nervous tissue that is responsible for their reception and the choice of the appropriate response.
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Nerve impulse transmission

In a neuron, the stimuli always propagate in the same direction: they are received by the dendrites, travel through the cell body, travel through the axon and, from its end, are passed to the next cell (dendrite - cell body - axon). The nerve impulse that travels through the neuron is of electrical origin and results from changes in the electrical charges on the outer and inner surfaces of the cell membrane.
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Glossary - Letter T

Talophyte - A term that defines vegetables without conductive tissue and that do not distinguish the main body (stalk) from leaves and branches. Telocentric - Chromosome where the centromere is offset to the terminal part. (see centromere). Telophase - Last phase of cell division. It is characterized by chromosome despiralation, reorganization of the library, reappearance of the nucleolus and cytokinesis.
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The hole in the ozone layer

The ozone layer is a "layer" of this gas that surrounds the earth and protects it from various types of radiation, the main one being ultraviolet radiation, which is the main cause of skin cancer. In the last century, due to industrial development, products that emit chlorofluorocarbons (CFCs) have been used, a gas that upon reaching the ozone layer destroys the molecules that form it (O3), thus causing the destruction of this layer of the atmosphere.
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Size is not everything

Brazilian biologist says that in addition to the absolute weight, the concept of megafauna must take into account the relative impact of the animal on its ecosystem. Megafauna can be translated as "the set of giant animals". Although this definition may include dinosaurs, the term is most commonly used to refer to all large prehistoric animals that lived with the human species and disappeared at the end of the last Ice Age.
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External morphology of angiosperm plants

The body of most angiosperm plants is divided into two main parts, one located under the ground, consisting of the roots, and another area consisting of the stem, leaves, flowers and fruits. Root cells, as well as stem cells, do not photosynthesize and therefore depend on the food produced in the leaf cells.
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Cosmic panspermia or what?

To complete the 1920 theory of Aleksander I. Oparin (1894-1980) and English scientist John Burdon S. Haldane (1892 - 1964) about the origin of early living beings, Japanese researcher Yoshihiro Furukawa proposed that meteorite impacts on Earth's early oceans may also have been the cause of the formation of complex organic molecules that later originated life.
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Henrietta Lacks, the Immortal Woman

Have you ever wondered how to do research? For example, if we want to know what happens in our cells when a virus infects it, when we don't have a certain gene, or when we come in contact with a certain medicine. The first step is to have the cells to test, right? Well… what cells?
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Pseudofruits and parthenocarpic fruits

In pseudo-fruits, the edible portion does not correspond to the developed ovary. In cashews, floral peduncle hypertrophy occurs. In apple, pear and strawberry, it is the floral receptacle that develops. Thus, by eating the pulp of an avocado or mango, you are feeding on the true fruit. However, when savoring a cashew apple or an apple, you are chewing the pseudo fruit.
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Fruits and Seeds

Fruits arise from ovarian development, usually after egg fertilization. In general, the transformation of the ovary into fruit is induced by hormones released by developing embryos. There are cases, however, where fruit formation occurs without pollination. Fruit Parts A fruit is made up of two main parts: the pericarp, resulting from the development of the ovary walls, and the seeds, resulting from the development of fertilized eggs.
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