crossing

Examples of crossing in the following topics:

• The Cross Product

  • The cross product of two vectors is a vector which is perpendicular to both of the original vectors.
  • The cross product is a binary operation of two three-dimensional vectors.
  • If the two original vectors are parallel to each other, the cross product will be zero.
  • The cross product is denoted as $a \times b = c$.
  • The geometric method of finding the cross product uses the magnitudes of the vectors and the sine of the angle between them:

• The Punnett Square Approach for a Monohybrid Cross

  • Mendel performed seven monohybrid crosses involving contrasting traits for each characteristic.
  • Recall that Mendel's pea-plant characteristics behaved in the same way in reciprocal crosses.
  • Called the test cross , this technique is still used by plant and animal breeders.
  • In a test cross, the dominant-expressing organism is crossed with an organism that is homozygous recessive for the same characteristic.
  • This cross produces F1 heterozygotes with a yellow phenotype.

• Mendelian Crosses

  • Mendel's crosses involved mating two true-breeding organisms that had different traits to produce new generations of pea plants.
  • Mendel performed crosses, which involved mating two true-breeding individuals that have different traits .
  • Plants used in first-generation crosses were called P0, or parental generation one, plants.
  • Mendel collected the seeds belonging to the P0 plants that resulted from each cross and grew them the following season.
  • In one of his experiments on inheritance patterns, Mendel crossed plants that were true-breeding for violet flower color with plants true-breeding for white flower color (the P generation).

• Cross-Functional Teams

  • A cross-functional team comprises people from different departments and with special areas of expertise working to achieve a common goal.
  • Many business activities require cross-functional collaboration to achieve successful outcomes.
  • This can make communication between members of a cross-functional team difficult and subject to misunderstanding.
  • Cross-functional teams may be more likely than less complex teams to have members with divergent perspectives on how work gets done.
  • Perceived differences in relative importance or credibility can undermine the effectiveness of cross-functional collaboration.

• Cross-Price Elasticity of Demand

  • The cross-price elasticity of demand shows the relationship between two goods or services.
  • Cross-Price Elasticity of Demand (EA,B) is calculated with the following formula:
  • The value of the cross-price elasticity for complementary goods will thus be negative .
  • A positive cross-price elasticity value indicates that the two goods are substitutes.
  • In the case of perfect substitutes, the cross elasticity of demand will be equal to positive infinity .

• Hatching and Cross-Hatching

  • Hatching and cross-hatching are artistic techniques used to create tonal, shading, and textural effects by drawing closely spaced parallel lines.
  • Hatching and cross-hatching are artistic techniques used to create tonal, shading and textural effects by drawing closely spaced parallel lines.
  • Cross-hatch lines are used to provide additional tone and texture and can be oriented in any direction, often overlapping each other to create heavily shaded areas.
  • Multiple layers of cross-hatch lines can give rich and varied shading to objects by manipulating the pressure of the drawing tool to create a large range of values.
  • Albrecht Dürer uses hatching and cross-hatching in both the background and foreground of this image.

• Control of Muscle Tension

  • Muscle tension is influenced by the number of cross-bridges that can be formed.
  • In individual muscle fibers, the amount of tension produced depends primarily on the amount of cross-bridges formed, which is influenced by the cross-sectional area of the muscle fiber and the frequency of neural stimulation.
  • The number of cross-bridges formed between actin and myosin determine the amount of tension that a muscle fiber can produce.
  • Cross-bridges can only form where thick and thin filaments overlap, allowing myosin to bind to actin.
  • If more cross-bridges are formed, more myosin will pull on actin and more tension will be produced.

• ATP and Muscle Contraction

  • ATP is critical for muscle contractions because it breaks the myosin-actin cross-bridge, freeing the myosin for the next contraction.
  • As soon as the actin-binding sites are uncovered, the high-energy myosin head bridges the gap, forming a cross-bridge.
  • After the power stroke, ADP is released, but the cross-bridge formed is still in place.
  • ATP can then attach to myosin, which allows the cross-bridge cycle to start again; further muscle contraction can occur.
  • The cross-bridge muscle contraction cycle, which is triggered by Ca2+ binding to the actin active site, is shown.

• Mendel's Law of Independent Assortment

  • The independent assortment of genes can be illustrated by the dihybrid cross: a cross between two true-breeding parents that express different traits for two characteristics.
  • For more complex crosses, the forked-line and probability methods are preferred.
  • For a trihybrid cross, the F2 phenotypic ratio is 27:9:9:9:3:3:3:1.
  • The forked-line method can be used to analyze a trihybrid cross.
  • This dihybrid cross of pea plants involves the genes for seed color and texture.

• Switching Parties

  • For these reasons, it is fairly uncommon for a Member of Congress to cross over parties, but it is not unheard of.
  • A member might switch parties, or "cross the floor," for a number of reasons.
  • Crossing over can cause difficulties.
  • For example, when Ben Nighthorse Campbell crossed to the Republican party after being elected as a Democratic Senator, much of his Congressional staff quit.
  • Senator Lieberman was a Democrat, then crossed over as an Independent, then endorsed a Republican presidential candidate.