16 résultats pour "crossing"

• Crossing over

  inchangés : ceux du père et ceux de la mère échangent leur matière. 1.1 en résulte des chromosomes nouveaux concentrant, au hasard des croisements, des caractéris­ tiques · capables de déterminer conjointement le dévelop­ pement d'individus particulièrement bien adaptés à l'en­ vlronnement. Au cours de la méiose et avant la réduction par deux de leur nom'bre, les c

• crossing-over.

• Puzzle.

  Visual puzzles involve searching a picture to find hidden or disguised figures or answering a question about some part of a visual illusion. For instance, the popular 19th- century prints of American lithographic company Currier & Ives featured hidden people, animals, and other objects. A 16th-century painting from Bukhara, Uzbekistan,of a camel includes hidden figures of 17 people, 10 rabbits, a monkey, and a dragon (Metropolitan Museum of Art, New York City). B Mathematical Puzzles and Logic...

• Christopher Columbus I INTRODUCTION Christopher Columbus (1451-1506), Italian-born Spanish navigator who sailed west across the Atlantic Ocean in search of a route to Asia but achieved fame by making landfall in the Americas instead.

  explorers, adventurers, entrepreneurs, merchants, and any others who saw their fortunes tied to the trade winds and ocean currents. Columbus’s brother Bartholomewworked in Lisbon as a mapmaker, and for a time the brothers worked together as draftsmen and book collectors. Later that year, Columbus set sail on a convoy loadedwith goods to be sold in northern Atlantic ports. In 1478 or 1479 Columbus met and married Felipa Perestrello e Moniz, the daughter of a respected, though relatively poor, nob...

• Christopher Columbus.

  explorers, adventurers, entrepreneurs, merchants, and any others who saw their fortunes tied to the trade winds and ocean currents. Columbus’s brother Bartholomewworked in Lisbon as a mapmaker, and for a time the brothers worked together as draftsmen and book collectors. Later that year, Columbus set sail on a convoy loadedwith goods to be sold in northern Atlantic ports. In 1478 or 1479 Columbus met and married Felipa Perestrello e Moniz, the daughter of a respected, though relatively poor, nob...

• Christopher Columbus.

  explorers, adventurers, entrepreneurs, merchants, and any others who saw their fortunes tied to the trade winds and ocean currents. Columbus’s brother Bartholomewworked in Lisbon as a mapmaker, and for a time the brothers worked together as draftsmen and book collectors. Later that year, Columbus set sail on a convoy loadedwith goods to be sold in northern Atlantic ports. In 1478 or 1479 Columbus met and married Felipa Perestrello e Moniz, the daughter of a respected, though relatively poor, nob...

• Christopher Columbus - explorer.

  explorers, adventurers, entrepreneurs, merchants, and any others who saw their fortunes tied to the trade winds and ocean currents. Columbus’s brother Bartholomewworked in Lisbon as a mapmaker, and for a time the brothers worked together as draftsmen and book collectors. Later that year, Columbus set sail on a convoy loadedwith goods to be sold in northern Atlantic ports. In 1478 or 1479 Columbus met and married Felipa Perestrello e Moniz, the daughter of a respected, though relatively poor, nob...

• Meiose

  BRASSAGES ET DIVERSITE DES GAMETETES (1) 1 Le brassage intra-chromosomique Au début de la méiose, en prophase I, des échanges de fragments de chromatides, donc des échanges d’allèles, se produisent entre les chromosomes homologues appariés : c’est le crossing-over . Au cours du crossing-over, l’échange d’allèles est à l’origine d’une nouvelle combinaison d’allèles, différente de la combinaison d’allèles parentale : on parle...

• Aboriginal Australians - history.

  Current archaeological evidence suggests that human occupation of Australia began around 50,000 to 60,000 years ago. The first settlers are believed to havemigrated from Southeast Asia in gradual stages, by way of the islands of Indonesia. Around 50,000 years ago sea levels were as much as 120 m (390 ft) lower thanthey are today, and Australia was joined with New Guinea and Tasmania to form one giant landmass called Sahul, or Greater Australia. Scholars believe that the firstmigrants to Sahul ca...

• Yangtze - Geography.

  A Agriculture and Industry Today about 400 million people, or about one-third of the population of China, live in the Yangtze Basin. Many are engaged in agriculture. The basin contributes nearlyhalf of China’s crop production, although only one-quarter of the basin is arable. The most fertile areas for farming are the Sichuan Basin, the plains between theYangtze and its tributary the Han, and the plains of the lower basin. In all about 40 percent of the cereals, more than 30 percent of the cott...

• D-Day Invasion.

  The Allied planners focused on the beaches around Caen and the Cotentin Peninsula in northern France rather than those of Calais, even though it meant the forcewould be crossing at a wider part of the English Channel. That disadvantage was far outweighed by what the site offered: comparatively scanty defensive fortificationsand beachhead ideally suited for successful exits. The clincher was an isolated battlefield that the Germans would have difficulty reinforcing. The date was set for May 1, 19...

• Cyprus - country.

  40,000 cubic meters (1.4 million cubic feet) of salt water into fresh water per day, opened at Dhekelia in 1997, and a second larger plant opened at Larnaca in 2001. III PEOPLE OF CYPRUS The combined population of the Greek and Turkish sectors (2008 estimate) is 792,604. The overall population density is 86 persons per sq km (222 per sq mi). About69 percent of the island’s inhabitants live in urban areas. Greek-speaking Cypriots make up approximately 85 percent of the population. About 12 perc...

• Atlantic Slave Trade.

  members of the planters’ society. Through most of the years of the Atlantic trade, prices for Africans remained favorable in relation to the price of the crops theyproduced. They were, thus, the best economic solution for plantation owners seeking inexpensive labor. The Atlantic slave trade began as a trickle in the 1440s and grew slowly through the 17th century. By 1700, 25,000 slaves, on average, were crossing the Atlantic everyyear. After 1700 the trade grew much more rapidly to a peak in the...

• Ice Skating.

  cold climate. Competitors for these events are chosen from the best skaters in each participating country, usually through preliminary national competitions. Speedskaters also compete on a World Cup circuit, which pits the world’s best skaters against one another during the year. A Figure Skating The major types of competitive figure skating are individual men’s and women’s competitions, pairs skating, ice dancing, and precision skating. In individualcompetitions a single skater performs requir...

• Horse - biology.

  Horses reach sexual maturity at about one and a half years. The estrous cycle in the mare—a mature female horse—typically lasts 21 days. During the first five days ofthe cycle, the mare is usually receptive to mating. The estrous cycle stops during winter and resumes in the spring, which is the start of the breeding season. Astallion—a mature male horse—approaching a mare in estrus engages in various courtship rituals. These include uttering nickering sounds and sniffing and licking themare’s ge...

• On the road