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Artificial Selection

Terms in this set (77)

What breed of domesticated turkey is the most commonly raised in the United States?
Broad-breasted white
From 1986 to 2006, the weight of the average broad-breasted white turkey jumped from 20 pounds to more than 28. True or False?
True
Compared to heritage breeds of the domestic turkeys, the _________________ has shorter legs, larger breasts, and white feathers than won't color the skin.
Broad-breasted white
Broad-breasted white turkeys are so oddly shaped that they can no longer breed and reproduce now solely by:
Artificial insemination
Broad-breasted white turkeys:
Cannot fly
2 MULTIPLE CHOICE OPTIONS
Compared to heritage breeds of domesticated turkeys, broad-breasted white turkeys grow twice as fast. True or False?
True
Compared to traditional breeds of domesticated turkeys, broad-breasted white turkeys have shorter lifespans due to obesity, joint problems, heart disease, and respiratory failure. True or False?
True
What process was used to transform the common turkey into the broad-breasted white?
Artificial selection
The produce available today is larger, easier to eat, and tastes better than the ancestral fruits and vegetables they are descended from. This change is the result of:
Artificial selection
Still life paintings from centuries past show how much fruits and vegetables have changed due to:
Artificial selection
Artificial selection is also known as:
Selective breeding
What common vegetable was likely cultivated in Asia minor in the 10th century and were either white or purple with thin forked roots and a strong flavor? (hint: today this vegetable is a large single root, orange in color, and tasty)
Carrot
An ________ is a specific set of instructions for carrying out a procedure or solving a problem
Algorithm
What algorithm have humans used to produced the plethora of varieties of domesticated plants and animals we see today?
Artificial selection
What two biological processes create diversity in populations?
Mutations and sexual reproduction
Mutations and sexual reproduction create_________ in populations.
Diversity
Russet Burbank
What variety of potato is shown here?
Most French fries today are made from what variety of potato
Russet Burbank
Luther Burbank developed the Russet Burbank potato to help with the devastating situation in Ireland following the Irish potato famine. His aim was to help "revive the country's leading crop." What disease was his potato resistant to?
Late blight
The Russet Burbank potato arose from two sporting events. The first was a chance sport of the Early Rose variety that was bigger and Late blight resistant. The second was a chance sport that had:
Russeted skin
Varieties often originate from a _________; an individual organism that abruptly deviates from type.
Sport
Sports are organisms that have a novel feature that a breeder deems desirable. What is the source of most sports?
Mutations
What breed of cat originated from a sport named Shulamith, a stray found in Los Angeles back in 1981?
American curl
American curl
Name this breed of cat.
What breed of cat originated from a sport named Susie, found on a Scottish farm in 1961?
Scottish fold
The modern ________ arose from a cross between a pomelo and a sweet orange in the Caribbean in the 17th-18th century.
Grapefruit
Most of the two dozen or more varieties of grapefruit arose from:
Sports
By the late 1800s, grapefruit trees were being cultivated in southern Texas; by 1910, grapefruit was a major commercial fruit in the Rio Grande Valley, Arizona and California as well as Florida. The pink grapefruit and other varieties were developed, and in 1929 a Texas citrus grower discovered a mutated red grapefruit randomly growing on a pink grapefruit tree, which became the popular ________________________
Ruby Red Grapefruit
Compared to today's grapefruit, the original was about the size of an orange, seedy, and very bitter. True or False?
True
Domesticated pigeons are all descended from the common:
Rock dove
What breed of pigeons have double the number of tail feathers as a regular pigeon?
Fantail pigeon
Name this breed of pigeon. (FYI Darwin kept this variety for several years while researching artificial selection)
Fantail pigeon
The initial yield of the antibiotic penicillin in the 1930's was one unit of penicillin to ________________ units of Penicillium mold.
One million
How did they first increase the yield of penicillin from Penicillium mold from 1 to a million units to 1 to 25,000 units (40x improvement)?
They found a different species with a higher yield (Penicillium chrysogenum)
Although Penicillium chrysogenum yielded 40x more penicillin than the original species used, Penicillium rubens, it was still not enough for commercial mass production. So what process did they use to increase the yield of Penicillium chrysogenum?
Mutation breeding
Mutation breeding is founded on the idea that if you increase the mutation rate, you can get a larger the pool of possible beneficial mutants. True or False?
True
What mutagen was used on Penicillium chrysogenum to increase the number of possible beneficial sports in the search for higher yields of penicillin?
X-rays
Mutation breeding has two steps. The first step is to expose an organism to a mutagen to increase the number of sports. What is the second step?
Screen the survivors for a sport with a trait superior to the original
Mutation breeding depends on the same two processes as artificial selection and natural selection: variation and __________.
Selection
Through mutation breeding, penicillin yield increased from 40 times to 240 times the yield of the original Penicillium rubens mold. True or False?
True
The second major improvement in penicillin yield produced 240x more than the original P. rubens strain. So rather than a yield ratio of 1 unit of penicillin to 1 million units of mold, the final yield ratio ended up to be 1 unit of penicillin to:
4000 units of mold
Several varieties of grapefruit (e.g. Star Ruby) were created by mutation breeding by ___________ seeds, planting them, and screening the survivors for superior traits.
Irradiating
From 1930 to 2014 more than 3200 plant varieties have been developed by mutation breeding and released to the public. True or False?
True
What makes artificial selection different from natural selection?
Humans are in control of the gene pool in artificial selection
Selective breeding (artificial selection) is when a human selects what breeds with what to attain a trait the human finds desirable. True or False?
True
Giant pumpkins grow to enormous sizes largely in part due to ______ and not Miracle-Gro.
Genetics
World Record weights of giant pumpkins have been broken every few years over the last few decades. The current record holders (2021) weigh over a ton. True or False?
True
Describe the process of selective breeding for large size in giant pumpkins.
The largest pumpkins from around the world are selected and bred. The largest offspring from these matings are crossed. The cycle continues with each generation of giant pumpkin.
Artificial selection of giant pumpkins has steadily and gradually increased the size of the World Record holders over the years. What does this fact tell us about the genes involved in pumpkin growth?
The gradual increase in size indicates that pumpkin size is polygenic and quantitative.
Will giant pumpkins continue to get bigger indefinitely through selective breeding?
No. Eventually, giant pumpkin size will plateau and max out near the morphological limit of the plant.
The variety of dogs created through artificial selection is astounding. We now have toy dogs that weigh less than 10 pounds and large dogs that weigh in at over 100. These changes are reflected in skeletal differences in the number of teeth and tail bones between some breeds. Darwin argued that is an alien paleontologist compared the bones of these two animals, they would classify them as:
Separate species
The modern bulldog is significantly different from its ancestors 200 years ago. Selective breeding has resulted in an animal with a slew of health problems and a shorter lifespan. True or False?
True
Cabbage, broccoli, cauliflower, Brussel sprouts, and kale are all members of the same species. True or False?
True
Broccoli, cauliflower, and kale are some of the many vegetables that have been selected from one species of wild mustard. By selecting variations in different parts of the plant, breeders have obtained these divergent results. This best describes:
Artificial selection
In a scientific study of artificial selection in the 1950s, __________ were selectively bred for the most bristles on their bodies. After 35 generations, the experimental group had, on average, double the number (87) of bristles compared to the control group (39). Some members of the experimental group had more than one hundred bristles.
Fruit flies
In a scientific study of artificial selection in the 1950s, ______ were selectively bred for the least number of bristles on their bodies. After 35 generations, the experimental group had, on average fewer than half the number (11) of bristles compared to the control group (39). Some members of the experimental group had zero bristles.
Fruit flies
Bull Terrier
Name this dog breed whose skull shape was gradually changed through artificial selection.
What kind of fox was domesticated by Russian scientists in the 20th century through selective breeding?
Silver foxes
What trait was selected for in the silver fox domestication experiment done by Russian scientists in the 20th century?
Lack of aggressive behavior toward humans
Selection breeding for tame behavior in silver foxes over generations resulted in foxes happy to be held, petted, and played with by humans. True or False?
True
What other features changed as the silver foxes were selectively bred for tameness?
Floppy ears, curly tails, and fur color variations
The accompanying physical changes that occur with the selection for tameness in silver foxes is an example of:
Domestication syndrome
Domestication syndrome describes a common suite of _________ that accompany human selection for the calmest, most prosocial-toward-human animals.
Traits
The common ancestor of modern corn is __________ a plant native to central Mexico.
Teosinte
Modern corn has a single stalk whereas teosinte has a:
many-branching stalk
Unlike the soft kernels of modern corn, teosinte kernels are covered by a hard covering called a:
Pericarp
An ear of modern corn has close to a thousand kernels arranged in multiple rows. An ear of Teosinte has:
Less than ten kernels arranged in a single row
George Beadle hypothesized that teosinte was the ancestor to modern corn because:
Their chromosome number and morphology are very similar and they can cross-breed.
George Beadle wanted to see how many genes changed to evolve teosinte into modern corn. So he crossed teosinte with corn and then crossed their offspring (F2). By counting the number of F2 offspring that looked just like corn or teosinte versus to total number of F2 offspring, Beadle discovered that ______________ of the F2 were just like the parent plants.
1 in 500
The ratio of 1 out of 500 F2 that resembled the parent phenotypes, indicated to Beadle that the number of genes altered by artificial selection in the evolution of corn was between:
4 and 5
What kind of genes were altered in the selective breeding of teosinte to modern corn?
Regulatory genes
What happens if you place a copy of teosinte's branching gene into a modern corn plant?
The corn plant with have a branching stalk
What happens if you place a copy of modern corn's pericarp gene into a teosinte plant?
The hard pericarp opens exposing the kernel
Molecular clock analysis of corn and teosinte indicate that their divergence occurred ___________ years ago.
9,000
Who selectively bred teosinte into modern corn?
Native people of Mexico
Archeological analysis of ____________ from rock shelters indicate native Mexicans were processing and consuming corn 9,000 years ago.
Grinding stones
Since the pericarp of teosinte is tough, how may have native Mexicans processed them for consumption?
Pop them like popcorn
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