They are the skeletal muscle tissues
A person who has a recessive trait must have two<span> recessive alleles because - A dominant allele does not let a recessive trait show up, in other words it simply dominates and… over shadows the recessive trait.</span>
nebular hypothesis
The most widely accepted theory of planetary formation, known as the nebular hypothesis, maintains that 4.6 billion years ago, the Solar System formed from the gravitational collapse of a giant molecular cloud which was light years across. Several stars, including the Sun, formed within the collapsing cloud.
Answer: Imagine life without your best friend. Who would you hang out with and talk to about your problems? Life would be so lonely! You rely on your friends for companionship, fun, and support. Animals rely on each other, too. Some have lifelong relationships with other organisms, called symbiotic relationships. There are three different types of symbiotic relationships: mutualism, commensalism, and parasitism.
Mutualism: both partners benefit. An example of mutualism is the relationship between the Egyptian plover and the crocodile. In the tropical regions of Africa, the crocodile lies with its mouth open. The plover flies into its mouth and feeds on bits of decaying meat stuck in the crocodile’s teeth. The crocodile does not eat the plover. Instead, he appreciates the dental work. The plover eats a meal and the crocodile gets his teeth cleaned. Coincidentally, the Egyptian plover is also known as the crocodile bird.
Commensalism: only one species benefits while the other is neither helped nor harmed. For example, remora fish are very bony and have a dorsal fin (the fin on the back of fish) that acts like a suction cup. Remora fish use this fin to attach themselves to whales, sharks, or rays and eat the scraps their hosts leave behind. The remora fish gets a meal, while its host gets nothing. Selfish, sure, but neither gets hurt.
Parasitism: One organism (the parasite) gains, while the other (the host) suffers. The deer tick is a parasite. It attaches to a warmblooded animal and feeds on its blood. Ticks need blood at every stage of their life cycle. They also carry Lyme disease, an illness that can cause joint damage, heart complications, and kidney problems. The tick benefits from eating the animal's blood. Unfortunately, the animal suffers from the loss of blood and nutrients and may get sick.
Answer:
In the mid-1800s, over-hunting of Northern Elephant Seals reduced their population size to fewer than 40 individuals. However, the population has since rebounded to over 100,000 animals. The population went through a _<u>bottle neck event (genetic drift)</u>_, which makes it more susceptible to _<u>developing a genetic disease</u>_.
Explanation:
Genetic drift is the random change that occurs in the allelic frequency of a population through generations. The magnitude of this change is inversely related to the size of the original population. These changes produced by genetic drift accumulate in time. Eventually, some alleles get lost, while some others might set. Genetic drift affects a population and reduces its size dramatically due to a disaster or pressure-bottleneck effect- or because of a population split -founder effect-
. The bottleneck effect most likely affects smaller populations.
In the exposed example, extensive hunting acted as a pressure that reduced the number of Northern elephant seals to fewer than 100. This population experienced one or many generations of small size since these animals were affected by hunting. As the survivors did not have the whole genetic pool of the original population, the <em>population size might have recovered to a current population size of 100,000 individuals</em><em>,</em><em> but the genetic pool might have not</em><em>.</em> When the small population increases in size, it will have a genetically different composition from the original one. In these situations,<em> there is a reduced genetic variability, with a possibility of developing a peculiar allelic component</em>. If the <em>survivors in the population carried or developed a mutation, probably this mutation passed from generation to generation</em>. It will involve <em>more individuals each time and</em><em> increase the probability of developing a genetic disease.</em>
