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3 years ago

How could genetic drift explain differences in the genotype frequencies among the caucasian and aborigine populations?

1 answer:

7 0

Genetic drift occurs when there is no random mating across a population. This causes a change in allelic frequency due to a random sampling of the population.

As the aboriginal population explored the earth, a small part of the population became geographically isolated either due to continental drift and climate changes. As the isolated population grew bigger, they established their own gene pool. This resulted a change in genotypic frequencies from that of the aboriginal population.

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Industrial melanism refers to the dark pigmentation that evolved in some insects giving them protective coloration on vegetation

Natalka [10]

Answer:

The frequency of the dominant allele, p = 0.542

The proportion of black moths that are heterozygous 2pq = 0.496

Explanation:

According to Hardy-Weinberg, the allelic frequencies in a locus are represented as p and q, referring to the allelic dominant or recessive forms. The genotypic frequencies after one generation are p² (Homozygous dominant), 2pq (Heterozygous), q² (Homozygous recessive). Populations in H-W equilibrium will get the same allelic frequencies generation after generation. The sum of these allelic frequencies equals 1, this is p + q = 1.

In the same way, the sum of genotypic frequencies equals 1, this is

p² + 2pq + q² = 1

Being

p the dominant allelic frequency,

q the recessive allelic frequency,

p² the homozygous dominant genotypic frequency

q² the homozygous recessive genotypic frequency

2pq the heterozygous genotypic frequency

In the exposed example, 79% of the moths of the species Biston betularia were black due to the presence of a dominant gene for melanism.

If the genotypic frequency of back moths is 0.79, then, by performing the following equation we can get the not-black moths genotypic frequency:

p² + 2pq + q² = 1

where p² is the homozygous dominant genotypic frequency, q² the homozygous recessive genotypic frequency, and 2pq is the heterozygous genotypic frequency.

As 0.79 is the phenotypic frequency of black moths, then this frequency equals p²+2pq.

Clearing the equation:

p² + 2pq + q² = 1

0.79 + q² = 1

q² = 1 - 0.79

q² = 0.21

The genotypic frequency of non-black moths is 0.21. So, from here we can calculate the allelic frequency:

q² = 0.21

q= v 0.21

q = 0.458

If 0.46 is the allelic frequency of non-black moths, then by clearing the equation p + q = 1, we can get the p allelic frequency:

p + q = 1

p + 0.458 = 1

p = 1 - 0.458

p = 0.542

The genotypic frequency p² = (0.542)² = 0.294

The heterozygote genotypic frequency

2 x p x q = 2 x 0.542 x 0.458 = 0.496

Finally, we can check this answer by clearing the following equation:

p² + 2pq + q² = 1

0.294 + 0.496 + 0.21 = 1

4 0

3 years ago

The allele that codes for "having freckles" is dominant (f) over the allele that codes for "no freckles" (f). a heterozygous, fr

Inessa05 [86]

1/2 is the correct answer
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8 0

3 years ago

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What is true of the work for all scientists?

snow_tiger [21]

The correct answer for this question is A - Scientists ask testable questions and devise ways in which they can answer those questions through experimentation or observation. The rest of the possible answers for this question only describe some scientists.

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3 years ago

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At the beginning of Unit 3 we saw the example of the pygmy seahorse, whose offspring can change their body color, depending on t

Brut [27]

Answer:

Seahorses are between the sea animals that may modification color. Such variations camouflage the creatures if not obscure or perhaps frighten possible predators. Color variations facilitate seahorse’s link emotions and intentions, particularly throughout suit. Whereas these alterations are stunning and infrequently seem seamless, they're truly the merchandise of complicated interactions between the seahorse's brain and small organs carried within its skin.

Anatomy

Seahorse organelles, known as chromatophores, are enclosed at intervals their skins. These tiny, sack like organs contain variety of pigments and may expand or consent response to a spread of stimuli, inflicting the seahorse to vary color. Typically, seahorses carry solely a couple of chromatophore diversities, so completely different colors are created through the blending and matching of accessible pigments.

Building Color

All of the colours to that a seahorse will modification are derived from 3 or four basic stains contained in several chromatophores. The pigment cells of those chromatophores are sometimes stacked on prime of every alternative or clustered along in teams. the colour a seahorse displays is predicated on sort, combination and attentiveness of those cells, moreover as their proximity to the skin's surface.

Brightness and Tone

Muscles hooked up to chromatophores will push stain cells toward, or pull coloring cells off from, the surface of a seahorse's skin. Once the coloring is on the point of the skin's surface, the animal's color is brighter and splendid. In turn, once the pigment attracts off from the skin's surface, the ensuing color is a smaller amount saturated and somewhat boring.

Speed of modification

Depending on the stimulant that causes a seahorse to vary its color, chromatophores are measured by the seahorse's system or by its secretion fluctuations. once the system activates chromatophores, comparable to in life-and-death things, the animal's color changes quickly. once chromatophores are activated by secretion fluctuations, comparable to once a seahorse is suit a mate, the animal's color in its place changes somewhat slowly.

Both of them aren't subjected to action because the color modification in ocean horse are influenced by system and secretion system.

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3 years ago

ANYONE PLSSSS!!!!

Tatiana [17]

Answer:

There are many invasive animal sand plants which are harmful for native flora and fauna. Some of the invasive or alien species are as following:

1. The Nile Perch: Nile Perch is a type of fish which is native to African lake and river systems but if it is introduced in other countries lake it can be dangerous to other fishes in that lake. It was earlier introduced to Lake Victoria but after sometime it was evaluated that native fishes got extinct and the Nile Perch become very huge in size.

2. The cotton whitefly: Cotton whitefly are native to India but now can be found on most of the continents and have very bad impact on the fauna or agricultural plants. They have capability of transmitting upto 100 different plant viruses. find them thriving

3. The desert locust: The desert locust is a species of locust which can fly and are one of the most disastrous migratory pests in the world. They feed over green green vegetation, including pasture, crops and fodder. They have very bad impact on native flora as they are migratory pests. They are found in Africa and migrated to nearby countries such as India and damages the native flora.

4. European starlings: European starlings are the bird species which fight with native species for food and shelter. They are found in Alaska and Mexico and proved invasive in U.S. as the number of native birds decreased with their introduction.

4 0

3 years ago