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3 years ago

Why are common names a problem for scientist?

1 answer:

4 0

It can be confusing because it isn't specific enough. In astronomy, the big dipper is not a spoon. It is a bear. Scientists know it as Ursa Major rather than a dipper or bear.

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Which protein serves as a chemical messenger? hemoglobin actin myosin insulin

kompoz [17]

Insulin is the correct answer.
Hope ti helped!

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3 years ago

Explain how the water vascular system allows an echinoderm to move along the ocean floor. Please help!

astra-53 [7]

Answer: Sea stars move using a water vascular system. Water comes into the system via the madreporite. It is then circulated from the stone canal to the ring canal and into the radial canals.

Explanation: The radial canals carry water to the ampullae and provide suction to the tube feet.

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3 years ago

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What is the effect of the biogeochemical cycles? cycling energy through a food chain recycling matter through the biosphere recy

jenyasd209 [6]

Answer:

Explanation:

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4 years ago

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When pink sweet peas were self-pollinated and the seeds were collected and sown, the following flower colors were obtained: Red

Pavlova-9 [17]

Answer:

c. 1:2:1

The results are consistent with incomplete dominance for this trait, with pink flowers being heterozygous.

Explanation:

If flower color were determined by a gene showing incomplete dominance, the possible genotypes and phenotypes are as follows:

RR- red
ww - white
Rw - pink

If pink sweet peas are self-pollinated, then a cross between two heterozygous individuals is done (Rw x Rw).

<u>From this cross the expected ratios are:</u>

1/4 RR (red)
2/4 Rw (pink)
1/4 ww (white)

So the null hypothesis is that the observed results exhibit a 1:2:1 ratio.

<h3><u>Chi square test</u></h3>

$X^{2} = \sum \frac{(Observed - Expected)^2}{Expected}$

<u>The observed frequencies were:</u>

34 Red
76 Pink
40 White

Total 150

<u>The expected frequencies for our null hypothesis are:</u>

1/4 x 150 = 37.5 Red
2/4 x 150 = 75 Pink
1/4 x 150 = 37.5 white

$X^{2} = \frac{(34- 37.5)^2}{37.5} + \frac{(76- 75)^2}{75} + \frac{(40- 37.5)^2}{37.5}$

$X^2=0.5067$

The degrees of freedom (DF) are calculated as number of phenotypes - 1; in this case DF = 3-1 = 2.

If we look at the Chi square table, for 2 DF and a probability of p0.05, the critical value is 5.991

Our X^2 value of 0.5067 is less than the critical value, so we do not reject the null hypothesis. The results are consistent with incomplete dominance for this trait, with pink flowers being heterozygous.

8 0

3 years ago

Please help due today!!<br> Brainliest given !!

Misha Larkins [42]

Answer:

The theory of evolution first formulated in Darwin's book is the process by which organisms change over time as a result of changes in heritable physical or behavioral traits that allow them to better adapt to its environment, survive and have more offspring.

Ernst Mayr divided Darwin's theory into 5 unique parts.

Ernst Mayr divided Darwin's theory into 5 unique parts.Evolution as such

Along with Buffon and Lamarck, Darwin supported the ability of species to change over time.

Common Descent

Darwin felt that all of the diversity of life on earth emerged out of the evolution from one or a few common ancestors.

Gradualism

While Lamarck felt that species-wide change could take place within the span of a few generations, Darwin felt evolution was a much slower process, taking place in innumerable small steps.

Population Speciation

This portion of Darwin's theory states that within a population, change in a species occurs as the balance of hereditary characteristics shifts across that population. This differs from Lamarck's idea that each individual in the population must undergo the same change. According to Lamarck, all giraffes living under tall trees would develop long necks. According to Darwin, some would randomly be born with long necks, this hereditary trait would gradually spread throughout the population.

Natural selection

Natural selection is often called the most unique part of Darwin's theory. Competition had been thought of as a reason that a given species might succeed or go extinct, but Darwin extended the understanding to change within a species. To continue the example of giraffes: when a giraffe is born with a longer neck than its fellows, it gains an advantage because it is able to reach more food. The long-neck giraffe is therefore stronger, lives longer, and more likely to have offspring. These offspring are born with the same long neck as their parent, though some might have even longer necks.

Returning to the example in the figure, in the first generation the application of the pesticide causes the death of most of the non-resistant insects: only those resistant to the pesticide survive. These insects reproduce and maintain their resistence so that the second generation will be more resistant than the first. So we have Natural selection, speciation, gradualism and evolution in act all together.

5 0

3 years ago