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3 years ago

One particular feature found in bony fishes but is absent in cartilaginous fishes:

1 answer:

ioda3 years ago

7 0

A Swim Bladder is not present in cartilaginous fishes. Also called a fish maw or gas bladder the swim bladder is a gas-filled bladder that allows many bony fish to control their buoyancy by filling or releasing gas form the bladder. This allows them to change bouyancy without wasting metabolic energy by swimming.

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22. A plant geneticist is investigating the inheritance of genes for bitter taste (Su) and explosive rind (e) in watermelon (Cit

mylen [45]

Answer:

See the answer below

Explanation:

Using the formula for calculating Chi square ( $X^2$ ):

$X^2$ = $\frac{(O - E)^2}{E}$ where O = observed frequency and E = expected frequency.

The observed frequencies for the four phenotypes are 88, 62, 62, and 81 respectively.

For the expected frequency, the phenotypes are supposed to assort in 9:3:3:1 according to Mendel ratio.

Hence, expected frequencies are calculated as:

phenotype (1) = 9/16 x 293 = 164.81

phenotype (2) = 3/16 x 293 = 54.94

phenotype (3) = 3/16 x 293 = 54.94

phenotype (4) = 1/16 x 293 = 18.31

The $X^2$ is calculated thus:

Phenotype O E $X^2$

1 88 164.81 $\frac{(88 - 164.81)^2}{164.81}$ = 35.80

2 62 54.94 $\frac{(62 - 54.94)^2}{54.94}$ = 0.91

3 62 54.94 $\frac{(62 - 54.94)^2}{54.94}$ = 0.91

4 81 18.31 $\frac{(81 - 18.31)^2}{18.31}$ = 214.64

Total $X^2$ = 35.80 + 0.91 + 0.91 + 214.64 = 252.26

To the nearest tenth = 252

Degree of freedom = n - 1 = 4- 1 = 3

$X^2$ tabulated = 7.815

<em>The calculated </em> $X^2$ <em> exceeds the critical value, hence, the null hypothesis is rejected. The two genes did not assort independently. </em>

4 0

3 years ago

Which affect is one likely result of a forest fire

Luda [366]

One affect could be a loss of habitat for the animals that lived in that forest

6 0

3 years ago

Read 2 more answers

#43. three-year-old brittany is sobbing that her right arm is "gone," and the examinations shows her to have little muscle stren

Rom4ik [11]

The answer is Brachial Plexus. Brachial Plexus Injury is the result of pulling or stretching the arm forcibly. Sudden damage to the nerves, weakness, loss of sensation and movement are the most common symptoms of a brachial plexus injury.

4 0

3 years ago

The cells that respond to changes in blood gas concentration and generate the respiratory rhythm are found in several nuclei in

levacccp [35]

The answer is; medulla oblongata and pons.

In this region of the brain, there are chemoreceptors that can detect changes in the pH of the blood. These are called central chemoreceptor. There are also chemoreceptors in the arteries called peripheral chemoreceptors. When these chemoreceptors detect a drop in the blood PH (due to increased dissolved carbon dioxide in the blood), the depth and rate of breathing is increased in the lungs.

3 0

3 years ago

Explain the difference between independent variables, dependent variables, and control variables.

IgorC [24]

Answer:

Independent: Purposely altered

Dependent: Changes with respect to the independent being altered

Controlled: Never changes

Explanation:

An independent variable is a variable in which does not rely on other pieces/variables of an experiment to assume a value. In other words, it does not change when other variables change. However, it can be changed intentionally by the scientist.

A dependent variable is a variable in which its change in value relies on other pieces/variables of an experiment to assume a value. So, if the indeoendent variable is changed, the dependent variable will change as well. The opposite is not true though - if the dependent variable changes (for whatever reason), the independent variable hasn't necessarily been changed.

A controlled variable is a variable that stays CONSTANT throughout an experiment. It is never changed, and nothing will change it. An example of a control variable is the number of participants in a study: no more participants are being added, and no participants are being removed. The number of participants remains STATIC throughout the study.

3 0

3 years ago