On average, the adult brain loses _____ percent of its weight between the ages of 20 and 90.

Based on the information in the table, which of the following changes is least likely to produce a phenotypic

yaroslaw [1]

GAU to GAC is least likely to change phenotype of an organism.

<h3><u>Explanation</u>:</h3>

Phenotype of an organism is defined as the physical characteristics of an organism. This phenotype is dependent on the genotype of the organisms. This means the phenotypic characters are actually the expressions of the genes of the organisms. Now the genes are expressed in form of codons that are the three nitrogen base sequences. Each codon codes for a particular amino acid which in turn polymerises to from the protein which actually forms the phenotype of the organism.

Now there are 20 amino acids and 64 codons. Thus there are more than 1 codons for a single amino acid. So, if a codon is replaced by another codon which codes for same amino acid, then the phenotype is least likely to be affected.

Both the GAU and GAC codes for aspartic acid. So the phenotype won't be affected much by this mutation

5 0

3 years ago

there are multiple chickens and rabbits in a cage there are 72 heads and 200 feet inside of the cage how many chickens are in th

schepotkina [342]

The answer is 44 chickens and 28 rabbits.

We have a system of two equations.
x - the number of rabbits
y - the number of chickens

Both chicken and rabbit have only 1 head, so the first equation is: x + y = 72.
Since rabbits have 4 legs and chickens 2 legs, the second equation is: 4x + 2y = 200.

Now, let's solve the system:
x + y = 72
4x + 2y = 200
___________
y = 72 - x
⇒ 4x + 2 · (72 - x) = 200
4x + 2 · 72 - 2 · x = 200
4x + 144 - 2x = 200
2x + 144 = 200
2x = 200 - 144
2x = 56
⇒ x = 56 ÷ 2 = 28
So, there are 28 rabbits.

Since
y = 72 - x = 72 - 28 = 44,
there are 44 chickens.

7 0

3 years ago

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

Flowers of orchid species Ophrys bombyliflora look and smell like female bumblebees. This attracts the male bumblebees flying ne

balandron [24]

I would say A) Coevolution because the two species would evolve in response to one another. Flowers and their pollinators must evolve together. For example, if the flower has a mutation that no longer attracts the bumblebees, it will not reproduce. Then the hummingbird would have to find a new food source.

7 0

3 years ago

Construction contributes to soil erosion because...

Mamont248 [21]

Construction contributes to soil erosion because;

C. It removes vegetation from the building site.

8 0

3 years ago

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