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quester [9]
2 years ago
10

The appearance of free oxygen in the earths atmosphere led to the "great oxidation event" where did all of this oxygen come from

Biology
1 answer:
Alborosie2 years ago
8 0

Answer:

So there's a simple explanation for the Great Oxidation Event. It was the cyanobacteria, pumping out unwanted oxygen, that transformed Earth's atmosphere. ... That means the cyanobacteria were busy pumping out oxygen for at least half a billion years before oxygen started appearing in the air.

Explanation:

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Duchenne muscular dystrophy is an X-linked recessive disease. A phenotypically normal couple wants to start a family. The woman’
Andreyy89

Answer:

\frac{1}{8}

Explanation:

From the question: Duchenne muscular dystrophy is an X-linked recessive disease.

Now for an X-linked recessive disorder to be affected by a male individual; it only requires the presence of only one copy of the recessive allele of the disease to be present BUT in a female individual. both copies of the recessive allele must be present.

Let the X-linked recessive disease(i.e Duchenne muscular dystrophy) be = (ⁿ)

However, we are told that the couples are normal and are unaffected. Therefore;

the male partner (XY) will be:   X^NY

the female partner (XY) will be: X^NX^N

Similarly, the question proceeds by telling us that: the woman's brother has the disease.

Definitely, it's possible that this unaffected woman is a carrier of the disease.

So, if she is a carrier; we have her traits to be: X^NX^n

NOW, if a cross exist between these couples; we have

X^NY     ×        X^NX^n

                     X^N                         Y

X^N                X^NX^N                  X^NY

X^n                 X^NX^n                   X^nY

So, we have offspring as follows:

X^NX^N  = normal unaffected female  

X^NY     = normal unaffected male

X^NX^n   = female carrier for the Duchenne muscular dystrophy disease

X^nY      = affected male with the Duchenne muscular dystrophy disease

So, the probability of the child to be affected with the disease = \frac{1}{4}

Also, the probability that the first child will be a male or a female = \frac{1}{2}

∴

the  probability that the couple’s first child will be affected = \frac{1}{4}*\frac{1}{2}

=\frac{1}{8}

4 0
3 years ago
A virus is isolated, and individual virions appear spherical. what type of virus is this?
arlik [135]
This virus is Icosahedral
5 0
1 year ago
Population has a profound impact on what and the what
Andrej [43]

Answer:

this has a profound impact on population dynamics-age structure

Explanation:

6 0
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Explain where photosynthesis takes place? What is the function of this organelle?
Damm [24]

Answer:

Chloroplast

its function is to create chemical energy using light energy

Explanation:

Photosynthesis occurs in chloroplasts which can be compared to mitochondria because they both produce energy for the organism. The Chloroplast contains within it a pigment, chlorophyll which captures the sun's energy and turns into energy which is used to create other parts of photosynthesis. Chloroplasts capture light energy from the sun to produce the free energy stored in ATP and NADPH through a process called photosynthesis. Chloroplasts are one of the many organelles found in the body, and are generally considered to have originated as endosymbiotic cyanobacteria. In this aspect, they are similar to mitochondria but are found only in plants and protist.

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What is the role of capitulum in the body?
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The function of the capitulum, or elbow joint is to help the arm move efficiently and comfortably.
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