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2 years ago

Use the mechanisms of meiosis to explain why most mules are sterile.

Biology

1 answer:

Tema [17]2 years ago

4 0

Answer:

3. An even number of chromosomes are required for synapsis during prophase I and proper pairing during metaphase

Explanation:

Mules are hybrids of a cross between a female horse and a male donkey. Horses contain 64 chromosomes while donkeys contain 63 chromosomes in their somatic cells respectively. This means that they each produce 32 and 31 chromosomes respectively during meiosis. A mule, hence, contains 32+31= 63 chromosomes in their somatic cells.

This chromosome number in mules are uneven for meiosis to occur because meiotic division requires that an even number of homologous chromosomes pair together in a process called SYNAPSIS during prophase I of meiosis I. This is impossible in a mule because of the uneven number of chromosomes in its cells.

Also, during metaphase of meiosis, the homologous chromosomes need to be properly aligned at the equator for separation to occur. This is also impossible in a mule considering the number of chromosomes that don't add up.

Due to this reason of unevenness in the number of chromosomes present in a mule, meiosis will not occur and if meiosis (gamete formation) does not occur, reproduction cannot take place. Therefore, the mule is a sterile species i.e. cannot produce offsprings via sexual reproduction.

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Select all that apply. Which of the following products are derived from invertebrates? food shell jewelry silk cotton

asambeis [7]

The products that are derived from invertebrates are the following:
1. food - crabs, lobsters, oysters, octopuses: all of these are invertebrates (meaning they have no spine) and are used as food
2. shell - seashells are invertebrates and their shells are used for various purposes
3. jewelry - shells are used as jewelry, as well as pearls coming from seashells
4. silk - silk comes from silkworms, which are invertebrates
I just wouldn't pick cotton, because you get cotton from a plant.

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3 years ago

How does the Griffith experiment connect to the Meselson & Stahl experiment? How does this experiment support Meselson &

Nataliya [291]

Answer:

CHALLENGE ACCEPTED!!

Explanation:

THE GRIFFITH EXPERIMENT demonstrated that something in the virulent s strain of pneumococcus could transform non virulent r strain bacteria into a lethal form, even when the s strain bacteria had been killed by the high temperature.

So the two experiments aim at determining the replication mechanism.

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2 years ago

According to the fossil record found in these sedimentary layers, what conclusion can be drawn about the movement of life to lan

timofeeve [1]

The correct answer is: B) As land plants became more complex, animal life did as well.

This is because land could not be colonized by other organisms such as animals until land plants became established-there was nothing for animals to feed on.

So, plants were one of the earliest organisms to leave the water and colonize land.

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2 years ago

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Which of the following is a decomposer? A. Grasshopper B. Sunlight C. Tadpole or D. Earthworm

romanna [79]

Earthworms are decomposers

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3 years ago

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HELP!! DNA was isolated from water samples taken from six different sites. This gel

VladimirAG [237]

After running DNA in a gel, bands of different sizes and species might appear. Scientists know silver carp are at North Shore site 1 because one of the bands in lane 1 matches a band in the positive control (Option C).

When DNA was isolated and run in a gel, many bands migrated to different points.

These bands were the different-sized fragments of DNA samples from different species from the six sites.

Researchers wanted to figure out where the silver carp is.

To do it, they needed to identify the bands on the gel that belonged to the silver carp DNA, so they included negative and positive controls to make comparisons.

<h3>Positive and negative Controls</h3>

Negative and positive controls guarantee the interpretations of the results.

The positive control shows the band sizes that belong to the silver carp DNA.

Any band in the sampling sites that matches one of the positive control bands indicates that the species is present at that site.

The negative control is the opposite. It is the absence of the species' DNA.

<h3>Results interpretation</h3>

As we can see, there are four sites where the bands match one of the bands of the positive control. These are,

North shore site 1
Chicago site 1
Calumet site 1
Calumet site 2

This means that at these four sites, the silver carp is present.

So scientists know silver carp are at North Shore site 1 because one of the bands in lane 1 matches a band in the positive control (Option C).

By looking at the lane of the North Shore site 1, we can also see another band (Thinner and grey). But this band does not match either of the positive control bands. This result suggests that the grey band belongs to another species' DNA.

You can learn more about gel electrophoresis at

brainly.com/question/9437877

brainly.com/question/895793

4 0

2 years ago