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defon
3 years ago
7

Wild diploid wheat has seven chromosomes in its pollen. Discuss the major events that had to occur for tetraploid pasta wheat to

have evolved. Describe the genome and fertility of pasta wheat (number and kinds of chromosomes).
Biology
1 answer:
lianna [129]3 years ago
5 0

Answer:

Tetraploid wheat evolved by allopolyploidization and subsequent diploid-like behavior due to cytological diploidization

Explanation:

Durum wheat (<em>Triticum durum</em>) or pasta wheat, is a tetraploid wheat species that has 28 chromosomes, i.e., seven pairs in each genome (2n = 4x = 28). Durum wheat was domesticated from wild emmer wheat, which originated by hybridization of two diploid wheat species with 14 chromosomes: <em>Triticum monococcum</em> (genome AA) and one wild progenitor (genome BB). <em>Triticum durum </em>is a typical example of evolution by hybridization and polyploidization, where the resultant tetraploid species has two complete sets of chromosomes. Allopolyploidization is one of the most common types of plant speciation. During meiosis, 28 chromosomes form 14 homologous chromosome pairs, because homologous chromosomes have developed 'restriction of pairing' (i.e., cytological diploidization). The restriction of pairing to fully homologous chromosomes ensures a correct meiotic behavior, which otherwise would be altered due to the high level of homology that still exists among chromosomes from different wheat progenitors.

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Which of these statements best describes how a vaccine can protect a person from an infectious virus?
leonid [27]

The correct answer is A. A small dose of the weakened virus is given to the patient so that antibodies can form.

Explanation:

The purpose of a vaccine is to stimulate the immune system of individuals and allow this to create antibodies that can appropriately respond to the virus. This is achieved by creating or producing a weakened or modified version of the virus, then giving this virus to the patient in a low dose that does not make the patient sick but allows his body to produce specific antibodies that can recognize and attack the virus appropriately. In this way, if the patient is in contact with the regular version of the virus its body will generate an appropriate immune response and stop the virus from triggering infection or make the patient sick. In this context, the statement that best describes how a vaccine works is "A small dose of the weakened virus is given to the patient so that antibodies can form".-

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4 years ago
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givi [52]
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7 0
4 years ago
In the 19th century, Gregor Mendel performed a series of experiments on pea plants that led to the establishment of the field of
guajiro [1.7K]

This is a very easy paragraph analysis question. The answer is c. "Over time, scientific knowledge is reevaluated and extended through new scientific research." The reason why the answer is C., is because the chronological order of the study of genetics is as follows:

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Overall, we see a trend of scientists publishing results based on what scientists did before.

8 0
3 years ago
Which qualities describe the entire open-ocean zone? Check all that apply. few nutrients
uysha [10]

<u>Answer:</u>

- few nutrients

- high pressure

- low temperatures

<u>Explanation:</u>

1. Few nutrients:  open-ocean zone is located way far from the land, which is the main source of the essential nutrients.

2. High pressure: pressure increases by 1 atmosphere for every 10 meters increase in depth.

3. Ample sunlight: a large fraction of the sunlight is reflected back to the atmosphere from the sea surface.

4. Varying salinity: below the thermocline, the water is isolated from the atmosphere so the salinity remains stable over the year.

5. Low temperatures:  the temperature of open-ocean zone ranges from a low of -2°C to an average of 17°C.

8 0
3 years ago
Read 2 more answers
Select all that apply.
solong [7]

Answer:

They are all carbohydrates.

Explanation:

Homo polysaccharides include starch, glycogen, and cellulose (same type of sugar-all made of glucose).

1- Amylose and Amyloprotein are the components of starch. Amylose is a branched chain with alpha 1–4 and alpha 1–6 at the branch point, whereas Amylopectin is a linear chain with alpha 1–4 and alpha 1–6 at the branch point.

2- Glycogen is created by forming a branched chain from glucose at alpha 1–6. It has a lot of branches.

3- Cellulose is a linear chain of glucose molecules with beta bonds.

Starch and glycogen serve as short-term energy stores in plants and animals, cellulose found in plant cell wall only.

7 0
3 years ago
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