Why would a mutation that involves a centromere have a greater impact than a mutation that occurs elsewhere on a chromosome?

imagine a cell-surface receptor protein is being newly synthesized. How can it get into the membrane that it will ultimately be

motikmotik

Answer:

the steps for a new receptor synthesis:

Explanation:

Do not forget the steps vary from an eukarityc cell to prokarityc one.

IN AN EUKARYOTIC CELL:

1- Transcription: in the nucleus, mRNA is synthesized from the DNA sequence that codifies the protein. Exons are spliced if needed by spliceosomes.

2- From nucleus into cytoplasm: mRNA goes through nuclear membrane into the cytoplasm were ribosomes, substrates for protein synthesis and other organelles are.

3- Ribosomes recognize a signal in mRNA and start reading the genetic code, three consecutive nucleotides at a time and adjust the correspondent tRNAs (tRNAs carry the aminoacids)

4- Peptide bonds are formed between consecutives aminoacids, and a polypeptide is build up according to the mRNA sequence.

5- (The mRNA has a signal that is recognized by the rough endoplasmic reticulum) The peptide goes into this reticulum (RER) and then into Golgi apparatus. (more chemical modifications are made if needed). By this moment the protein has an inserted portion in a lipid membrane.

6- The protein is transported in a vessel that finally fusions with cytoplasmic membrane and the receptor is in destiny. Hydrophobic aminoacid sequences are inserted in membrane.

IN A PROKARYTIC CELL:

1- Transcription (no splicing is needed, there are not exons)

2- There are not nucleus and cytoplasm divided (no transport)

3- Ribosomes recognize a signal in mRNA and start reading the genetic code, three consecutive nucleotides at a time and adjust the correspondent tRNAs (tRNAs carry the aminoacids)

4- Peptide bonds are formed between consecutives aminoacids, and a polypeptide is build up according to the mRNA sequence.

5- The mRNA has a signal that is guides the growing protein to cellular membrane. Hydrophobic aminoacid sequences are inserted in membrane.

8 0

2 years ago

The cells of plants and animals are similar, except for a few different structures. Which structures are only found in plant cel

Leviafan [203]

Answer:

large central vacuole

cell wall

Explanation:

Let me clear some things up for you. There are two types of cells - Prokaryotes and Eukaryotes. The principle difference between these types of cells are the structure of their genome. In case of prokaryotes, the genomic matter do not have a defined structure, it just kind of floats around in the protoplasm. But in the eukaryotes, the genome is more structured, have all kinds of proteins associated with them, and is surrounded by a two layered sack called the nuclear membrane. Both plant and animal cells have these feature of structured nucleus, therefore, they are both eukaryotes.

Now for the difference between plant and animal cells. the features you mentioned are unique about plant cells, but do not rule them out from being eukaryotes, as the 'true' structure of the nucleus is still there. Cell walls are necessary for the plant cells because plants do not posses an endoskeleton like most of the animals do. The cell wall makes the whole plant rigid so they don't fall apart or appear like a blob. Chloroplast is where photosynthesis happens, so it should most definitely be in a plant cell. Animals don't do photosynthesis so they don't have chloroplasts. Vacuoles are also present in animal cells, but they are much smaller, greater in number, and are known as lysosomes. Functionally they are virtually the same.

7 0

1 year ago

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What could happen to the environment if there were no environmental scientists to monitor it?

Blizzard [7]

Hello there,

Your correct answer would be: "<span>great increase in air, land and water pollution; no one to ensure proper disposal of toxic wastes; increased destruction of habitats; increase in species extinction"

Hope this helps!

~HotTwizzlers</span>

8 0

3 years ago

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Which letter on the image represents the MID-OCEAN RIDGE?

blsea [12.9K]

Answer:

A is the image that represents the Mid Ocean ridge

3 0

2 years ago

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Molodets [167]

Answer:

There are many ways.

Explanation:

Humans have a combined respiratory and circulatory system, whereas insects do not. In humans, the air is brought in through the mouth/nose, through the windpipe, and into the lungs, the oxygen is absorbed into the bloodstream where it can be transported to muscles and organs. However, insects take in air through tiny holes in their thorax and abdomen. These are called spiracles. The oxygen is stored in many dorsal air sacs to be used. Then carbon dioxide is expelled through the spiracles.

4 0

1 year ago