1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
dusya [7]
3 years ago
10

One difference between human cheek cells and onion cells is: 1. the presence of cytoplasm 2. the absence of a nucleus in the pla

nt cells 3. the absence of a cell wall in human cells 4.none of the above
Biology
1 answer:
AysviL [449]3 years ago
6 0

Answer:

3. the absence of a cell wall in human cells

Explanation:

Animal cells do not have cell walls. Cell membranes separate the cytoplasm of the animal cells from the surroundings and maintain their interior. Plant cells have cellulosic cell walls. A cell wall surrounds the cell membrane of a plant cell. Cell walls serve to provide structural support and protect plant cells from pathogens. Cell walls also help keep excess water out of cells so they do not burst. Therefore, human cheek cells would not have cell walls while the onion cells would have cell walls made up of cellulose.

You might be interested in
Define<br> nitrogen fixation:<br> logistic growth rate: <br> plz:)
V125BC [204]

They contain symbiotic bacteria called rhizobia within nodules in their root systems, producing nitrogen compounds that help the plant to grow and compete with other plants. When the plant dies, the fixed nitrogen is released, making it available to other plants; this helps to fertilize the soil.

8 0
3 years ago
Read 2 more answers
From a chemical view, how is an amino acid is being recognized by its specific aminoacyl tRNA synthetase?
hammer [34]

During translation, rRNA and tRNA read mRNA in 5´ to 3´ direction. According to the codons being readen, tRNA transfers the correct amino acids to build the polypeptide chain. A codon is a short sequence of three nucleotides that store the genetic information for the aminoacids´ assembly.

Each tRNA has two important sites. One of them that couples with the codon of the mRNA molecule, named anticodon. The other site couples with an amino acid through the action of the aminoacyl-tRNA synthase enzyme. The whole complex, amino acid + enzyme + tRNA is named aminoacyl-tRNA.        

Each tRNA is recognized by a specific aminoacyl-tRNA synthase enzyme. The enzyme is also capable of recognizing a specific amino acid. Let us say, for instance, that <em>tRNA is specific for phenylalanine.</em> The molecule is attached to the <em>enzyme that is specific for that tRNA(Phe)</em>. Then, when the enzyme and tRNA(Phe) are together, they get to <em>find phenylalanine</em>. The <em>enzyme links the aminoacid to the RNA</em>. Once the whole complex is formed, the <em>tRNA gets to pair its anticodon with the mRNA codon</em>. This is,

  1. Recognition of enzyme and the specific tRNA(aa) ⇒ aa being aminoacid
  2. Recognition of enzyme and the specific aminoacid
  3. Linkage of the aminoacid to RNA by the enzyme action
  4. Pairing of tRNA anticodon to mRNA codon.

Considering that there are twenty amino acids available, there are also twenty complexes of aminoacyl-tRNA, one for each amino acid. Each of the mRNA codons represents one of the 20 amino acids used to build the protein. Each amino acid can be codified by more than one codon. Of the total 64 codons, 61 codify amino acids, and one is a start codon. The left three codons are stopping translation points.

tRNA decodes genetic information from the nucleotidic sequence in the mRNA molecule and allows amino acids to align composing the new protein.  

Once the new peptidic link joins, placing together the new amino acid to the growing peptidic chain, the binding between the amino acid and the tRNA molecule breaks. The tRNA is now free to join another amino acid and repeat the cycle.

In conclusion, a specific aminoacyl-tRNA synthase enzyme recognizes a tRNA, which is also specific for a certain amino acid. When together, the enzyme recognizes the amino acid and links it to the RNA. The whole complex is known as aminoacyl-tRNA. Once the tRNA is joined to its amino acid, it gets to pair a codon of mRNA to add that amino acid to the new synthesizing protein.

6 0
3 years ago
A man travelling in a train threw an empty packet of food on the platfrom. Do you think this is a proper waste disposal method?
Anit [1.1K]

Answer:

No it is not a proper waste disposal method

Explanation:

A man travelling in a train and throwing an empty packet off food on the platform and not inside the waste basket provided is definitely not a proper waste disposal. the best waste disposal method he would have used was throwing the waste in a waste bin

waste water management is the process of managing waste water emanating from homes or industries and controlling the negative impact this waste water would have on the environment. and one way to do that  is the proper treatment of the water which entails removing contaminants from the waste water and converting the waste water into a useful effluent that can be used again ,

4 0
4 years ago
These characteristics, or adaptations, are
kkurt [141]

A) ability to learn or acquire the new traits

Explanation:

It's the process that species go through in order to become accustomed to an environment.

4 0
3 years ago
In the past, an irregular heart rhythm was treated by using a drug to help regulate the beat. There is a treatment that can also
scZoUnD [109]

Answer:

I believe this is a pacemaker. It controls the heart when it starts to fail.

Explanation:

8 0
3 years ago
Other questions:
  • <img src="https://tex.z-dn.net/?f=hhhhhhhhhheeeeeeeeeeeeelllppppppppp%20%3A%28" id="TexFormula1" title="hhhhhhhhhheeeeeeeeeeeeel
    9·1 answer
  • In angiosperms, pollen grains develop in the ________ and land on the ________.
    7·1 answer
  • George has attached ear lobes. Barbara has free ear lobes, but she is heterozygous for this trait. What are the chances of their
    8·1 answer
  • What is the atomic number of this element?<br><br> A) 15<br> B) 17<br> C) 35<br> D) 52
    15·2 answers
  • Jesse has recently started using methamphetamines. Which of the following is he risking by taking this drug? Stroke, Blood press
    11·1 answer
  • Which action is NOT a way to test a hypothesis? a. Analyze results b. Design an experiment c. Make a model d. Gather and evaluat
    7·2 answers
  • Estrogen, progesterone, LH, and FSH are chemicals produced by the body that are important to a woman’s fertility. What organ sys
    6·1 answer
  • I NEED HELP WORTH 38<br><br> With a justification please
    8·1 answer
  • Karen bought a birdbath made of concrete. The salesman suggested that she seal
    7·1 answer
  • Diego is conducting an experiment to investigate how temperature affects chemical change. He has three pieces of cheese that he
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!