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
zvonat [6]
3 years ago
12

What are the 4 steps in the cell cycle

Biology
1 answer:
Dafna11 [192]3 years ago
4 0

The cell cycle is a four-stage process in which the cell increases in size (gap 1, or G1, stage), copies its DNA (synthesis, or S, stage), prepares to divide (gap 2, or G2, stage), and divides (mitosis, or M, stage). The stages G1, S, and G2 make up interphase, which accounts for the span between cell divisions.

You might be interested in
What is anemophroia,hydrochoria,anthropochoria and zoochoria?​
Juliette [100K]

Answer:

also known as anemophobia, is an extreme fear of wind or drafts. It is rather uncommon, and can be treated. It has many different effects on the human brain. It can cause panic attacks for those who have the fear, and can make people miss out on regular everyday activities such as going outside.

In chemistry, a hydrochloride is an acid salt resulting, or regarded as resulting, from the reaction of hydrochloric acid with an organic base. An alternative name is chlorhydrate, which comes from French. An archaic alternative name is muriate, derived from hydrochloric acid's ancient name: muriatic acid.

Meaning of zoochoria in the Polish dictionary with examples of use. Synonyms for zoochoria and translation of zoochoria to 25 languages.

Anthropochore definition is - a plant that is regularly distributed by humans whether deliberately (as crop plants) or accidentally (as weeds).

Explanation:

8 0
3 years ago
Example of FAST moving carbon.
WITCHER [35]

Answer:

The fast carbon cycle is largely the movement of carbon through life forms on Earth, or the biosphere. ... During photosynthesis, plants absorb carbon dioxide and sunlight to create fuel—glucose and other sugars—for building plant structures. This process forms the foundation of the fast (biological) carbon cycle.

\

3 0
3 years ago
Describe the probable effects on gene expression in the lac operon of each mutation: a. Mutation in the lac operator that delete
Stella [2.4K]

Answer:

a. Reduces represor binding.

b. Constitutive expression of the operon.

c. Stronger promoter if it is more similar to the consensus sequence. Weaker promoter if less similar.

Explanation:

The lac operon is an operon required for lactose transport and metabolism in enteric bacteria such as <em>Escherichia coli</em>. <u>It is regulated by glucose and lactose availability</u> and consists of the following structural genes:

  • Lac z gene: encodes the enzyme β-galactosidase, which catalyzes the hydrolysis reaction of lactose into glucose and galactose.
  • Gene lac y: encodes the protein galactoside permease involved in the transport of lactose into the bacterium.
  • Lac a gene: encodes the enzyme thiogalactoside transferase, which catalyzes the transfer of the acetyl group of acetyl coenzyme A to 6-OH of a thiogalactoside acceptor. This gene is not related to lactose metabolism.
  • Promoter: region of DNA recognized by RNA polymerase for transcription.
  • Operator: region of DNA located between the promoter and the beginning of the structural genes, which is recognized by the repressor protein Lac I.
  • Repressor gene (lac I): encodes the Lac I repressor protein, which recognizes the operator region, where it binds. It prevents the transcription of genes under the control of this promoter but stimulates the binding of RNA polymerase. When the repressor is absent (in the presence of inducer which in this case will be lactose or IPTG), RNA polymerase will begin transcription.

The lac operon is under a type of negative regulation, where genes can always be transcribed, except when the Lac I repressor protein is bound to the operon region, for which it has a high affinity. In this case, the promoter of the lac I gene is constitutive, so the Lac I protein is permanently expressed and remains bound in tetramer form to the operon region, preventing the transcription of structural genes.

Since lactose is the inducer of the operon, it is able to bind to the Lac I repressor protein and generate a conformational change that decreases its affinity for the operon region. Thus, the operon region is left free, <u>RNA polymerase can freely transcribe the structural genes and β-galactosidase can degrade lactose to glucose plus galactose</u>. <u>In the absence of lactose, the Lac I repressor protein maintains its high affinity for the operator region, preventing RNA polymerase from transcribing the structural genes</u>. In this way, the system remains closed with consequent energy savings for the bacterium.

As a final clarification, actually the true inducing molecule of the lac operon is called allolactose, an isomer of lactose obtained by a transglycosylation occasionally carried out by β-galactosidase.

a. When there is a mutation in the lac operator that deletes most of the operator, then the repressor Lac I can no longer bind and RNA polymerase will begin transcription.

b. When there is a mutation in the Lac I gene that eliminates the binding of repressor to operator, then this protein can not produce the repression so there would be a constitutive expression of the operon.

c. Since the promoter us a region of DNA recognized by RNA polymerase for transcription, if there is a mutation here it will generate a stronger promoter in the case that this part is similar to a consensus sequence (the most commonly encountered nucleotides found at a certain location). In the case that it is less similar, then it will generate a weaker promoter.

7 0
3 years ago
Which best explains why noble gases are chemically unreactive
vesna_86 [32]
<span>They have very stable outer electron shells</span>
3 0
3 years ago
What kind of mutation would occur if a sequence of DNA is changed from ATCGGCTTAACG to ATCGGCTAAACG?
Zinaida [17]

Answer:

Base substitution mutation

Explanation:

Mutation is the alteration or change that occurs to the sequence of a gene caused by a mutagen (chemicals) or spontaneously-induced. Depending on how the mutation occurs, it is of different types. The mutation shown in this question is as follows:

ATCGGCTTAACG to ATCGGCTAAACG

This type of mutation is called SUBSTITUTION MUTATION. Substitution mutation is a type of mutation that involves the replacement of one or more nucleotide base by another. In this original sequence; ATCGGCTTAACG, the eight base T was replaced by base A in the sequence, hence, it is a substitution mutation.

4 0
3 years ago
Other questions:
  • Write an example of an element using its name and symbol
    15·1 answer
  • A patient presents to the emergency department with weight loss, petechiae, and splinter hemorrhages. the patient's vital signs
    10·1 answer
  • Think of the shape of a wave. It looks like a squiggly line. We know the highest part of that line is the peak. The wavelength i
    5·2 answers
  • What evidence would you look for to determine whether a chemical change has occurred?
    12·1 answer
  • These qualities is generally true of both traditional and modern plays.
    13·2 answers
  • Pickles are cucumbers preserved in a brine solution containing dill, alum, and salt. Cucumbers shrink to a fraction of their nor
    15·1 answer
  • 6. How does the light reaction of photosynthesis affect Earth's supply of oxygen?
    10·1 answer
  • Please help :( this is a really complicated question
    7·1 answer
  • How does the extent of humans history compare to geologic history
    9·2 answers
  • What is cancer? it’s for my semester exam study guide
    15·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!