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
True [87]
3 years ago
13

The lactose (lac) operon in E. coli is an example of a repressed gene when lactose is not available in a cell. In 3-5 sentences

Biology
1 answer:
irakobra [83]3 years ago
4 0

Answer:

Please find the detailed explanation of this statement below

Explanation:

Firstly, a repressed gene is a gene whose expression has been inhibited or repressed. The lac operon in E.coli bacteria is a regulatory unit containing structural genes, a single promoter and operator regions. The promoter is the region where the transcription enzyme (RNA polymerase) binds to in order to transcribe the genes in the lac operon. The structural genes in the lac operon can only be expressed in the presence of lactose sugar.

However, in the absence of lactose, LAC REPRESSOR, which is a transcription factor (protein), prevents the binding of RNA polymerase to the PROMOTER region by binding to the OPERATOR region of the lac operon. This inhibits the expression of the lactose genes in the operon.

Note that, the structural genes in the lac operon (lacZ, lacY, lacA) code for proteins that help break down lactose sugar for energy in the E.coli bacteria. Therefore, a bacteria cell with a repressed lac operon will be unable to degrade lactose sugar.

You might be interested in
Which of the following best describes how enzymes effect chemical reactions
lyudmila [28]

Answer:

1 they speed up to change the rate

Explanation:

please mark me as brainliest answer

6 0
2 years ago
Which statement about abiotic changes to an ecosystem is true ?
Lena [83]
The very first one is the answer-

Abiotic changes have the ability to dictate biotic ones. This can be caused by humans.
For example: an abiotic thing can be an element like water. If the water in a lake gets poisoned by chemical compounds, this is an abiotic change. However, since the lake is now poisoned it’ll likely harm or even kill fish, bacteria, algae, and any other wildlife living within the lake. It doesn’t stop there though, without the lake surrounding animals won’t have clean water to drink, they can now die from either the poisoning, dehydration, or starvation if they lived off of the aquatic life from the lake.
4 0
2 years ago
In simple terms, what is fracking?
mars1129 [50]

Answer: Fracking is drilling into earth and directing a mixture of water, sand and chemicals at a rock layer to release gas inside.

5 0
2 years ago
Read 2 more answers
in sexual reproduction an offspring is produced with genes from both parents when the offspring has a new genetic variation that
cluponka [151]

Explanation:

Mutations introduce novel variety in a population.

During the process of cell division, spontaneous changes within the genome can arise. These mutations are errors occur when copies of the DNA within the cell are made; mutations may range from small changes called single nucleotide polymorphisms, to large scale deletions, and additions which span multiple genes. There are two types:

  • somatic: these only occur within certain cells, and arise from environmental factors such as UV light
  • hereditary: occur within germ cells of the parent and later the fertilized egg which forms a zygote; these are present within all cells of the new organism.

Further Explanation:

During reproduction other events, such as crossing over during  meiosis, mutations lead to increases in genetic variation. This variation refers to the genetic characteristics present within a species. Mutations may be either beneficial or deleterious; they are maintained within cells, as they form new traits called alleles. Beneficial mutations may confer traits that increase the fitness of a species, along with ensuring survival by conferring a protective advantage- these phenotypic differences between organisms are called adaptations.

Sequences of DNA make up genes which can have different forms called alleles. DNA, which makes up the genotype, is transcribed into mRNA and later translated into amino acids which are linked together by rRNA to form proteins which make up the phenotype of an organism.Mutations in DNA sequences affect the corresponding mRNA and thus the protein encoded.

Learn more about mutations at brainly.com/question/4602376

Learn more about DNA and RNA at brainly.com/question/2416343?source=aid8411316

#LearnWithBrainly

3 0
3 years ago
Which two Domains have ONLY unicellular organisms?​
fgiga [73]

Answer:

The correct answer is - Archaea and Bacteria.

Explanation:

There are three different domains of life on earth; Archaea and Bacteria are two domains that are completely single-celled prokaryotic cells that lack a nucleus and other double-membrane organelles.

These both domains are very much similar and has their own difference to be categorized in two other domains. The eukarya domain on other hand has different kinds of organisms like unicellular to multicellular organisms.

4 0
2 years ago
Other questions:
  • Were are yall from how long have you been there
    6·1 answer
  • Match each of the four barriers of innate immunity with its mode of action.
    9·1 answer
  • Need help fast please!!!
    12·1 answer
  • Nina is learning about plants in school. Her teacher gives her group a stack of cards that list things that plants might need to
    14·2 answers
  • What was the significance of the Luetgert murder case of 1897? Why was this a turning point for forensic anthropology?
    5·1 answer
  • What components of the introns of nuclear genes that encode proteins in higher eukaryotes are conserved and required for the cor
    15·1 answer
  • ________________________ is without symmetry.
    13·1 answer
  • Carbohydrate layer on the plasma membrane includes all of the following except:
    10·1 answer
  • Describe the following methods of genetic engineering: gel electrophoresis,
    7·1 answer
  • What is globle warming
    11·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!