Ask questions and get helpful answers.

The lactose (lac) operon in E. coli is an example of a gene that is repressed when lactose is not available in a cell. In 3-5 sentences, explain what this means, using correct terminology.

please someone help me get the correct response. im almost failing biology and this question is the only one im haveing an issue with.

  1. 👍
  2. 👎
  3. 👁
  4. ℹ️
  5. 🚩

15 answers

  1. Short essay questions and answers...

    15. Compare and contrast the traits of viruses and bacteria. Is a virus considered a living thing? Explain your answer in 3–5 sentences.
    Bacteria are living organisms, viruses however are not. Viruses only grow and reproduce inside of the host cells they infect inside the body. When found outside of these living cells, viruses are not as effective, if at all. Their existence requires the taking over of the biochemical activities of a living cell. Bacteria, on the other hand, are living organisms that consist of single cell that can generate energy, make its own food, move, and reproduce. Bacteria have a mind of their own you could say.

    16. Hemophilia is a hereditary bleeding disorder that primarily affects males. In 3–5 sentences, summarize why this condition typically affects males more than females.
    Most people who have hemophilia are born with it. It almost always is inherited from a parent to a child. The hemophilia disorder inherits and transfers the X chromosome, or the male, more often than the female chromosome. Hemophilia is not found in many females because the disorder does not inherit and transfer the Y chromosome, or the female, often.

    17. The lactose (lac) operon in E. coli is an example of a gene that is repressed when lactose is not available in a cell. In 3-5 sentences, explain what this means, using correct terminology.
    The lac operon of E. coli contains genes involved in lactose metabolism. This is found only when lactose is present and glucose is absent in the metabolism. Two regulators turn the operon "on" and "off" in response to lactose and glucose levels. The lac repressor acts as a lactose sensor. It normally blocks transcription of the operon, but stops acting as a repressor when lactose is present. The lac repressor senses lactose indirectly through its isomer lactose. Catabolite activator protein acts as a glucose sensor, it activates the data of the operon, but only when glucose levels are low. Catabolie activator protein senses glucose indirectly, through hunger factor molecule location.

    18. Homozygous tall pea plants look the same as heterozygous tall pea plants. Formulate a pollination experiment to identify whether a tall pea plant is homozygous or heterozygous. Explain your answer in 3-5 sentences.
    Experiment - I would plant each of the plants in the same area/field and watch them grow together. As they grow, I would carefully monitor their growth and crossbreeds. When they have finished growing and are at full length, I would take tests from each of the pea plants and its seeds.

    19. In 3–5 sentences, explain how genetic modification helps provide food for a growing population.
    Genetic modification allows for foods to grow larger and more of it in a shorter amount of time. This allows growing populations to provide the necessary amount of food. Using modification, you can also reduce the need for pesticides and other harsh chemicals that might damage the foods original properties.

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  2. The lac operon of E. coli contains genes involved in lactose metabolism. It's expressed only when lactose is present and glucose is absent. Two regulators turn the operon "on" and "off" in response to lactose and glucose levels: the lac repressor and catabolite activator protein (CAP). The lac repressor acts as a lactose sensor. It normally blocks transcription of the operon, but stops acting as a repressor when lactose is present. The lac repressor senses lactose indirectly, through its isomer allolactose. Catabolite activator protein (CAP) acts as a glucose sensor. It activates transcription of the operon, but only when glucose levels are low. CAP senses glucose indirectly, through the "hunger signal" molecule camp.

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  3. bro i understand i literally have had no troubles besides this question, just cant find any info about it

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  4. Here are the answers. However, they are not in order so find the right answer below that matches the question...

    The sequence could code for the wrong amino acid during translation.
    DNA unzips between the base pairs.
    The human body uses 20 amino acids to form all types of proteins.
    Cystic fibrosis is caused by a deletion of one codon in the DNA molecule.
    Precise traits can be chosen to produce viable organisms more quickly.
    fur with black hairs
    25%
    there is not enough information to know whether a mutation would be harmful
    Punnett squares are used to predict all possible allele combinations and their frequencies in offspring.
    yellow
    viral DNA or RNA copied by a host cell
    A provirus is viral DNA incorporated into the host cell’s DNA.
    It possesses a viral genome that mutates very quickly.
    It copies the information for reproduction from RNA back into DNA.

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  5. cause some of us need to not be a disappointment to our family in certain areas

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  6. Alright, i know this isn't a direct answer but this video gave me the info. "khanacademy.org/science/biology/gene-regulation/gene-regulation-in-bacteria/v/lac-operon?modal=1"

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  7. @Anonymous, if you're on here, then so are you.

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  8. @Anonymous because we can

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  9. I actually recommend the khan academy video "yup" sent. It helped a lot and I was able to get the answer on my own pretty easily.

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  10. im also having difficulty with this lol

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  11. tysm No Name !!
    all correct !!

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  12. thank you

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  13. Thx No Name!
    But I still have one question...
    Does anyone know the answer to this question:
    Code this DNA Strand into mRNA: 3’ ATG CAG TGA ATT 5
    I can't figure it out att all ;-;

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  14. you guys need stop your going to get banded from here if you keep saying stuff like that because they are trying to fix the matter but people like you are always in the way of things

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  15. Why are you all cheating?

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩

Answer this Question

Related Questions

Still need help?

You can ask a new question or browse existing questions.