Answer:
The lactose present prevents the production of lactase
Explanation:
This question is describing a set of genes in bacteria called LAC OPERON. Lac operon controls the production of lactase, which is the enzyme that digests lactose. However, this gene can be regulated at the transcription level i.e caused to be transcribed or not depending on certain factors.
According to the question, lac operon, which regulates the production of enzymes will be transcribed and subsequently translated i.e. turned on when there is a substrate (lactose) that the produced enzyme will work on. However, when there is no need of the lactase enzyme or there is absence of lactose (substrate), the lac operon gene is turned off.
Note that, the statement that "The presence of lactose prevents the production of lactase" is not correct.
Answer: Point source
Explanation:
An exotoxin is a toxic substance secreted by bacteria. The botulism exotoxin is the exotoxin secretes by bacterial strain named as Clostridium botulinum.
Point source outbreak is a condition in which people are exposed to the same source of infection from a pathogen. This may occur due to the consumption of a single meal which is being infected by the pathogen. This may lead to incidences of food poisoning, disease and even mass death.
Answer:
NO! They require a ton of attention, a large cage, and experience with birds. Parakeets are often marked as starter pets, but no, they are not.
First, they need a 3 feet long cage with 5+ toys that need to be changed each month. And they need natural perches, not the cheap wooden dowels, they will get feet problems. Most people don't do this, having a bored pet.
Second, parakeets will chew anything given/available to them, and a lot of things can be toxic to them, which can lead to the death of your pet.
Third, parakeets are messy and noisy. They poop a LOT and love to toss seeds around their cage. They also need millet and a calcium chew, which are also messy.
They also will want a friend, they are flock animals in the wild so 3-4 birds is a good number, but getting more birds means getting a large cage. The pet store will tell you it's fine, but it is not. ALWAYS SEEK HELP FROM A BIRD BREEDER.
Lastly, they need a bird proofed room to fly around in. No matter how large your cage is, they still need some out-of cage time.
Try a dove or pigeon instead, they are listen the #1 easiest and cheapest to care for pet bird.
A plant cuticle is a protecting film covering the epiderms of leaves, young shoots and other other aerial plant organs with out periderm. It consists of lipid and hydrocarbon polymers impregnated with was and is synthesized exclusively by the epidermal cells.