Answer:
B. The <em>pituitary</em> gland
Explanation:
Can't be the ovaries, they're down by the hips!
Can't be adrenal glands, they're on top of the kidneys!
Can't be the thyroid, that's low on the front of the neck or something like that!
It's B, the pituitary; it's on the base of the brain.
Have a great day!
The first line of defence (or outside defence system) includes physical and chemical barriers that are always ready and prepared to defend the body from infection. These include your skin, tears, mucus, cilia, stomach acid, urine flow, 'friendly' bacteria and white blood cells called neutrophils.
Members of phylum Porifera are commonly known as spongs. They are generally marine and mostly asymmetrical animals. These are primitive multicellular animals and have cellular level of organization (lacks tissues). These Organisms (belonging to phylum Porifera) lacks most of the structures that are present in multicellular organisms like digestive system, respiratory system, Brain etc
Body of Spongs are made up of spicules or spongin fibers and these organism contain a water canal system which helps them in digestion, reproduction and catching their food in marine habitat.
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.
