The lac repressor protein is bound to the operator region of the lac operon when there is no lactose in the medium. When introduced in lactose, it binds to an allosteric site on the repressor causing its to change conformation and release from the operator. This allows the polymerase that is bound to the promoter region to proceed transcription of the lac operon genes (LacZ, Lac A, and Lac Y). Translation of these genes forms enzymes that enable the organism to break down lactose for energy.
Answer:
Microtubules have shapes like a spindle and are arranged to form centrosome and a cluster of such microtubules form centriole.
Explanation:
Microtubules are seen in eukaryotic cells to give shape and structure to the cells and they form part of the cytoskeleton. They are known to grow long and are dynamic. Centrosomes are known to be main microtubule that are found in animal cells. They are organelles that are made from the arrangement of clusters of microtubules. The centrioles are organized microtubules that actually help to serve as skeletal system of the cell. These centrioles help to determine the locations of the nucleus.
Answer: His genes contain a mutation that prevents red blood cells from proper functioning.
Explanation:
Hereditary anaemia is a type of disorder that are genetically transmitted to the offsprings by the parents . These type of anaemia are inherited from the parent including sickle cell anaemia.
The offsprings inherent Gene mutation that cause abnormalitiies. They inherit abnormal haemoglobin that can reduce the life span of red blood cells thereby affecting their proper functioning of carrying oxygen in the blood, leading to anaemia.
The process of DNA replication occurs just before S phase. In the interphase, the cell has growth and replication of DNA is getting made. In the G1 phase, there is the growth, (G1-checkpoint - cell size, growth, environment shows cell is ready to start replicating DNA. S phase- DNA is replicated.
