Answer:
Following Statements are true.
1. Cells receive molecular signals that communicate their position in relation to other cells.
3. Differential gene expression affects the developmental process in animals.
4. Positional information controls pattern formation.
6. Homeotic genes code for transcription factors that control the development of segment-specific body parts.
Explanation:
The formation of an eukaryotic organisms's spatial organization which includes organ formation and tissue arrangement is called as Pattern formation.
Molecular signals are received by cell. This phenomenon collectively refereed as positional information. Through this phenomenon cells are informed about their locomotion with respect to body axes and other cells. Regulation of pattern formation is controlled by Positional information.
When body axes is established a gene called homeotic gene start working as regulatory genes. This gene identify specific body segment in an organism which results in the formation of segment-specific body structures in the correct locations on the body.
If the conclusions do not support their hypothesis they would start the experiment all over again and see what they did wrong. <span />
Tretinoin is a naturally occurring metabolite of retinol in the retinoid class, including natural and synthetic analogues. It is the acid form of vitamin AIt acts on cell growth and differentiation. Its main use is the treatment against acne thanks to its keratolytic and anti-inflammatory properties. Tretinoin is also used in the treatment of acute myeloid leukaemia type 3 (AML 3).
SIDE EFFECTS:
Among the expected effects, side effects may occur. Signs of an allergic reaction include: hives, difficulty breathing, swelling of the face, lips, tongue or throat;
It should be known that tretinoin can make you more sensitive to the sun, so use sunscreen every day, and wear protective clothing outdoors.
Cholesterol and triglycerides should be done before and during treatment because this drug could increase their values
Some patient with leukaemia treated by tretinoin has suffered from The syndrome of retinoic acid which is characterized by fever, dyspnea, acute respiratory distress...
