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.
Answer:
See the answer below
Explanation:
<em>Amphibians are not totally adapted to live on land because the aquatic environment is needed for several life processes such as </em><em>reproduction</em><em>, </em><em>respiration</em><em>, and sometimes, </em><em>feeding</em><em>.</em>
<u>The eggs of amphibians are without any protective shells and will suffer desiccation in the terrestrial environment. Hence, water is needed in order to protect the eggs. In addition, the male am</u>phibians shed their sperm in the water close to the female eggs.
<u>The young ones of amphibians are essentially aquatic and may not survive out of water for a long time because they only breathe gills</u> - the lung is yet to develop or poorly developed at this stage. They have to grow and develop to a certain stage in water before they can start surviving on land.
Gram-positive microorganisms have a thicker layer of peptidoglycan which traps a greater amount of the gem violet included and upon de-colorizer discharges approximately caught stains.
Gram-positive cell dividers contain a thick peptidoglycan layer with teichoic acids. Gram-negative cell dividers contain a thin peptidoglycan layer that is encompassed by a thick plasma film. Gram-positive microorganisms will recolor purple in view of their thick peptidoglycan cell divider.
