Question

SHORT ANSWER. Use as few words as possible to answer the following questions. List three elements often found in such low concentration in soil that they limit normal plant growth and are major components of commercial fertilizers. Identify the process that occurred in bilaterally symmetrical animals that resulted in the concentration of sense organs at one end of the body. Some seeds, (e.g. popcorn) burst open when exposed to high heat. Why? Identify the tube formed from involution of cells during gastrulation in an animal.

Answer 1

Bold font is the short answer if you prefer that

a) the nature is a marvel. all the varieties of plants birds animals etc. the all of the organisms are made of elements or atoms of carbon hydrogen oxygen nitrogen phosperous potasium etc. in different ratios and combination. and hence these along with some metal ions like magnesium is the essential atoms for an organism formation. lak of these elements will lead to deformities.

among this Nitogen potassium and phosphorous is the key molecules which can influence the growth of plants and animals and is the key components in commercial fertilizers.

Nitrogen- for nucleic acid formation

phosphorous- energy molecules and nucleic acid formation

potassium- for sodium potasium ion pump for signalling

b) cephalisation is the process which lead to the process of bilateral symerty in the organism. the cephalisation is the process of formation of head and associated pats. this process can divide the body in atleast two way head and trunk. platyhelminthus or flatworms are the first phyla to have differentated heads.

c) Most of the interaction that hold things are made by bond formation. these are highly stable structures with least energy conformaation for stability. every organism is held by such innumerous bondings between the atoms or molecules to keep the organism intact. sunlighy is an ionising radiation meaning ir has energy in the form of heat as IR radiations. when this energy hits the surface of some object if the bond energy is less that that of the supplied energy , will lead to the bond cleaving and deformationof structure.

corn is a seed with a outer hard later and inner soft layer. the heat will make the inner soft part to expand along with breaking the bonds of outer part leaving it to burst open

d) Gastrulation is the process of formation of gastrula from blastula. the three primaly germ layer will form as a result of gastulation. involution is the rolling and inward movement of the cells. the cells of the endoderm will involute to the ecroderm leading to the formationnof digestive tract. this makes the body into a tube ina tube structure with a hollow cavity inmiddle and from the 3 primary germ layes the f=different organs will for leading to organsm formation.