Coordination and Response in Humans

Ethylene 1.   Ethylene is a small hydrocarbon gas. 2.   It is a plant hormone which is synthesized during the ripening of fruits.3.   Ethylene is responsible for the changes in texture, softening, color, and other processes involved in ripening. 4.   Ethylene(a) Speeds up the ripening of fruits by stimulating the production of cellulose. Cellulase … Read more

5.1 Plant Hormones1.   Growth of shoots towards sunlight is called positive phototropism.2.   Growth of shoots away from sunlight is called negative phototropism.3.   In plants, hormones play an important role in growth processes such as seed germination, growth of roots and development of fruits.4.   There are many types of plant hormones, such … Read more

Question 1:Diagram 1 shows the endocrine system in human.Diagram 1(a) Name structures P and Q. [2 marks](b)(i) Name one hormone secreted by Q. [1 mark](ii) Explain the role of the hormone named in 1(b)(i) in regulating the level of glucose in the blood.(c) Table below shows the concentration of amino acid in blood plasma and … Read more

The Excretory System1.   The excretory system plays an important role in homeostasis.2.   The primary organs of the excretory system are kidneys. The human kidney1.   The kidneys filter blood and form urinewhich exits the body through the ureters, urinary bladder and urethra.2.Urine is fluid which consists of water, urea and other dissolved wastes.3.The human kidney shows three … Read more

13.1 Homeostasis in Humans 1.   The internal environment consists of interstitial fluid and blood plasma that constantly bathe the cells.2.   Homeostasis is the process of regulating the physical and chemical factors in the internal environment, so that these factors can be maintained in a dynamic equilibrium and optimum condition.  (a) The physical factors include … Read more