Climatic variations and Human activities , i don’t know the third reason ..
The term ''tissue'' refers to a group of similar cells. Being a combination of equal cells, a tissue has the same function in any part of the body.
The four types of tissues are:
. The epithelial tissue
. The connective tissue
. Muscle tissue
. The nervous tissue
. The epithelial tissue serves as a cover, among these are the skin and the lining of several ducts inside the body. It is divided into two general classifications: Simple Epithelium and Stratified Epithelium.
. The connective tissue supports and joins other tissues such as bone, blood and lymphatic as well as adipose tissue and reticular tissue.
. Muscle tissue consists of striated or voluntary muscles that move the skeleton and smooth muscle, such as the one that surrounds the stomach. It is divided into three types: Skeletal Muscle Tissue, Cardiac Muscle Tissue and Smooth Muscle Tissue.
. Nervous tissue is formed by nerve cells or neurons and serves to carry messages to and from various parts of the body. This tissue is present mostly in the brains and spinal cord. It has two types of tissue: The Nerve Cell and the Neuroglia.
Quantity of Heat = Mass x Heat Capacity x Temperature Change
This may be shortened to:
q = mcΔT
where:
q = Quantity of heat in Joules (J) m = Mass of the substance in grams (g) c = Specific Heat Capacity (Jg-1) ΔT = Change in Temperature (Δ = This symbol is "delta", which is Greek for "change")
Enzymes help speed up chemical reactions in the human body. They bind to molecules and alter them in specific ways. They are essential for respiration, digesting food, muscle and nerve function, among thousands of other roles.
Answer is D:60% fat
Hope this helps