Humans rely on carbohydrates for much of their energy. Outline the process of digestion and
absorption of starch in the human digestive system. [4]
− Starch digestion begins in the mouth in the presence of amylase which breaks down the
starch into maltose
− There is also amylase in the small intestine, where starch continues to be broken down
− Maltose is then broken down by maltase into glucose in the small intestine
− Glucose is absorbed in the small intestine
− Villi increases the surface area of the intestinal epithelium for greater absorption
Describe the genetic and hormonal control of male sexual characteristics in a human. [3]
− Male sexual characteristics are coded for by the SRY gene which is present for male babies
during embryonic development
− The SRY gene codes for DNA binding protein TDF, leading to the expression of other genes,
therefore causing testes development
− Testosterone also triggers the formation of secondary sexual characteristics at puberty
Compare and contrast hormonal and nervous communication.[7]
− Both used for communication between cells
− Both controlled by the brain
− Both use feedback mechanisms
Hormonal Nervous
Slower Faster
Chemical Electrical
Long term Short term
Transported in blood Transported in neurons
Explain the production of antibodies in humans. [7]
− Pathogens are ingested by macrophages
− The pathogen’s antigens are displayed on the macrophage’s surface
− T lymphocytes with the specific protein receptor bind to these antigens
− T lymphocyte is activated
− It can then bind to B lymphocytes with the complementary receptor
− The B lymphocytes divide to form plasma cells and memory cells
− Plasma cells secrete antibodies to form immune response
− Memory cells are stored in case of secondary infection
Outline how proteins are digested and the products of protein digestion absorbed in humans. [4
marks]
− Proteins can be broken down by protease
absorption of starch in the human digestive system. [4]
− Starch digestion begins in the mouth in the presence of amylase which breaks down the
starch into maltose
− There is also amylase in the small intestine, where starch continues to be broken down
− Maltose is then broken down by maltase into glucose in the small intestine
− Glucose is absorbed in the small intestine
− Villi increases the surface area of the intestinal epithelium for greater absorption
Describe the genetic and hormonal control of male sexual characteristics in a human. [3]
− Male sexual characteristics are coded for by the SRY gene which is present for male babies
during embryonic development
− The SRY gene codes for DNA binding protein TDF, leading to the expression of other genes,
therefore causing testes development
− Testosterone also triggers the formation of secondary sexual characteristics at puberty
Compare and contrast hormonal and nervous communication.[7]
− Both used for communication between cells
− Both controlled by the brain
− Both use feedback mechanisms
Hormonal Nervous
Slower Faster
Chemical Electrical
Long term Short term
Transported in blood Transported in neurons
Explain the production of antibodies in humans. [7]
− Pathogens are ingested by macrophages
− The pathogen’s antigens are displayed on the macrophage’s surface
− T lymphocytes with the specific protein receptor bind to these antigens
− T lymphocyte is activated
− It can then bind to B lymphocytes with the complementary receptor
− The B lymphocytes divide to form plasma cells and memory cells
− Plasma cells secrete antibodies to form immune response
− Memory cells are stored in case of secondary infection
Outline how proteins are digested and the products of protein digestion absorbed in humans. [4
marks]
− Proteins can be broken down by protease
