Science: BIOLOGY

• It produces bile,which helps in the digestion of fat in the small intestine


  Liver
• Releases digestive enzymes to complete the process of chemical digestion,it also regulates blood sugar by producing insulin


  Pancreas
• Stores bile from the liver,releases it into the small intestine


  Gallbladder
• Accepts what small intestines don't absorb


  Large intestine
• Breakdown and absorb nutrients from food


  Small intestine
• J-shaped muscular bag that stores the food you eat, breaks it down into tiny pieces


  Stomach
• Moves food from the throat to the stomach using muscle movement called peristalsis


  Esophagus
• Mixes food with saliva


  Tongue
• The passage of chewed/crushed food from the mouth through the esophagus


  Pharynx
• Short term storage which holds feces before it is expelled


  Rectum
• The external opening of the rectum


  Anus
• Plays crucial role in the process of chewing and breaking down foods


  Teeth
• Play a important role in the production of saliva


  Salivary glands
• A flap-like structure at the back of the throat that closes over the trachea preventing food from entering it


  Epiglottis
• Acts as a gateway between the stomach and the small intestine


  Pyloric sphincter
• Traits


  Characteristics inherited from parents
• Scientists can calculate probabilities of having a specific trait or getting a genetic disease according to information from the parents and family history
• Gregor Mendel


  Austrian monk and biologist who discovered the principles that rule heredity by breeding pea plants
• Mendel's experiment with pea plants

  1. Crossed purebred yellow-seeded plant with purebred green-seeded plant

  2. Got only yellow seeds in first generation

  3. Let the yellow-seeded hybrid plants self-fertilize

  4. Got both yellow and green seeds in second generation
• Dominant trait


  Trait that is expressed in all the new seeds
• Recessive trait


  Trait that is hidden by the dominant trait
• Alleles


  Factors that determine a trait, one from the mother and one from the father
• Homozygous


  When both alleles are identical
• Heterozygous


  When the two alleles are different
• Genotype


  Combination of alleles
• Phenotype


  Result of the genotype, being yellow or green
• Punnett square


  Diagram used to visualize how alleles are distributed amongst descendants
• There are many other ways in which some characteristics are inherited besides the principles discovered by Mendel
• Genes


  Parts of your cells that determine traits such as hair color, shape of face, color of skin, etc.
• In the past, no one knew what genes were
• In the 20th century, scientists figured out that genes are actually made of DNA
• Genes

  Come in pairs, you inherit half from your mother and half from your father
• How a human develops

  DNA tells the single cell to divide into two cells, then four, then eight, until a whole body is formed
• Genetics


  The study of genes and heredity, how genes and traits are passed down from one generation to the next
• The science of genetics began

  1800s
• Gregor Mendel


  Father of genetics, figured out how traits are inherited by studying peas
• Mendel's laws of heredity

  • The law of dominance
  • The law of segregation
  • The law of independent assortment
• Law of dominance

  An organism with alternate forms of a gene will express the form that is dominant
• Law of segregation


  Each individual has a pair of alleles, a copy for a particular trait, and each parent passes an allele at random to their offspring
• Law of independent assortment


  The alleles of two or more different genes get sorted into gametes independently of one another