GENERAL BIOLOGY

• Homeostasis


  The capability of the human body to balance itself through the proper functioning of all the organ systems of the body
• Mendelian inheritance (or genetics)


  A type of biological inheritance following the principles originally proposed by Gregor Mendel, a Moravian Augustinian friar, in 1865 and 1866 using pea plants
• 1915

  Mendel's theories were integrated with the Boveri–Sutton chromosome theory of inheritance by Thomas Hunt Morgan
• Complete dominance


  One allele (the Dominant allele represented by a CAPITAL Letter) completely masks another (the Recessive allele, represented by a small letter)
• Complete dominance


  • R = round seed; r = wrinkled seed
  • R = round seed; r = wrinkled seed
• Genotype


  The genetic composition of the alleles of the individual
• Phenotype


  The physical appearance of the individual
• Homozygous


  The two alleles are the same (both capitalized or small letter)
• Heterozygous


  The two alleles are of different types, (one is capitalized and its partner is in small letters) its a mixture of both dominant and recessive alleles.
• Pea flower color


  • P (purple) - dominant; p (white) - recessive
  • PP - Purple; Pp - Purple; pp - white
• Incomplete dominance


  A dominant allele (Capitalized) does not completely mask the effects of a recessive allele (small letters), and the organism's resulting physical appearance shows a blending of both alleles
• Incomplete dominance


  • RR = red rose flower; Rr = Pink flower; rr = White flower
  • WW - curly hair; Ww - wavy hair; ww - straight hair
• Co-dominance


  Both alleles are dominant, and they are both expressed in the organisms
• Co-dominance


  • Cow with brown and white skin; Flowers with both red and white petals
  • Human Blood Type groups: Allele A, B and O. Allele A and B are dominant, Allele O is recessive.

  
• Wrong mixing of blood can cause blood coagulation, which leads to death.
• There is also a Rhesus factor in blood, which is either RH + or RH -
• Sex-linked traits


  Genetic traits that are found in the X or Y chromosomes, thus either the male (XY) OR female (XX) influence the inheritance of the traits
• Sex-linked traits


  • Hemophilia - is usually an inherited bleeding disorder in which the blood does not clot properly. Hemophilia mutant gene is carried by the X chromosome.
• DNA


  The material that exists in every cell in your body that holds your genetic code. It makes up your body's instruction manual.

  
• DNA language


  Four chemical bases: Adenine (A), Cytosine (C), Thymine (T), Guanine (G)

  
• DNA constantly replicates itself by making hand-written copies of your body's instruction manual using the chunks of bases that form the words. There are an estimated 3 billion bases in a human's body. About 99% of those bases are the same in every person. The remaining 1% is what makes you unique.
• Triplet code


  Nucleic acids are read in threes (3's) by ribosomes, and each 3 letter code represents a specific Amino Acid which is, when forms into long chains, becomes a protein.
• Genes


  The building blocks for your body. Some genes give the instructions to make proteins. Some genes code for RNA, which does other jobs. Some genes are switches which turn other genes ON or OFF.

  
• You inherit your genes from your parents. You receive one copy of a gene from each parent (one from the egg from your mother and one from the sperm from your father). There are approximately 20,000 to 25,000 genes in your body.
• Chromosomes


  Structures that look like thread, which live in the nucleus (center) of cells. One molecule of DNA and one protein make up one chromosome.
• Humans should have 23 pairs of chromosomes (46 total). Chromosomes divide into 22 numbered pairs (autosomes) and one pair of sex chromosomes (X and Y).
• Although rare, errors occur when cells divide and replicate, so people might have an additional chromosome attached to a pair (trisomy) or one less chromosome on a pair (monosomy).
• Relationship and function of DNA, genes and chromosomes

  Chromosomes carry DNA in cells. DNA is responsible for building and maintaining your human structure. Genes are segments of your DNA, which give you physical characteristics that make you unique. Together, your body has a complete instruction manual that tells your cells how to behave.

  
• DNA can be found in each cell in your body. The majority of your DNA resides in the nucleus (center) of each cell in your body and some DNA lives in the mitochondria (little organelles inside of your cells that produce energy).

  
• Your DNA structure is made up of a double helix shape.
• Chromosome


  One of the threadlike structures in the nucleus of a cell that carries the genes in a linear order
• People might have an additional chromosome attached to a pair (trisomy) or one less chromosome on a pair (monosomy)
• DNA


  The molecule that carries the genetic instructions for the development and functioning of living organisms

  
• Genes


  Segments of DNA that encode the information required to produce a specific protein

  
• DNA, genes and chromosomes


  Work together to make you who you are
• Chromosomes carry DNA in cells

  
• DNA is responsible for building and maintaining your human structure
• Genes are segments of your DNA, which give you physical characteristics that make you unique
• Your body has a complete instruction manual that tells your cells how to behave
• Nucleus


  The center of each cell in your body where the majority of DNA resides