PRELIMS CYTO TOPIC 2

CLASSICAL GENETICS

• Chromosomal theory of inheritance

MOLECULAR GENETICS

• Study of the genetic material

EVOLUTIONARY GENETICS

• Study of the mechanisms of evolutionary
  change, or changes.

GREGOR MENDEL

• discovered the basic rules of transmission
  genetics.
• Experiments with the garden pea plant -
  Pisum sativum (italicized)
• He found traits such as pod color, were
  controlled by genetic elements that now
  we call genes.

Alleles

• alternative forms of a gene

(diploid state);

• MENDEL also discovered
  that adult organisms
  have two copies of each
  gene called

(haploid
state)

• Gametes receive just one
  of two copies(diploid).
  The zygote gets one copy from each gamete,
  reconstituting the diploid number

CHROMOSOMAL MAPPING

• The ability to locate the relative positions
  of genes on chromosomes by crossing
  certain organisms.

CHROMOSOMAL THEORY OF
INHERITANCE

• Genes are locate at fixed positions on
  chromosmes in a linear order.
• As seen in this diagram of chromosome 2
  of Drosophila melanogaster, the
  common fruit fly.
• The numbers represent the map units.

PROTEINS

• Naturally occurring, extremely complex
  substance that consist of amino acid
  residues joined by peptide bonds.
  Examples: Hemoglobin, Albumin, Actin,
  Tubulin, Keratin

MOLECULAR GENETICS

• Study of the genetic material
• Is the branch of genetics that
  investigates the chemical and physical
  nature of genes and the mechanisms by
  which genes control development,
  growth, and physiology.

double-stranded DNA

• With the exception of some viruses, the
  genetic material of all cellular organisms
  is (what number of stranded DNA)

• James Watson and Francis Crick

deduced the double-stranded DNA structure in 1953, ushering
the era of modern genetics

COVID-19 SARS-CoV 2

• A type of RNA virus detected using
  Reverse Transcriptase Polymerase Chain
  Reaction

NUCLEIC ACIDS

• Is a complex organic substance present
  in living cells, whose molecules consist of
  many nucleotides linked in a long chain.

○ Deoxyribonucleic acid (DNA)
○ Ribonucleic acid (RNA)

2 main types of nucleic acid:

Nucleotides

• building blocks of DNA

○ Phosphate backbone
○ Deoxyribose (sugar)
○ Nitrogenous base (purine or
pyrimidine)

3 components of a nucleotide:

PURINE

Adenine (A)
Guanine (G)

PYRIMIDINE

Cytosine (C)
Thymine (T)

DNA & RNA

• Both are examples of nucleic acids
• Both are made up of nucleotides

DNA nucleotide

1.Phosphate

2. Sugar (Deoxyribose)
3. Nitrogenous base (A, G, C, T)

RNA nucleotide

1. Phosphate
2. Sugar (Ribose)
3. Nitrogenous base (A,G,C,U)

DNA strands

• mainly double-stranded but can exist as
  single-stranded DNA strands

RNA strands

• mainly single-stranded but can loop
  around themselves forming a
  double-stranded nature

COMPLEMENTARITY

• A relationship called complementarity
  exists between bases.
• If one base pair is adenine (A), the other
  must be thymine (T), if one base is
  guanine (G), the other must be cytosine
  (C).

MUTATION

• A change in one of the bases, could result
  from either an error in base pairing or
  some damage to the DNA that was not
  repaired by the body.

RNA (RIBONUCLEIC ACID)

• is a polymer of nucleotides similar to DNA
• The function of RNA depends on the type of RNA
• Single-stranded and has Uracil instead of Thymine

○ mRNA (messenger RNA)

messenger

○ rRNA (ribosomal RNA)
○ tRNA (transfer RNA)

formation
of protein

EVOLUTIONARY GENETICS

• Evolution is the change in allelic
  frequencies in a population over time.
• Charles Darwin described evolution as
  the result of natural selection.

THEORY OF NATURAL SELECTION

• Developed by Charles Darwin
• Natural selection is the process through
  which species adapt to their
  environments. It is the engine that drives
  evolution

NEO-DARWINISM

• Modified theory of Darwinism explaining
  the origin of species on a genetic basis.
• A cohesive evolutionary theory that
  integrates Darwinian evolution and
  Mendelian genetics

PUNCTUATED EQUILIBRIUM

• Suggested that most evolutionary
  change is not gradual, and occurs in
  short, rapid burst, followed by long
  periods of very little change.

SOCIOBIOLOGY

• Suggest that social behavior is under
  genetic control and is acted upon by
  natural selection, as in any morphological
  or physiological trait.
  I.e.: Affection, friendship, reproduction,