Cell organization and embryonic development

• Examples of Prokaryotes include; Archaea, bacteria and cyanobacteria
• Examples of Eukaryotes include; Plants, Animals, Fungi and Protists
• Cell wall of prokaryotes are made of muramic acids
• Cell wall of eukaryotes are made
• Chlorophyll of prokaryotes are contained in the chromatophores
• Chlorophyll of eukaryotes are contained in chloroplasts.
• Prokaryotes lack nucleus
• Eukaryotes have a membrane bound nucleus
• DNA of prokaryotes lies in the cytoplasm
• DNA in eukaryotes are found in the nucleus
• Prokaryotes have single circular chromosome plasmid
• Eukaryotes have many linear chromosomes
• Prokaryotes do not have endoplasmic reticulum, mitochondria, chloroplast and golgi apparatus
• DNA replication in prokaryotes are unidirectional and occurs in the cell cytoplasm
• DNA replication in eukaryotes are bidirectional and occurs in the cell nucleus
• Transcription and translation in prokaryotes occur simultaneosly
• Transcription and translation in eukaryotes occur in a sequence
• Fungi are not mobile like animals and dont have a chloroplast like plants
• Protista is mobile like animals and have chloroplast like plansts
• Embryonic development is a series of changes an embryo undergoes as it becomes a foetus
• Embryogenesis is cell division and cellular differentiation of the embryo
• Zygote is the first stage of life
• the organs form in the embryonic stage
• the skeletal system forms in the foetal stage
• Cleavage is the mitotic cell division of the embryo which forms a solid, compact mass of 16 or more cells known as MORULA
• Blastulation is the process via which the morula turns into blastula
• Blastula is a hollow sphere of cells surrounding an inner fluid filled cavity called the blastocoel.
• Gastrulation is a stage in which cell movements result in a massive reorganization of the blastula into three layered structure known as GASTRULA.
• The differentiation of the gastrula into three germ layers results into ectoderm, mesoderm and endoderm
• Gastrulation creates a blastopore which is the opening to the archenteron
• Archenteron is the invangination of the mesoderm and endoderm cells that later become the digestive tract
• The mesoderm forms via differentiation of the endodermal cells that cover the dorsal region of

  the archenteron.
• At neurula stage in embryogenesis, the ectoderm differentiates into neural tissues (nervous

  tissues).
• Endoderm differentiates into lung cells, thyroid cells and digestive cells
• Mesoderm differentiates into cardia muscle cells, skeletal muscle cells, tubule cells of the kidney, red blood cells and smooth muscle cells
• Ectoderm differentiates into skin cells of epidermis, neuron on brain and pigment cells
• Difference between Cleavage and Mitosis

  Cleavage divides the hollow ball into many cells; there is no cell growth. In mitosis, cell

  division is accompanied with cell growth.
• A chemical used to stain animal cell parts for viewing under a microscope

  is called

  Methylene Blue
• iodine


  Stains carbohydrates in plant and animal specimens brown or blue-black.
• Eosin Y


  Stains alkaline cell parts (like cytoplasm) pink.