General Education Component

AREA: SCIENCE

FOCI: Biology and Genetics


KNOWLEDGE UPDATE


Science

· is a way of looking at the world around us
· is a way of trying to explain how the worlds operates
· careful observation of nature is one important aspect of science
· observation are made and then information is gathered and examined when research is carried out
· Experiment is an observation of some natural phenomenon that is carried out under controlled conditions so that it is possible to duplicate the results of the experiment and draw rational conclusion
· Science uses scientific method to grow. The phases of the scientific method are:
observation and description
searching for patterns and regularities
making generalizations and framing scientific laws
formulating hypothesis and theories
making predictions based on theories
testing predictions by experimentation

· scientists deal with variables – independent (factors in the experiment that can be changed), dependent(result or outcome), constant (not changed)
· science is either basic (seeks to find knowledge for the sake of knowing more about a particular type of matter) or applied (seek to find new knowledge for the purpose of solving a particular problem).
· Natural Sciences include physics, astronomy, geology, chemistry, biological sciences
· Technology puts both basic and applied sciences to work by producing material objects for use by people. Science is knowledge and technology is application of science in production of material objects
· the concern of science is the natural world, the natural phenomena that take place in planet earth
· planet earth is our home and its natural resources are finite
· All planets get energy from the sun. The earth is the only planet with living things, which inhabit water, land and air. Three-fourths of the earth’s surface is covered with water. The rest is the continent, which used to be one called pangea. Pangea was divided into plates. The plates moved gradually through several processes like continental drift, sea floor spreading, plate tectonics, etc. The plates float on the mantle. The mantle is a layer of hot, plastic-like rocks moving underneath the crust. There are mountains formed by pushing or faulting. Underneath the surface of the earth are subsurface activities like earthquake and volcanic activities. On the surface are external forces, which can topple lofty mountains.

· Each provides us with air to breathe, food to eat and water to drink. It gives us materials to build home and shelter, for clothes, and it provides us with many things that we need to enjoy. Every single one of us depends on the earth for life. We need space for home, to move around, to work, to farm, to establish factories, build road and for parks. Thus we, use lands, grow plants and herds of animals, cut down trees and other plants, dig coal, drill oils and mine rocks. All of these we get from Earth are called natural resources.

Ø The world’s population is expanding. By 2050, the population of the year 2000 will be doubled. Will there still food for everyone? Will the earth be still healthy and pleasant to live/Will there be clean water? Will there be enough fresh air?
Ø Life on earth is so complex. Man has tried to conquer the range of phenomena and explained the natural world. The tremendous development in science today is the sign of man’s attempt to conquer nature.

· Through its concerns, science has developed and progressed tremendously bringing forth the age of computers, which give us electronic cash registers, and array of video games. Government agencies and companies train commercial and military pilots on flight simulators, which create varying, weather conditions., flight tactics and detailed maps of airfield. Machine designers are computer graphics for drafting needs, and business makes financial prediction on the spot. Artist used computer and monitor instead of paintbrush and canvas.
· Medical diagnosis has advanced due to computer and technologies like MRI and CT scan to examine tumor, locate tumors, and take a look at blocked arteries with accuracy.
· Recombinant DNA or plasmid for biosynthesis of human insulin, vaccines, enzymes, etc.
· due to advances in recombinant DNA, plymerace chain reaction technique evolved to diagnose diseases more rapidly and accurately.
· Technologies which can be used to solve problems like murder, rape, paternity cases
· Early diagnosis of diseases phenylketunuria, Down’s syndrome, cancer
· Gene therapy gene-related diseases
· Agricultural biotechnology – vaccines, treatment of diseases, plants with built-in resistance to pesticides, drought, and salt, plants which produce their pesticides, plants which produce seeds and fruits with better nutritional properties
· Bioprocessing that bring plants engineered to produce products like human pharmaceuticals.
· Material science: liquid crystals, superconductors, ceramics, optic fibers, thin films, etc.

Ø Some technological ideas are outgrowth of scientific breakthroughs and some technology has developed independent of scientific knowledge by trail and error. Technology builds upon two existing-technology and science.
Ø What are some of the applications of Science today? You might have heard or artificial blood, bioremediation of wastes, materials science, etc. However, science brought forth bad effects. The first publicized incident due to carelessness or lack of knowledge is the famous Love Canal in Niagara Falls. Another one is the discovery of extremely high levels of dioxin in the solid of Times Beach, Missouri. This led to the relocation of 2000 people and purchase of the entire town of Times Beach by EPA. In December 1984, a liquid chemical called methyl isocyanate overheated in a storage tank at Union Carbibe Co. chemical plant in Bhopal, India. A poisonous gas entered the atmosphere and caused death of thousands Indian people who lived in the vicinity of the plant.
Ø The explosion and fire at the Chernobyl nuclear power plant in the former Soviet Union left a deadlt legacy. The accident was due to the cooling water that kept the uranium-containing fuel rods at a safe temperature in the fission reactor was accidentally cut-off. The fuel rod became very hot and water turned to steam and the chemical reaction occurred between the materials in the fuel rods and the graphite containing bricks that surrounded them. A mixture of explosive gases ignited, blowing off the building and igniting the graphite.

Ø The burning of oil wells and oil spills into the sea in the middle east during the Persian Gulf War brought havoc in the environment.
Ø In the Philippines, we are worried of Smokey mountains, the obnoxious atmosphere in Metropolis, the polluted bodies of water, open landfills, garbage in the metropolis, Ormoc City tragedy, 70% of Caraga region in February, 1999 was under water, Marcopper tragedy contaminant Boac river in Marinduque, cyanide fishing, Manila air is one of the world’s dirtiest air, landslide due to mining.

· Is there hope for these bad effects of technology. Of course!
· In 1971, some people started talking about sustainable development. One strategy is environmental education. Others are price tag of our natural resources, proper zoning, community participation, national park and other protected areas, proper harvest time of biodiversities, reforestation.
· In 1988, we signed with other countries the Montreal protocol
· In 1992 – the earth summit

I. Structural Levels of Organization
* Atom
* Element
* Simple molecules (H2O, CO2, O2, simple sugars, amino acids, fatty acids,
nucleotides)
* Organelle
* Cell
* Tissue
* Organ
* Organ System
* Organism
* Population
* Community
* Biosphere

II. Chemistry of the Cell

A. Inorganic Compounds

1. Water – most abundant substance of the living cell
universal solvent due to its polarity; ionic compounds or
electrolytes dissociate in water
high specific heat due to H-bonding, refers to the high heat energy
required to raise the temperature of a substance by a specific
amount
high latent heat of vaporization refers to high energy needed to
separate molecules from the liquid phase and move them into gas
phase
cohesion refers to mutual attraction between molecules
adhesion refers to the attraction of water to solid phase
high surface tension is a condition that exists at the air-water
interface wherein strong hydrogen bonding among water
molecules occur thereby minimizing surface area
2. Carbon Dioxide – principal raw materials for photosynthesis
3. Oxygen – requirement for cellular respiration

B. Organic Molecules

1. Carbohydrates – a.) monosaccharides – e.g. glucose, fructose, galactosen building units of carbohydrates
b. disaccharides – combination of two monosaccharides e.g. maltose, lactose and sucrose
c. polysaccharides – combination of several monosaccharides
e.g. starch and cellulose in plants, glycogen in animals
2. Lipids – fats and their derivatives – a fat molecule consists of three molecules of fatty acids and one molecule of glycerol
3. Proteins – Polymers of different types of amino acids
4. Nucleic acids – a.) Deoxyribose nucleic acid (DNA) – genetic materials replicating molecules b.) Ribose nucleic acid (RNA) – messenger RNA and ribosomal RNA

III. Cell Structure and Functions

1. Cell Wall – made up of cellulose indigestible; gives shape and support to the plant cells
2. Plasma membrane – continuous lipid bilayer intercalated with proteins, regulation of transport of substances in and out of the cell.
3. Cilia and flagella – locomotion and feeding
4. Ribosomes – protein synthesis
5. Endoplasmic reticulum – modification and transport of proteins and other secretory products
6. Mitochondria – cellular respiration
7. Golgi apparatus – secretion synthesis
8. Lysosomes – storage site of hydrolytic enzymes
9. Vacuoles – storage of water and food for excretion
10. Chloroplast – photosynthesis
11. Nuclear membrane – traffic control to and from cytoplasm
12. Nucleolus – production of ribosomes
13. Chromosomes – carrier of hereditary traits or genes

IV. Cell Physiology

1. Protein synthesis – a.) DNA replication – to form double –stranded chromosomes (i.e. two chromatids per chromosomes); b.) Transcription – genetic information in DNA becomes incorporated in the messenger RNA c.) Translation – the codon in the messenger RNA is used to determine the sequence of amino acids in protein
2. Photosynthesis – process in which light energy and chlorophyll are used to manufacture carbohydrates out of CO2 and water.. a.) Light Reaction – chlorophyll traps light energy; photolysis-splitting of water molecules into hydrogen and oxygen atoms, b.) Dark reaction – CO2 fixation into carbohydrates
3. Cellular Respiration – oxidation of organic compounds with the release of chemical energy; anaerobic and aerobic respiration
4. Cell reproduction – a.) mitosis – somatic cell division maintains the same number and kind of chromosomes as in the parent cell, diploid number of chromosomes; b.) meiosis – reproductive cell division in matured egg and sperm cells; reproduction in the number of chromosomes in the parent cell (haploid number)


V. Plant Tissues and Organ System

1. Meristematic tissue – a.) apical meristems – for the increase in the length of the plant body at the tips of the roots and stems; b.) lateral meristems – for the increase in the girth of the plant body
2. Simple permanent tissues – a.) epidermis – principal surface tissue of young and herbaceous roots and stems and flowers, b.) parenchymathin primary wall with large vacuoles; c.) collenchyma – primary walls with large vacuoles ; c.) collenchyma – primary walls irregularly thickened at the corners where the cells meet; d.) sclerenchyma – thick secondary walls and dead at maturity
3. Complex permanent tissue – a.) periderm – consists of cork, cork cambium and phelloderm, replaces the epidermis in mature woody roots and stems; b.) vascular tissues – 1.) Phloem – consists of parenchyma, sclerenchyma, sieve and companion cells; 2.) xylem – consists of parenchyma, sclerenchyma, tracheids and vessel elements

a. Bark consists of periderm and secondary phloem.
b. Wood consists of secondary xylem with annual rings
c. Sexual reproduction in flowering plants: Double fertilization – union of sperm and egg to form a diploid zygote that gives rise to the embryo, and the union of another sperm and the 2 polar nuclei forms the triploid endosperm.
d. Seed consists of seed coat, cotyledon, endosperm and embryo. Embryo consists of the plumule, hypocotyls and radicle.


VI. Animal Tissues and Organ Systems

1. Integumentary system – a.) epidermis – simple and stratified epithelial tissues; b.) dermis – sweat glands, oil glands, nerve, blood vessels, hair folliclen c.) subcutaneous tissue – adipose / fatty issues
2. Skeletal system – consists of bones that are hard due to solid matrix, which contains inorganic compounds such as calcium carbonate and calcium phosphate
3. Muscular system – a.) skeletal muscles – attached to the bones; voluntary; voluntary movement ; b.) smooth/visceral muscles-blood vessels, lymphatic vessels, gastrointestinal tracy; involuntary movement of vital fluid; c.) cardiac muscles – walls of the heart; pumping action to the heart.
4. Digestive system – mechanical and chemical digestion of food

a. Oral cavity – incisors, canines, premolars and molars; salivary glands secrete saliva with salivary amylase or ptyalin that converts starch to maltose.
b. Esophagus – peristaltic movement to push the bolus down
c. Stomach – gastric glands secrete gastric juice that contains pepsin, which digest protein to peptones and proteoses
d. Small intestines – intestinal glands secrete intestinal juice that contains the following digestive enzymes a.) erepsin digests petides to amino acid ; b.) maltase digest maltose to glucose; c.) lactase digest lactose to glucose and galactose; d.) sucrase digest sucrose to glucose and fructose.
e. Seed consists of seed coat, cotyledon, endosperm and embryo. Embryo consists of the plumule, hypocotyls and radicle.



VII. Animal Tissues and Organ Systems

1. Integumentary System – a.) epidemis – simple and stratified epithelial tissues; b.) dermis – sweat glands, oil glands, nerve, blood vessels, hair folliclen
2. Skeletal system – consists of bones that are hard due to solid matrix, which contains inorganic compounds such as calcium carbonate and calcium phosphate
3. Muscular system – a.) skeletal muscles – attached to the bones; voluntary movement; b.) smooth/visceral muscles – blood vessels, lymphatic vessels, gastrointestinal tract; involuntary movement of vital fluid; c.) cardiac muscles – walls of the heart, pumping action of the heart.
4. Digestive system – mechanical and chemical digestion of food
a. Oral cavity – incisors, canines, premolars and molars, salivary glands secrete saliva with salivary amylase or ptyalin that converts starch to maltose.
b. Esophagus – peristaltic movement to push the bolus down
c. Stomach – gastric glands, secrete gastric juice that contains pepsin, which digest protein to peptones and proteoses
d. Small intestines – intestinal glands secrete intestinal juice that contains the following digestive enzymes: a.) erepsin digests peptides to amino acid; b.) maltase digests maltose to glucose c.) lactase digests lactose to glucose and galactose; d.) sucrase digest sucrose to glucose and fructose
5. Circulatory and Lymphatic system – a.) blood – consists of plasma, erythrocytes, leukocytes and thrombocytes; b.) blood vessels – veins, venules, arteries, arterioles and blood capillaries; c.) heart-right atria and left ventricles, tricuspid and mitral valves, semilunar valves d.) lymph-“colorless blood” e.) lymphatic vessels – lymphatic capillaries and veins; f.) lymph ducts and lymph nodes
6. Respiratory system – a.) external respiration – exchange of gases between blood in the pulmonary capillaries and air in the alveoli; formation of oxygenated blood; b.) internal respiration – exchange of gases between the blood and the various tissue cells; formation of deoxygenated blood
7. Excretory system – a.) defecation – expulsion of feces; colon, rectum, anal canal and anus; b.) mictirition –urination; kidneys ureters, urinary bladder and urethra
8. Reproductive system – a.) spermatogenesis – development of mature spermatozoa from spermatogonia by mitosis, meiosis and differentiation; b.) oogenesis – development of mature ova from oogonia by mitosis and meiosis
9. Nervous system – nerves and neurons
a. Reflex arc – short circuit of nervous impulse from receptor cell to effector
b. Axon of one neuron synapses with the dendrites or cell body of other neurons
10. Endocrine system – endocrine glands are ductless glands that secrete internally and convey hormones directly into the blood in the capillaries supplying the endocrine tissues
a. Pancreas
Glucagon – glucagons to glucose conversion
Insulin – glucose to glycogen conversion; diabetes mellitus and
Hypoglycemia
b. Thyroid
Thyroxin- stimulates respiration / metabolism; hyper- and hypothyroidism, goiter, cretinism; myxedema
c. Parathyroid
Parathormone – controls Ca metabolism; hyperthyroidism (fractured bones)
d. Adrenal cortex
Cortisone – controls metabolism of water, minerals and carbohydrates ; controls kidney functions; Addison’s Disease (fatigue, loss of weight and change of skin)
e. Adrenal medulla
Adrenaline, noradrenaline –“fight or flight” reaction
f. Anterior pituitary
TSH (Thyrotrophic) stimulates thyroid
ACTH (Adrenocorticotrophic) stimulates adrenal cortex
FSH (Follicle-stimulating) – stimulates ovarian follicle and spermatogenesis
LH (Luteinizing) – stimulates corpus luteum in female and secretion of testosterone in male
Prolactin – stimulates milk secretion
Somatotrophic – regulates growth of skeleton; dwarfism and gigantism
g. Posterior pituitary
Oxytocin – stimulates smooth muscles and contractoion of uterus
ADH (Antidiuretic)/vasopressin – water reabsorption by kidneys; Diabetes insipidus (ADH deficiency)
h. Testes
Testosterone – maintains male sex characteristics
i. Ovaries
Progesterone (corpus luteum) – maintains growth of the uterus
Estrogen – (ovarian follicle) maintains females characteristics


VIII. Biological Diversity

1. Monerans – bacteria, blue-green algae; no cytoplasmic streaming, no distinct nucleus; lack endoplasmic reticulum, mitochondria, golgi bodies; abundant ribosomes
2. Protists – algae and protozoans; definite nucleus, with all the cytoplasmic organelles
3. Plants
· bryophytes – mosses, liverworts and hornworts; adapted only to moist habitat; lack vascular tissues;
· Tracheophytes – vascular plants; gymnosperms and angiosperms

4. Animals
· Poriferans – body perforated with flagella-lined openings; soft body parts supported with skeleton made of calcareous and siliceous needles; scyphavenus’s flower basket sponges
· Coelenterates – mesoglea in between two layers; nematocysts on tentacles; polymorphism; hydra, sea anemones, corals and jellyfish
· Platyhelminthes – flatworm with bilateral symmetry and a mesoderm, no body cavity; free living and parasitic; planaria, fluke, tapeworm
· Aschelminthes – tubular digestive tractwith botyh mouth and anus; roundworms hookworms, ascaris
· Ennelids – body divided into metameres or segments with duplication of body parts in each segment; true coilom; well-developed circulatory system; earthworm, leech
· Arthropods – jointed appendages , segmented bodies (head, thorax/caphalothorax and abdomen), chitinous exoskeleton; ventral nerve cord and dorsal heart; spider, scorpion, ticks, mites, crustaceans, centipedes, millipedes and insects
· Molluscs – fleshy mantle that secretes the calcareous shell,ventral muscular foot, snails, slugs, bivalves, squid and octopus.
· Echinoderms – hard, calcareous spines that protrude through the skin, radial symmetry, water vascular system and tube feet; starfish, brittle star, sea urchin, sea cucumber
· Chordates – flexible, supporting notochord; dorsal tubular nerve cord; vertebrates: a.) cartilaginous fish – shark and ray; b.) bony fish; c.) amphibians – larvae are aquatic and lungs present in adult; frogs, toads, salamanders; d.) reptiles – body covered by scales or bony plates; snake, lizard, turtle; e.) aves – body with feathers and front appendages modified into wings; birds; f.) mammals – mammary glands; body with hair, viviparous reproduction; highly developed cerebrum; koala, elephant, bat, rat, cow, rabbit, man.
5. Fungi – network of hyphae called mycelium; “colorless protests” nonphotosynthetic; molds, mushroom
6. Virus – composed of inner nucleic acid core (DNA or RNA) and an outer protein coat; parasitic


IX. Genetics and Evolution

1. Chromosomes a.) autosomes – somatic chromosomes b.) sex chromosomes in man, there are 22 pairs of autosomes and a pair of sex chromosomes (22 and X chromosomes in egg, 22 and X or Y in sperm)
2. Sex chromosomes aberration – non-disjunction of the producing egg or sperm cell that may contain both XXX or XY and the other half none.
3. Point or gene mutation may involve change in a single or few nucleotide bases or may involve gross modifications of chromosomal structure or number as in chromosomal aberrations brought a brought by chemical pollution, ionizing radiation, drug abuse, radioactive waste, etc.
4. Mendelian Genetic a.) law of segregation – separation of the pair of genes (alleles) during gametogenesis, b.) law of independent assortment – the distribution of genes in the resulting gametes is at random.
5. Non-mendelian Genetics – a.) Incomplete dominance – phenotype of heterozygote is intermediate between phenotypes of the two homozygotest a cross between red and white flower produced pink flowers b.) Codominance – phenotype of the hybrid is a mixture of red and white haired cattle produced a roan hybrid with a mixture of red and white c.) multiple alleles – any 3 or more genes occupy the same iocus in a given pair of chromosomes e.g. 3 alleles of blood type – A,B and O d.) sex-linked genes or x-linked genes – genes exclusively in X chromosomes; e.g. hemophilia; c.) Lolandric or Y-linked genes-genes occurring in Y chromosomes produce effects only in males e.g. hypertrichosis (hair arising from ear); f.) sex-influence genes – genes in which the expression or dominance depends on the sex of the bearer. E,g. pattern baldness in males
6. If two individuals of opposite sex are able to interbreed and produce fertile offspring then they belong to the same species.
7. Speciation is the formation of new species and the development of species diversity occurs when gene flow within the common pool is interrupted by isolating mechanisms. When isolation occurs through geographic separation of populations descended from a common ancestor, allopathic speciation may result. When isolation occurs through ecological or genetic means within the same area, sympatric speciation is a possibility.