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Biology
Books- Extracts.
Reviews and some contents. Head Strong by Dave Asprey. Chapter 1. Head start. Dr. Paul Mac Lian introduced the Triune brain model in 1960.
2. Mammalian brain control instincts. Fear, Food and reproduction. 3. Human brain resist some of the reactions due to false alarms. Each decision requires a lot of energy. When u r tired, hungry or have already made a lot of decisions u run out of energy and make bad decisions. Chapter 2. Mighty mitochondria. Earth was covered with warm seas. Atmosphere was oxygen. One type of bacteria learned to use oxygen to get energy. They created ATP. A small purple bacterium entered became embedded in another type of cell. This combination evolved to form animals. These bacteria are the mitochondria in our cells. Chapter 3. Become a neuromaster. Researchers have found that progesterone , the female hormone, signals oligodendroglia to initiate remyelination. Bioflavonoids in citrus fruits and some veggies are essential to keep neurons alive. So are the Polyphenols in coffee, chocolate, blueberries and grapes. Anything we do to avoid chronic stress will help to create more brain cells.exercise increases neurogenesis. A fun environment helps. Tips. 1, Eat saturated fat from grass fed butter, and meat, 2. Avoid sugar 3. Manage your stress. 4. Have more sex. Chapter 4. Inflammation. The brain is the first part of the body to suffer when chronically inflamed. When mitochondria are inflamed electrons have to travel further to get to the same place. Tips:- Spend some time outdoors barefoot to soak up the earth’s negative charge. Chapter 5. Brain fuel. Polyphenols are antioxidants that protect your gut , increase your rate of neurogenesis, play a role in apoptosis. Mitochondria make energy more efficiently with ketones than with glucose. Do these:- Eat low sugar fruits and veggies with a healthy fat such as grass fed butter. Eat more fish. Restrict carbohydrates. Chapter 6. Brain inhibiting foods. Dairy protein, gluten, transfats and vegetable oils cause inlammation. Mold toxins are particularly toxic.Healthy fats are damaged by high temperatures, Tips:- Stop using art sweeteners. They are toxic. Never eat fried food. Toxic. Buy organic. Chapter 7. Avoid toxins and improve your body’s detox systems. About 25% are genetically sensitive to mold. Mold toxins , heavy metals, and some drugs are directly toxic. Toxins are stored in fat. Breaking up fat detox your body. Chapter 8 Your brain on light, air and cold. LEd and CFL blbs have too much blue.which damages mitochondria. Chapter 9 Focus on quality of sleep. Meditate and exercjse.  Your Body Extracted from 100 things you never knew. 1. Tooth enamel is the toughest material in the body. 2.Skeletal muscle makes 40 - 50% of the mass of males and 30 - 40 % in females. 3. Women’s bodies have a lower centre of gravity. 4. Sweat glands releases 2 cups of water per day. 5. Oxytocin bolsters emotional bonding between individuals. 6. The brain can function up to 10 seconds after the blood supply is cut off. 7. Brain is only 2% of the body but it uses 20% of the O2 and glucose. 8. Sleep deprivation is connected to a loss in the no of immune cells. 9. Adults have about 4 -5 Litres of blood. 10. Anger and fear increases the heartbeat by 30 -49 beats a minute. 11. The heart muscles grown in a culture beats spontaneously. 12. A normal resting heart rate for adults ranges from 60 to 100 beats per minute. . 13. Allergies decrease in elderly. |
Genetics-ll.
Heredity  Prior to the study of this lesson it is essential to be familiar with these terms.
All members in a specie are not the same. There are minor differences. Such variations help the survival of the species. For example if a disease spreads, every individual will not be susceptible to the same extent. Even when a large percentage gets wiped out a few individuals at least will survive and continue the specie. This is how the evolution takes place. The surviving individuals will be slightly different to the original stock. The traits inherited are of two kinds. 1.Continuous traits. Characteristics show a wide range of differences. Eg. Size, skin colour, inteligence. 2. Discrete traits. (Discontinuous) There are only two possibilities. A rabbit can be either white or black. Eg. Ability to roll the tongue. How alleles pass on traits The inheritance of a trait is governed by the 2 genes, which are termed alleles. These two come from the two parents. In a pair one allele may be dominant while the other is recessive. If a dominant allele is present it will always exhibit in the phenotype. The recessive allele will only function in the absence of a dominant allele.
We can illustrate this if we consider the dominant factor brown eyes as ‘R’ and the recessive factor as simple ‘r’ for blue eyes.
Gregor Mendel discovered these rules of inheritance long before the discovery of the genes. According to the theory of Mendelian inheritance, variations in phenotype are due to variations in the genotype. Mendel's Experiment. He grew two varieties, of the pea plants, having purple and white flowers, allowing them to self pollinate so that he could obtain pure bred specimens. Then he systematically recorded the passing of seven characteristics (which we now call traits). Let us select one trait to show what he discovered.In This case two pure bred varieties are taken and the flowers are cross pollinated. While capital B represents a dominant blue colour , simple w' is for a recessive gene. Combination of the plants shown in the punnet can produce only blue flowers. This does not mean that the allele to produce white flowers has vanished. It will be there and exhibit it self when the daughter plants are crossed. Mendel's Law of Dominance. .  All BLUE, 'cause that was the dominant in the two pure breds, Look at the Genotype. Recesive gene is there in every one. After cross pollination of two pure forms having different discrete traits , only one form will appear in the first order of off springs.  Mendel's Law of segregation. During reduction division to form gametes(Sex cells) two alleles coded for a trait separate.On fertilization they combine. The off springs always bear the ratio 3:1 for dominant:recessive alleles. Sex determination  Out of the 46 genes of an individual 22 pairs would be identical in males and females. These are called autosomes. The 23rd pair which is one that determines the sex would be different. This diagram shows the difference. In females sex cells are identical, X and X, while males have two types, X and Y. Gametes form after reduction division( meiosis) do not have a pair of chromosomes but only one. So the egg cells contain only X chromosomes while a male will have half the number of sperms with X and the other half with Y.
X linked chromosomes are also responsible for some abnormalities such as haemophilia and a form of baldness.The Y chromosome has the genes for male characteristics. In the absence of Y, the embryo would produce a female. As the males carry only one copy of X, they are more liable to get hereditary disorders such as haemophilia and colour blindness.. When normal cells are stained , only in the case of female cells a stained body becomes visible. This is really the condensed form of an X chromosome. This has become invaluable in some legal cases.Protein synthesis. This is the process of making proteins according to the information coded in DNA.. The intermediary for the making of new protein is the RNA.( Ribonucleic acid.)
RNA varies from DNA from the following: 1.They are single stranded. 2. The base cell Thymine is changed to Uracil. 3.Contains the sugar Ribose instead of deoxyribose. Three bases in order is sufficient for a particular amino acid. These are known as triplets or codons. What are codons or Triplets ? There are only 20 amino acids in human beings. They are listed here.
Step 1.Transcription. For the genetic code to be active the two strands have to open up. This happens at different places at the same time catalyzed by an enzyme Helicase. Any one of these strands is used as a template to make a molecule of ribonucleic acid which would be known as mRNA. (‘m’ for messenger) This copy, called a messenger RNA (mRNA) molecule, leaves the cell nucleus and enters the cytoplasm, where it directs the synthesis of the protein, which it encodes. This process is assisted by an enzyme called Polymerase . One end of a DNA polymer contains an exposed hydroxyl group on the deoxyribose; this is known as the 3' end of the molecule. The other end contains an exposed phosphate group; this is the 5' end. So processes such as DNA replication occur in only one direction. All nucleic acid synthesis in a cell occurs in the 5' to 3' direction.Step 2. Translation This copy, called a messenger RNA (mRNA) molecule, leaves the cell nucleus and enters the cytoplasm, where it directs the synthesis of the protein, which it encodes. Translation is the process of translating the sequence of a messenger RNA (mRNA) molecule to a sequence of amino acids during protein synthesis. The genetic code describes the relationship between the sequence of base pairs in a gene and the corresponding amino acid sequence that it encodes. In the cell cytoplasm, the ribosome reads the sequence of the mRNA in groups of three bases to assemble the protein. A gene can be switched on and off. When a gene is active, the coding and non-coding sequences are copied in a process called transcription, producing an RNA copy of the gene's information. The mRNA then leaves the nucleus to the cytoplasm where it is translated via the use of tRNA and ribosomes and amino acids to translate the mRNA strand into a protein. When the gene is turned off, a repressor molecule is formed which stops protein synthesis as it covers the promoter site. There are only 20 Amino acids among all living Gregor Mendel first came across the idea of genes, in the 1860s. He studied inheritance in pea plants and hypothesized a factor that conveys traits from parent to offspring. Mendel was also the first to hypothesize independent assortment, the distinction between dominant and recessive traits, the distinction between a heterozygote (A person carrying two different forms of a gene inherited from father and the mother) and homozygote (A person having two similar genes inherited from the two parents), which is the genotype (the genetic material of an organism) and phenotype (the visible traits of that organism). According to the theory of Mendelian inheritance, variations in phenotype are due to variations in genotype, or the organism's particular set of genes, each of which specifies a particular trait. Different forms of a gene, which may give rise to different phenotypes, are known as alleles. Organisms such as the pea plants Mendel worked on, along with many plants and animals, have two alleles for each trait, one inherited from each parent. Alleles may be dominant or recessive; dominant alleles give rise to their corresponding phenotypes when paired with any other allele for the same trait, whereas recessive alleles give rise to their corresponding phenotype only when paired with another copy of the same allele. But this is not always the case; in this situation the alleles are completely dominant. In other cases the alleles could be incompletely dominant or co-dominant. Incomplete dominance is when a characteristic in the heterozygote s intermediate in the degree between the two homozygotes. And co-dominance is when the heterozygote simultaneously expresses 2 alleles that have different kinds of effect. Chromosomes within cells are the carriers of genetic material, and they are made of DNA (deoxyribonucleic acid). DNA consists of a chain made from four types of nucleotide subunits: i.Adenine, ii.Cytosine, iii.Guanine, and iv.Thymine. Each nucleotide sub-unit consists of three components: i. a phosphate group, ii. deoxyribose sugar ring, and a iii. base. (Adenine and guanine are purines, and cytosine and thymine are pyrimidines.) The DNA in a cell has double helix structure, in which two individual DNA strands twist around each other in a right-handed spiral. In this structure, the base pairing rules specify that guanine pairs with cytosine and adenine pairs with thymine (each pair contains one purine and one pyrimidine). The base pairing between guanine and cytosine forms three hydrogen bonds, whereas the base pairing between adenine and thymine forms two hydrogen bonds. The two strands in a double helix are complementary.  Q.1.0 Give a single word for these: 1.The functioning and dormant genetic material present in an organism. 2.The functioning or visible traits of that organism. The form that is shown. 3.Different forms of a gene, which may give rise to different phenotypes, 4. Two of the same alleles at a specific locus. 5. Two different alleles at a specific locus. 6. A characteristic showing a wide range of differences. 7. A trait showing only two variations. 8. The process of making proteins according to the information coded in DNA. 9. The process by which the information in a strand of DNA is copied into a new molecule of messenger RNA (mRNA). 10. Synthesis of amino acids according to a an mRNA sequence. 3x10-30 marks. Q. 2.0 MCQ.
A- WW or Wb, B- WW Only. C- Wb only D- Cannot be determined.
4x5=20 marks. Q.3.0 Recognize these cells and answer the questions below. There can be more than one letter to an answer. Name the following:-
3x8 = 24 maeks. Q.4.0 Complete these punnets.and comment on the offsprings produced using the table given. Bd = Black dominant. Wr = White recessive.
Q.5.0 Answer these.
2x5 =10 marks. For answers click:- Answers-Bio. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Biology terms M to Z.
M..
Mutations often lead to evolution. The process may produce an individual more suitable for the environment. N
This is the inflamation of kidneys due to infection or immunity dis orders.
Fig. Structure of the nucleus. This is the most important organelle in a cell.It contains genetic material, chromosomes. O
P
 Fig. Structure of Maize (monocot) and Bean (dicot) seeds.
· Prebiotics
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R
This process conforms to two important functions.
Reproduction The ability to make exact copies of oneself may be considered as the specific characteristic of living things. There are many ways of performing this most important task. Let us consider some of them. A = Asexual Methods 1. Fission – This is merely dividing a cell and its contents into two or more cells. This process is almost identical to growth. Spirogyra, an algae consists of a row of identical cells. When the cells divide yet they are attached to the filament we call it growth. If they separate and start life as new individuals it amounts to reproduction. In the case of amoeba, a protozoan, binary fission amounts to reproduction. 2. Budding – This is very common in plants and yeast like specimens but rare among animals. Hydra is a fresh water animal that form new individuals by budding. 3. Vegetative Propagation-This includes all types of producing new plants from a parent plant. Here are sme examples. Runners in strawberry. Leaves in Bryophillum and Begonia. Suckers in Banana. Bulbs in garlic Stem cuttings in Roses. B- Sexual Method 4. This method involves the formation of gametes from two individuals and uniting them in a process called fertilization. Gametes contain only half the number of chromosomes which are formed by Reduction Division of cells. The process is also called meiosis. The gametes may be similar or differentiated as male and female. The individual formed by fertilization is called Zygote and would contain a diploid number of chromosomes. Refer:- Cell division S
T
Transpiration Turgor Pressure
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Plant Kingdom
 Fig 1 The 5 kingdoms of living things. Out of these, plant kingdom, is the most mportant.  Fig. The food synthesizing system in the world. 99.9 % of the food is made this way.
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Bacteriophages.
“ Drinking water from the Holy Rivers like Ganges & Yamuna, could cure cholera”, Fact or fiction?  Fig.1. Phages landing on a bacterium. Courtsey:- Phages.org. Ernest Hankin (UK), in 1896 found that cholera bacteria that thrived in tap water had no success in Ganges water. He found that even the filtered river water could destroy Vibrio cholerae bacteria, unless he boiled it. The agent that killed bacteria was only discovered in 1916 by Felix d'Herelle (Can) from Pasteur Institute in Paris. These have been named as Bacteriophages as they destroy bacteria. They cannot even be classified as living things. They are described as ,’ Nano particles capable of self replicating”. Fig.2 Three phages have landed on the surface of a Bacterium.Courtsey:- Phages.org.A baceriophage is very much smaller than a bacteria. They are really viruses. Cousins of those that cause, flu, pox and ebola.No reason to worry; phages do not attack human cells.The longest war in recorded history may be 100 yr war, but there is a war that had been raging for millions of years. The war between the phages and bacteria. It has been estimated that phages slaughter half the total number of bacteria in 2 days. Then the question arises, “Why won’t the bacteria become extinct?. There are two reasons for this.
While the war rages What shall we do ?
Fig.3 A phage attacking a bacteria.The obvious thing we have to do is to take the side of the Phages. They do no harm to us unlike some bacteria who are infectious. Phage TherapyPhage therapy started before the discovery of antibiotics. The difficulty with phages is that they are highly specific.One kind of a phage can generally destroy only one type of bacteria. But now when some bacteria develop resistance even to the strongest antibiotics, the doctors are inclined to go back to phage therapy. Phages can change their mode of attack when the enemy changes unlike the antibiotics. |
Bats
 Flying foxes. Fig.1 Indian flying fox. Courtsey: batworlds.com Bats were considered as,” Demon’s Angels”. They are unusual; flying at dusk and roosting upside down. Biologists have introduced sufficient evidence now for us to change that attitude. Bats carry deadly viruses including ebola,SARS etc. but they do not become sick. This has baffled virologists. Although colonies of bats have been destroyed in the recent years by man the scientists who have studied them say they cannot pass the disease causing viruses directly to man. On the other hand those who have studied viruses are of opinion that they are vital to our environment. They eat tons of agricultural pests in a single night. They pollinate flowers and help the plants by dispersing seeds and fruits.
Anthony King writing an article in the New Scientist says, quotes the following scientists. James Wood. University of Cambridge. “ Bats carry rabies virus yet they have developed immunity” Linfa Wang. University of Singapore. “Injecting bacterial toxins to animals normally triggers a reaction.When bats are injected they don’t get even a fever.It is hard to make them sick. Trying to control emerging diseases by killing bats may be the worst thing we can do” Reference. CLICK HERE to wach a webcast "Project Edubat – Education Taking Flight” to learn more about these important animals. |
Fungi
Kingdom Fungi Fig.1 Largest Mushroom. Courtsey: vyperlook.com
This is supposed to be the largest mushroom ever grown. Is it a Plant or something else. It is a Fungi; a different kingdom. The members of this Kingdom range from microscopic moulds and yeast cells to hyphae that grow hidden but exhibit as mush rooms. They are not plants as they have no chlorophyll and cellulose in cell walls. They cannot be animals as they have cell walls. These cell walls are made of a poly-sacharide called chitin which happen to be present in some animals such as in the exo-skeleton of Arthropoda. Structure Most fungi are similar to icebergs as a greater part of it cannot be see. The mushroom canopies that we see are the fruiting bodies or sporophytes developed for asexual reproduction. The main body is made up of fine threads called hyphae, that remain hidden to the naked eye. This part is called the mycelium.  Fig.2. Diagram of septate hyphae. .(highly magnified)  Although in some fungi the hyphae are divided into compartments with a nucleus in each, in some fungi the whole filament looks a single cell with several nuclei. Fungi live on some kind of food matter. They cannot synthesize or engulf food as some protists do. They secrete enzymes to digest the food externally and absorb the nutrition. Fig.3. Non non septate hyphae. (Coenocytic) Moulds. Penicillin is a very well known antibiotic. Alexander Fleming obtained this from a mould that had the same name.These grow on moist bread and other food substances as invisible thread like structures called hyphae What are the powdery stuff here? Reproduction.
After the mycelium has grown for a few days they produce the reproductive structures. They are called sporangia.
Yeast Saccharomyces.. This is a uni cellular fungi. This had been of immense use to man from ancient times. It makes the dough rise in making bread.  Fig 6. Yeast producing buds. Yeast is typically 3-4μm
Normal building materials and furnishings provide ample nutrition for many species of molds, but they can grow and amplify indoors only when there i s an adequate supply of moisture. Courtsey. Pubmed. Supplements
From the New Scientist of 13th Feb 1916 Paul Stamets says “We are sitting on a mould mine.”  Courtsey: Fungi Perfecti. A bracket fungus off birch trees can arry fire. When this is boiled and stretched you get a fabric . At present only the people in Tansylvania do this. As they are in the shape of a basket people make hats out of it. The magic mushroom ( psilocybin) had been able to stop a stutter he had been having. Scientist have found that it can stimulate the growth of neurons. Us Defence department has found pharmaceuticals that can act on dangerous viruses and bacteria. Bees such the juice of some fungi probably to de toxify the poisons they get from insecticides and herbicides.
 Comparing Microbes
(image courtesy of Jeff Benn) Another example is the 'Fairy Ring Toadstool' (Its scientific name is Marasmius oreades). This, in contrast to the Clouded Agaric, grows on grassy expanses such as lawns and golf courses. The fungus can be traced by the rings of dark green grass, with the mushrooms fruiting on the outer edge of the ring. The growth of the ring can be traced year on year. If there are no barriers, rings may grow outwards at up to 20 cm per year. This is a fungus which fruits early in the year, in the spring.
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Living things.
Living Things Ferns and Chicks are easy to recognise as living things while stones and ice are dead as door nails. But when it comes to micro organisms, the task is not that simple. here is a lady by the name Mrs.C.Green, who can help you. Let us take the letters of her name. M = Movement. Non living things too can move. Clouds can move, Planes can fly. These things do not move on their own will. Clouds are pushed by the wind a plane has to be piloted In the case of plants although the movements are limited due to the presence of cell walls they show growth movements. Normal shoots grow towards light while the roots grow towards water. In certain climbers the tendrils coil round a stick. R = Respiration. This is a process similar to burning. Inside the cells, the food is burnt in a special way, at a low temperature, to release energy. Normally sugar is burnt using oxygen producing carbon dioxide and water. S= Sensitivity. The organisms can respond to changes in the environment. A TV can be sensitive to a remote control but this is not the same as responding to a stimulus. TV cannot decide what it has to do. It can only perform a task that has been programmed. In the case of a dog if you hit it we cannot say how it will respond. It may bark, run away or bite you. It can decide what’s to be done. C = Cells. These are the building blocks of living things. Every cell of an organism has a copy of the DNA code of that individual. G = Growth. Growth here does not mean mere increase in size. Crystals can grow , which is due to the deposition of matter on the surface. Growth in living things result in the formation of body matter which occurs within the calls. When cells attain a certain size they divide by a process called cell division. Growth is the result of increasing the number of cells. R= Respiration. This is the method of obtaining energy by the organisms. The food such as glucose is oxidised at a low temperature with the help of enzymes. There are two modes of respiration. Aerobic and anaerobic. In anaerobic respiration other substances are used instead of oxygen. E = Excretion. This is the process of removing waste matter formed inside the cells. They include mainly urine (Or ammonia) , water and carbon dioxide in the case of animals. N= Nutrition.
Taking in of substances for the purpose of growth and respiration is nutrition. Plants take in CO2 from the air water and mineral salts from the soil and synthesize food using light energy. (Photosynthesis) Animals fungi and most bacterie obtain food from other living organisms.
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Mysteries.
 An octopus sat on her eggs for years. A hen broods on her eggs for 21 days.Can you imagine any creature sitting on her eggs for 53 months; 1590 days?An octopus mother had just done that from may 2007 September 2011. Bruce Robinson and his team has observed this by sending a submersible several times . They found Graneledone boreopacifica clinging on to a cluster of about 160 olive sized eggs at a depth of 1400 m. in California’s Monterey Bay.According to them she may never had eaten or moved out during this period. This is a mystery for the biologists. They think that the near freezing temperature may have ceased all metabolic activity.More about Octopuses.“ With its eight prehensile arms lined with suckers, camera-like eyes, elaborate repertoire of camouflage tricks and spooky intelligence, the octopus is like no other creature on Earth. The independent computing power of the arms, which can execute cognitive tasks even when dismembered, have made octopuses an object of study for neurobiologists. Alison Abbott Nature.
An Octopus has 8 arms. Three hearts. A tiny piece of bone as skull and a rudiment of a shell. Arms contain suckers of varying size all along. These are capable of grasping, feeling and tasting, Each is capable of exerting a force of about 150 N. At the base of an arm is the mouth. Food can pass from sucker to sucker. It can change the colour and texture of the skin in a split second. What colour is blood? Red ? The blood of an octopus is blue. They use ' jet propulsion' for movement in water. Behaviour They often escape from aquariums as they are capable of creeping through small holes. They seem to be as intelligent as some mammals. They remember people. If they don’t like a person it can eject a stream of water from the funnel at the person. Reference: The Soul of an Octopus. by Sy Montgomery. |
Digestive system
 The first attack, on whatever we eat, comes at the very start in the oral cavity / buccal cavity. The 32 teeth will not spare a single hard morsel of food. Buccal cavity.(Mouth)
Digestion is a two prong attack. 1. Physical - Pulverizes the food to obtain a bigger surface area. 2. Chemical- Converts the insoluble food to soluble forms. (Bigger molecules are broken down to smaller ones.) Example:- Starch to Glucose. These changes occur without the reagents (enzynes) being used up. So Enzymes are organic catalysts.
. Small Intestine. 1. Duodenum. 2. Jejunum, 3. Ileum.
Absorption Glucose and amino acids straight away pass on to the blood capillaries in the villi. These capillaries form the hepatic portal vein which takes the food into the liver. The liver may store or alter any of the digestive products. Some of the fatty acids and glycerol may enter the blood capillaries, but a large proportion enters the epithelium to be converted back to lipids. These products then pass on to lacteals. The fluid in these joins the lymphatic system which will join the blood stream later. Large Intestine. (Colon)
 
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