HAPPY NEW YEAR

Wishing all my reader from the following countries a HAPPY NEW YEAR! 

May the year bring you fresh energy and excitements in all your endeavors. Stay strong and remain positive. There is always light at the end of the tunnel. I hope you find that light this coming year. I will keep you all in my prayers. 

PEACE BE UPON YOU AND YOUR COUNTRIES!

Afghanistan Bahrain Canada Australia Bangladesh Colombia Barbados Dominican Republic Ecuador Germany Egypt Ghana Ethiopia Guatemala India Jamaica Lebanon Indonesia Japan Ireland Jordan Italy Malaysia Nepal Oman Maldives Netherlands Mexico New Zealand Nigeria Pakistan Saudi Arabia Peru Serbia Philippines Singapore Puerto Rico Slovakia South Africa South Korea Spain Sri Lanka Taiwan United Arab Emirates Vietnam Tanzania United Kingdom Thailand United States Trinidad & Tobago Turks & Caicos Islands Zambia Zimbabwe

KEY DEFINITIONS FOR CELL DIVISION

What is a gene?

 It is the basic unit of heredity and it codes for a specific trait.

What is a genome?

 It is the total hereditary endowment of DNA of a cell or organism

What is a locus (plural loci)?

 It is the specific location of a gene on a chromosome

What is a somatic cell?

 It consists of all the body cells except reproductive cells.

What is a gamete?

 It is the reproductive cells  (sperm and egg)

What is a chromosome?

 It is the elongate cellular structure composed of DNA and protein. They are the vehicles which carry DNA in cells.

What is a homologous chromosome?

 It is a chromosome of the same size and shape which carry the same type of genes.

What is a diploid (2n)?

 It is the cellular condition where each chromosome type is represented by two homologous chromosomes.

What is a haploid (n)?

 It is the cellular condition where each chromosome type is represented by only one chromosome.

What is a chromatid?

 It is one of two duplicated chromosomes connected at the centromere.

What is a centromere?

 It is the region of chromosome where microtubules attach during mitosis and meiosis.

What is an allele? 

It is an alternate form of the same gene. For example, there are two genes that control height, that is, one for shortness and the other for tallness.

What is a homozygous individual? 

It is the condition where an individual has two identical alleles for a given gene. 

What is a heterozygous individual?

 It is the condition where an individual has two different alleles for a given gene.

What is a genotype? -

It is the genetic makeup of an organism?

What is a phenotype?

It is the expressed traits of an organism or the outward manifestation of the genes. 

There are two types of cell divisions. They are mitosis and meiosis?

• Mitosis results in two diploid daughter cells.
• Meiosis results in four haploid daughter cells.

We will discuss more details of cell division in the next post.

THE ENDOCRINE SYSTEM

An endocrine gland is a gland without ducts. The secretions are released directly into the blood. The endocrine glands secrete hormones that regulate various metabolic activities in the body.
Here is a good diagram of the endocrine system. Click here. You can be given a diagram like this and you could be asked to identify the various glands.

Hypothalamus: The hypothalamus produces eight (8) hormones. Some of the hormones stimulate the pituitary gland to produce other hormones.

1. Thyrotropin-releasing hormone - This acts on the pituitary to release thyroid stimulating hormone (TSH)
2. Growth hormone-releasing hormone-This acts on the pituitary to release growth hormone (GH)
3. Gonadotropin-releasing hormone -This acts on the pituitary to release gonadotropins, namely, Follicle stimulating hormone (FSH) and Luteinizing hormone (LH).
4. Corticotropin-releasing hormone -This acts on the pituitary to release adrenocorticotropic hormone.
5. Oxytocin -This causes uterine contractions and also helps with secretion of the breast milk during lactation.
6. Dopamine - It is a neuroendocrine transmitter. Acts as a neuro-transmitter and also stimulates the release of othe hormones.
7. Vasopressin (Antidiuretic hormone -ADH) - Acts on the kidneys to prevent the lost of water via the urine.
8. Somatostatin - It inhibits the release of growth hormone.

Pituitary gland: Has an anterior (hormone-producing glandular) portion and a posterior (neural) portion which is an extension of the hypothalamus.  Two hormones ( Oxytocin and ADH) produced by the hypothalamus are stored in the posterior pituitary later release.

Four of the six pituitary hormones are tropic hormones. They regulate the function of other endocrine glands.Here are the hormones produced by the anterior portion:

1.  Growth hormone (GH): It stimulates growth of all body tissues but especially skeletal muscle and bone. GH mobilizes fats, stimulates protein synthesis, and inhibits glucose uptake and metabolism. Over production can lead to gigantism while underproduction can lead to dwarfism.

2. Thyroid-stimulating hormone (TSH): This promotes normal development and activity of the thyroid gland. 

3. Adrenocorticotropic hormone (ACTH): This stimulates the adrenal cortex to release  corticosteroids. 

4. The gonadotropins (follicle-stimulating hormone (FSH) and luteinizing hormone (LH)): These regulate the functions of the gonads in both sexes. 

     (a) FSH stimulates sex cell production.  

     (b) LH stimulates gonadal hormone production. 

5. Prolactin (PRL): This promotes milk production in humans females. 

The posterior portion stores and releases two hypothalamic hormones:

1. Oxytocin: This stimulates powerful uterine contractions during labor and delivery of babies. It also causes milk ejection in nursing women. 

2. Antidiuretic hormone (ADH): This stimulates the kidney tubules to reabsorb and conserve water. This results in the production of small volumes of highly concentrated urine and decreased plasma osmolality. Underproduction leads to a condition called diabetes insipidus, where the affected person passes a lot of diluted urine.

Thyroid gland

It produces the thyroid hormone (TH), which includes thyroxine (T4) and triiodothyronine (T3). It increases the rate of cellular metabolism. 

Calcitonin, is produced by the parafollicular cells of the thyroid gland. It decreases the blood calcium levels.

Parathyroid glands

It secretes parathyroid hormone (PTH), which causes an increase in blood calcium levels.

Pancreas

The pancreas is both an exocrine and an endocrine gland. Exocrine means that it has ducts. The endocrine portion (islets of langerhans) releases insulin and glucagon. It also releases smaller amounts of other hormones to the blood.

Glucagon, released by alpha (α) cells - It increases the glucose level in the blood.

Insulin is released by beta (β) cells - It reduces the glucose level in the blood. It increases the rate of glucose uptake and metabolism by most body cells. 

Gonads

The ovaries of the female release two main hormones - estrogens and progesterone. Estrogens stimulate maturation of the female reproductive system and development of the secondary sexual characteristics. Progesterone works with estrogens in establishing the menstrual cycle.

The testes of the male produce testosterone. It promotes maturation of the male reproductive organs, development of secondary sex characteristics, and production of sperm by the testes.

Pineal gland

The pineal gland produces the hormone  melatonin, which influences daily rhythms such as sleep and wake patterns.

Thymus 
It is an important organ of the immune system during the developmental stages of life. It vanished by the time of birth. The T-cells mature here.

HOLIDAY BLESSINGS JUST FOR YOU

As you celebrate a new chapter in your life during this Christmas,

May the joy of the Lord be your portion.

May you find an uncommon favor with the Lord,

And may your territories be enlarged beyond your understanding.

The goodness and mercies of the Lord is upon you

And you will enjoy the days of your life.

You shall lack nothing in the coming years because His eyes are upon you.

Your pockets will never run dry. It shall run over.

Your are the apple of the Lord’s eyes and He will guide you

As you make your journey in life.

The Lord is faithful. He will establish you and protect you from the evil one.

Enjoy this Christmas and the many, many years to come!

VOCABULARY SENTENCES

Here is a link to review vocabulary sentences.

VOCABULARY DRILL - 2

Learn some new definitions today. Click on Definitions

IMPORTANT FORMULAS FOR MOTION

There are some few motion formulas that you should know for the test.

1. Distance = speed x time 

2. Work = Force x distance

3. acceleration = change in velocity  =  Final velocity - Initial velocity  

                            change in time              Final time - Initial time

                            

Positive slope means the car is accelerating, that is the velocity is increasing with time. Zero slope means the velocity is constant (that is, not changing with time), and negative slope means the car is slowing down (that is, the velocity is decreasing with time)

Also, you must know the standard international (SI) units of the following:

1. Work -------------Joules (J)

2. Force ------------- Newtons (N)

3. Velocity ---------- meters per second (m/s)

4. Time ------------ seconds

NEWTOW'S LAWS OF MOTION

We will study some physics today. Horray! You need to know some basic physics for the test. We will consider some of the laws of motion and their applications.

NEWTOW'S LAWS OF MOTION

1. A body at rest will remain at rest or if it is in motion, it will continue to move unless an opposing force acts on it. This law explains why if you leave a book on a table, it will be there forever unless somebody moves it. It also explains why somebody is thrown out of a moving car or bus live a projectile when the vehicle comes to a sudden stop. You move at the same speed of the vehicle you continue to move with this speed until the windshield stops you (opposing force)

2. The force on an object is directly proportional to its acceleration and the mass. The acceleration is inversely proportional to the mass. In others words, as the acceleration and the mass increase, the force increases. As the mass increases, the acceleration decreases and vice versa.

Force = Mass x Acceleration 

3. Action and reaction forces are equal but in opposite directions. What does this mean? If you push a wall, you exert an act force on it. The wall pushes you back with the same force (reaction force) which is in the opposite direction. The same thing happens with you standing on the ground.

QUANTITIES

There are two types of quantities used in science.

1. Scalar quantity: This quantity has only magnitude. Example: mass, time, density, volume, distance, speed, etc. Only the magnitude or size matters! For example, traveling 2 miles is distance or traveling at the speed of 2 mph or 2 km/hr.

2. Vector quantity: This quantity has both magnitude and direction. For example, displacement, velocity, weight, force, etc. The direction has to be specified.  For example, traveling 2 miles north is displacement or traveling at the velocity of 2 mph or 2 km/hr west.

CLASSIFICATION OF ORGANISMS

The classification of living things is called "Taxonomy." Living organisms are classified into 

• Domains - This includes Archea, Eubacteria, Eukaryote. Domains are classified into five kingdoms.
• Kingdom is then split into smaller groups, called Phyla (singular is Phylum).
• Phylum is split into smaller groups called Classes.
• Class is split into Orders, 
• Order is split into Families
• Family is split into Genera (singular is Genus).
• Genus is split into Species.
• Species is a single organism, not a group.

This results in eight types of groups in order from largest to smallest as shown above. This is known as the Linnaean classification system.

Eubacteria are bacteria, made up of small cells, which differ in appearance from the organisms in the above kingdoms. They lack a nucleus and cell organelles. They have cell walls made of peptidoglycan.

Archae (or Archaebacteria) are bacteria which live in extreme environments, such as salt lakes or hot, acidic springs. These bacteria have unique properties and features such as unusual lipids that are not found in any other organism. Their cell walls lack peptidoglycan.

The five kingdoms:

• Animalia (Animal) - This includes sponges, worms, insects, fish, amphibians, reptiles, birds, and mammals.
• Plantae (Plant) -This includes mosses, ferns, woody and non-woody flowering plants.
• Fungi -This includes fungus, molds, mushrooms, yeasts, mildews, and smuts.
• Protist - This includes protozoans and algae of various types.
• Monera - This includes bacteria, blue-green algae (cyanobacteria), and spirochetes.

Binomial nomenclature is used to name an organism. The first word beginning with a capital is the genus of the organism and the second word beginning with lower-case letter is the species of the organism. The scientific name can be also abbreviated, where the genus is shortened to only its first letter followed by a period. For example, Lepus europaeus can be written as L. europaeus. 

                   Homo sapien can be written as H. sapien

What are Eukaryotes? 

They are cells that are complex in structure, with nuclei and membrane-bound organelles. Examples are the animal and plant cells.

What are  Prokaryotes? 

Prokaryotes are the smallest and simplest type of cells, without a true nucleus and no membrane-bound organelles.

Examples are the bacteria and viruses.

VOCABULARY DRILL

I hope so far you have enjoyed practicing on the vocabulary exercises. You must try to review them as frequently as possible to get them into your long term memory.

Here are links to more vocabulary drills:

1. Definitions

2. Definitions

3. Vocabulary sentences

4. Vocabulary sentences

5. Antonyms (Opposites)

6. Parts of speech

7. Correct Spelling

VOCABULARY GAME

Here is a link to the website of Encyclopedia Britannica. It has vocabulary exercise that is time. You are given the word and you have about 10 seconds to choose the correct synonym from about five options. The faster you answer the questions, the more points you get. This is a very interesting way to learn vocabulary - a vocabulary game. There are over 1000 words to practice on. There are 10 words per game.

Click this link: Vocabulary Game

Here is a link to a similar word game on the human organs. Have fun!

LYMPHATIC SYSTEM

The lymphatic system is involved with the clearing of infectious agents from the body. It transports the lymph which is the clear fluid originating from the plasma (liquid portion of blood). 

Functions

• Lymph drains interstitial fluid
• Transports dietary lipids 
•  Facilitates immune responses.

The plasma filters out of the capillaries and drains into lymphatic vessels to become lymph. It also transports fat. The lymph flows in the lymphatic vessels, lymphatic tissue and red bone marrow. The content of lymph is the same as interstitial fluid (the fluid around tissue cells). The Lymph eventually drains into venous blood via the right atrium.

What are the primary lymphatic organs? 

These are the sites where the lymphoid cells (T-LYMPHOCYTES and B-LYMPHOCYTES) are produced. It includes:

• Bone marrow
• Thymus

What are secondary lymphatic organs?

Secondary lymphoid tissues are arranged as a series of filters that monitor the contents of the extra-cellular fluids (lymph, interstitial fluid and blood). Secondary lymphoid tissues are also where lymphocytes are activated.

These include: 

• lymph nodes: The lymph is filtered by lymph nodes. These are encapsulated lymphoid tissue. There are about 100-200 lymph nodes, which mostly occur in the neck, thorax, abdomen and pelvis. They contain B-lymphocytes (cells) and T-lymphocytes (cells), which mostly enter the nodes via the blood stream. It also contains macrophages. 
• Mucosa Associated Lymphoid Tissue (MALT): These are non-encapsulated lymphoid aggregations found close to moist epithelial surfaces such as the mucous membranes of the digestive, respiratory and reproductive systems. They respond to any bacteria or micro-organisms that do get through the epithelia. The activated B-cells in these areas can develop into plasma cells, which then produce antibodies. They filter tissue fluid.  This makes up 85% of lymphoid tissue in the mucosa. They are usually small (around 1 millimeter in diameter), with the exception of the tonsils, peyers patches and the appendix.
• Tonsils are large partially-encapsulated masses of lymphoid tissue, found in the walls of the pharynx and nasopharynx, and at the base of the tongue. 
• Peyer's patches are large masses of confluent lymphoid follicles, found in the walls of the ileum (small intestine).
•  Spleen: The blood is filtered by the spleen, an encapsulated lymphoid tissue. This is the body's largest lymphatic organ. 

Functions of the spleen: 

• It is important for antibody production
• Facilitates immune responses to blood borne antigens 
•  It eliminates worn-out blood cells and platelets.

WHAT IS BOTANY?

What is botany?
It is one of the branches of biology that deals with the study of plants.

• What kinds of plants?
• How they live and grow.
• How they respond to their environment.
• The diseases they are susceptible to, and how they can be cured.
• How they influence our everyday lives.

Branches of botany

There are many branches of botany. This includes:

• Taxonomy: Deals with the classification of plants
• Morphology: Studies the form and structure of plants (anatomy, cytology, embryology)
• Physiology: Concerned with the life processes of plants and functions of the different organs and tissues.
• Pathology: Deals with the diseases of plants.
• Ecology: Deals with the relations of plants to their surroundings
• Paleobotany: Also known as fossil botany, deals with plants of past geological periods.
• Plant Genetics: Deals with the study of heredity in plants.

Other areas of intensive study include:

• Bacteriology: Study of bacteria
• Mycology: Study of fungi
• Algology: Study of algae
• Bryology: Study of mosses and liverworts

AN ODE TO PLANTS

Today, I am sharing with you a poem I just wrote when I was thinking about nature. I was inspire to write this while reading a book about plants. I hope you enjoy reading it and SAVE the PLANTS.

From the dawn of history you ministered to our needs;
Thou ancient of days, present in the beginning of life;
For your love, you furnish us with food,
Clothing and shelter we lack not.
In you we have life, for the air we breath is enriched by your oxygen.

For without you, we perish.
Oh how, you purify the air we breath!
Our waste, carbon dioxide, is your delicacy. 
Mills are powered by thee, 
Your raw materials are made into products.
Wages are earned because of you.

For your love, Columbus set off in search of thee;
Your spices are worth more than you think.
What would Henry Hudson have done without you?
From the Hudson River Basin to Eastern Canada, he marveled at your beauty.
Wars have been fought because of you,
For you are priceless and worth keeping.


You furnish the settings and beautify the surroundings;
Your fragrance perfuse our minds with wonder.
Literature, music and art are inspired by thee.
Thou ancient of days, present in the beginning of life;
We adore thee!

CELL CHEMISTRY

There are three types of substances that life is dependent on. These are carbohydrates, proteins, and lipids (fats).                                                                                                                                                      

1. Carbohydrates: These are used to produce energy for cellular activities.                                          

Types of carbohydrates:                                                                                                                            (a) simple sugars (monosaccharides): One sugar molecule–  Examples: Glucose, fructose and galactose.            

                               

(b) disaccharides: Two monosaccharide joined together.                  

Examples: Lactose = glucose + galactose; Sucrose = glucose + fructose; Maltose = glucose + glucose 

   

Exam hints: Memorize what the disaccharides are composed of.  In order words, what are the end products if you break down or digest a disaccharide.

                                                                                

(c) Complex sugars: Starch, cellulose and glycogen are made up of so many glucose joined together.

Exam hints: Glycogen is the storage form of carbohydrate in animals only . Cellulose is only found in plant cells.

2. Proteins are made up of amino acids. Proteins are the structural building blocks of the organism.

3. Lipids (Fats and oil) are made up of fatty acids and glycerol.

Test for some food substances:

Type of food substance	Test
Starch	Iodine test: Turns blue-black
Simple sugar (Glucose)	(a) Benedicts test: Brick-red coloration (b) Fehlings test: brick red coloration
Protein	Biuret test: light-blue color becomes purple
Lipid	Paper test: Oil stains paper

Exam hints: Memorize the test for the food substances.

VOCABULARY PRACTICE

Here is a link for those who want to practice on vocabulary. You can also create flash cards from this site.

Click here!

VOCABULARY PRACTICE TEST-1

Vocabulary is something that you have to practice everyday to be able to increase your word power for the English test. You can check this link out for some practice test on vocabulary.

1. Practice test 1

2. Practice test 2