WELCOME TO THIS GREAT EDUCATIONAL BLOG

Welcome to my Pre-Nursing Exam Prep blog. I hope it will help you prepare very well for the Pre-NLN entrance exam, popularly known as the PAX exam. This is one of the entrance exams required by some schools for those who want to pursue careers in the nursing field in the USA. I will attempt to break down the review materials into manageable parts so that you can systematically and efficiently prepare for the test with less stress. I will guide you to prepare for the entire content of the test. Hopefully, you will be able to pass after going through these series.


BEST OF LUCK!


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A 12-DAY APPROACH TO ACE THE EXAM

SCIENCE REVIEWThe topics that are generally covered in the test have been grouped into twelve instructional modules below. You will be tested only on the basic concepts of physics, chemistry and biology. Click on science topics and select any of the topics listed in the module to review.

Lesson 1:

Basic structure of atom

Types of tissues

Lesson 2:

Movement of substances across the cell membrane

Acids and bases, pH scale

Carbohydrates, proteins, lipids and nucleic acids

Lesson 3:

Basic structure of the eye

Basic structure of the ear

Nervous system

Lesson 4:

Circulatory system

Introduction to mechanics (motion/forces)

Electrical circuits

Lesson 5:

Balancing chemical equations and writing formulas

Essentials of photosynthesis and respiration

Classifying organic compounds

Magnetism

Electromagnetism

Lesson 6:

Interpretation of graphs and pictograms

Analyzing and making conclusions from experiments

Data analysis

Lesson 7:

Endocrine system

Digestive system

Genitourinary system

Lesson 8:

Reproduction in mammals

Basic parts of a flower

Reproduction in plants (the process of pollination

Genetics

Lesson 9:

Modes of heat transfer

Calculating heat energies and phase diagrams

Temperature conversions (Kelvin, Celsius, Fahrenheit)

Lesson 10:

Gas laws (Boyle, Charles, Gay-Lussac)

Types of energy (Potential, kinetic, etc…..)

Chemical bonds, equilibrium and equilibrium constants

Mixtures, types of solutions, solubility

Lesson 11:

Concepts of the food pyramid, food web and food chain

Light (diffraction, refraction, reflection, dispersion)

Basic concepts on waves

Sound waves

Catalyst and enzymes

Lesson 12:

Symbiosis

Ecology

The Electroscope

Radioactivity and half-life Tropism

Tropism

Thursday, September 25, 2014

BIOLOGY PRACTICE TEST -2

Click below for multiple choice questions.

1. Polymerase chain reaction: Quiz 1

2. Active Transport: Quiz 2

3. Endocytosis/exocytosis: Quiz 3

4. Electron Transport Chain/ATP Production: Quiz 4

5. Electron Transport Chain/ATP Production: Quiz 5

6. Energy Conversion: Quiz 6

7. Photosynthesis: Quiz 7

8. Mitosis: Quiz 8

9. Meiosis: Quiz 9

Wednesday, September 24, 2014

BIOLOGY PRACTICE TEST-1

Click below for multiple choice questions:

1. Catalysis: Quiz 1

2. DNA Structure: Quiz 2

3. DNA Packaging: Quiz 3

4. DNA replication: Quiz 4

5. Transcription: Quiz 5

6. Translation: Quiz 6

7. Polyribosome: Quiz 7

8. Mutation: Quiz 8

9. DNA Repair: Quiz 9

10. Feedback inhibition: Quiz 10

CHEMISTRY PRACTICE QUESTIONS FOR THE DAY

Click below for multiple choice questions.

1. Atomic Structue: Practice Quiz 1

2. Covalent Bond: Practice Quiz 2

3. Ionic Bond: Practice Quiz 3

4. Diffusion: Practice Quiz 4

5. Osmosis: Practice Quiz 5 

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Tuesday, September 23, 2014

PROTEIN SYNTHESIS

STEP 1: Transcription of mRNA from a DNA gene 

  • mRNA stands for messenger RNA. 
  • Protein synthesis begins with the transcription of mRNA from a DNA gene in the nucleus.
  •  The RNAs then migrate from the nucleus into the cytoplasm. 
  • Prior to the beginning of the protein synthesis, all of the component parts are assembled in the ribosomes. 

STEP 2: Initiation

  • In the cytoplasm, protein synthesis is actually initiated by the AUG codon on mRNA. 
  • The AUG codon signals both the interaction of the ribosome with m-RNA and also the tRNA with the anticodons (UAC). The AUG codon is known as the start codon. This is the codon for the amino acid, methionine.
  • The ribosome moves along the mRNA to read the next codon. Once this is done, a tRNA (transfer RNA) with an anticodon approaches the mRNA. This tRNA carries along with it the corresponding amino acid. 
  • The next process is to start growing peptide chain by having amine bond to the carboxyl acid group of methionine in order to elongate the peptide.

STEP 3: Elongation:
Elongation of the peptide begins as various tRNA's read the next codon. The tRNA with the anticodon brings along the corresponding amino acid and a peptide bond is formed between the amino acids. The previous tRNA then returns into the cytoplasm to be reused. The whole process is then repeated.

STEP 4: Elongation and Termination:

  • When the stop signal on mRNA is reached, the protein synthesis is terminated. The stop codons are UAA, UAG, and UGA. The last amino acid is hydrolyzed from its t-RNA.
  • The peptide chain leaves the ribosome. The N-formyl-methionine that was used to initiate the protein synthesis is also hydrolyzed from the completed peptide at this time.
  • The ribosome is now ready to repeat the synthesis several more times.

Wednesday, September 17, 2014

REPRODUCTION IN ANIMALS

Gametes refers to the sperm and the egg. During sexual reproduction, the sperm and the egg unite to form the zygote.
                           Zygote = sperm + egg

Each gamete has half the normal complement of chromosomes, that is, 23 chromosomes in each gamete. The gametes are said to be monoploids (haploid). Fusion results in the full number of chromosomes, 46 (23 pairs). The zygote is referred to as diploid.

In the male, the external reproductive organs are the penis and scrotum.
The internal organs consist of:

  • The testis which contains the seminiferous tubules, where the sperms are produced.
  • The interstitial cells produce testoterone, the male sex hormones.
  • The sperm travels in the epididymis, the coiled tubules, into the vas deferens to the ejaculatory duct to the urethra.
  • Seminal vesicles produce seminal fluid that carries the sperms.
  • Prostate produces prostatic fluid that also carries the sperms.

In the female, the primary reproductive organs are the ovaries, fallopian tubes and uterus.

  • Ovaries produce the eggs and the hormones, estrogen and progesterone.
  • Immature egg is called oocyte.
  • Matured egg is released during ovulation.
  • The egg travels in the fallopian tubes, where it can be fertilized by the sperm. Note that the fertilized egg begins to divide within the tubes within few hours of conception.
  • The lining of the uterus is called the endometrium.
  • The fertilized egg implants in the endometrium.
  • The fetus obtains nourishment via the placenta. Note that, the fetal and maternal blood do not have direct connections. Exchange of nutrients and oxygen is by diffusion.
  • The fetus is connected to the placenta via the umbilical cord.
  • The fetus is covered by the following membranes: amnion and chorion.
  • If there is no fertilization, the uterus sheds its, endometrium. This is referred to as menstruation.

Saturday, September 6, 2014

CONDITIONED REFLEX

Under classical conditioned reflex,  the learned response to the previously neutral stimulus the conditioned response is. For example, the smell of food naturally elicits the feeling of hunger. If a whistle is blown any time food is presented, the sound of the whistle gets associated with the food. It gets to a time when you naturally get hungry any time  the whistle is blown without the physical presence of food. The smell of food is the unconditioned stimulus. The feeling of hunger in response to the the smell is the unconditioned response and the sound of the whistle is the conditioned stimulus. The conditioned response would be feeling hungry when you hear the sound of the whistle.

More examples of conditioned reflex:
1. A child who receives an injection from a person in white coat may associate any white coat with the pain of injection. Any time the child see a person in white coat, he/she suddenly develops fear and avoidance reaction.

2. John and Mercy, who are students, are in love with each other but they attend schools several mile apart. During the spring and summer breaks, they spend time together picking grapes. When they get back to their schools John experiences the feeling of happiness any time he sees grapes.