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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

Tuesday, January 13, 2015

THE PROCESS OF MEIOSIS

Meiosis is a special type of cell division that occurs in the gonads or sex organs.
  • At the end of meiosis, the number of chromosomes is reduced by half. That is, meiosis of diploid cells produces haploid daughter cells.
  • These cells can then function as gametes that can undergo fertilization resulting in the restoration of the diploid number of chromosomes in the zygote.
  • Meiosis and fertilization introduce genetic variation in three ways:

The meiosis consist of two main stages:

  •  Meiosis I: This is made up of four sub-stages: Prophase I, Metaphase I, Anaphase I and Telophase I
  •  Meiosis II: This is made up of four sub-stages: Prophase II, Metaphase II, Anaphase II and Telophase II

You can click on this link to view a diagram on the meitotic process. This will help you to visualize the steps described below.

MEIOSIS I
Prophase I 
  • The chromosomes condense and become visible.
  • The centrioles form and move toward the poles.
  • The nuclear membrane begins to dissolve.
  • The homologs pair up, forming a tetrad. 
  • Each tetrad is comprised of four chromotids - the two homologs, each with their sister chromatid.
  • Genetic material from the homologous chromosomes is randomly swapped. This process is known as crossing over. 
  • Crossing over increases genetic diversity by creating four unique chromatids.

Metaphase I
  • Microtubules grow from the centrioles and attach to the centromeres
  • The tetrads line up along the cell equator.


Anaphase I
  • The centromeres break and homologous chromosomes separate with the sister chromatids are still attached.
  • Cytokinesis begins.
Telophase I
  • The chromosomes may decondense.
  • Cytokinesis reaches completion, creating two haploid daughter cells



MEIOSIS II 
Prophase II
  • Centrioles form and move toward the poles.
  • The nuclear membrane dissolves.
Metaphase II
  • Microtubules grow from the centrioles and attach to the centromeres.
  • The sister chromatids line up along the cell equator.

Anaphase II
  • The centromeres break and sister chromatids separate. 
  • Cytokinesis begins.
Telophase II
  • The chromosomes may decondense.
  • Cytokinesis reaches completion, creating four haploid daughter cells.




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