..........BLOG.............

Hello Ma'am!!!!!!!!!!!!
This is my blog for last week...............

Hmmmmmmmmmmmmmm..............I'm so tired,tired of reviewing all
the lessons we tuckle for the preparation for the periodical
test,,,,,,,,,I wish I could get a high score............

I learned many things on the third grading in biology,,,,,,,,,,, the skeletal system,,,,integumentary system,,,,,,,,,,,the different hormones and glands
of the body,,,,,,,,the meiosis,,,,,,mitosis,,,,,,,,reproduction of
plants,animals and humans.........

Skeletal System,,,,,,,,serves many important functions; it provides the shape and form for our bodies in addition to supporting, protecting, allowing bodily movement, producing blood for the body, and storing minerals.Its 206 bones form a rigid framework to which the softer tissues and organs of the body are attached.Vital organs are protected by the skeletal system. The brain is protected by the surrounding skull as the heart and lungs are encased by the sternum and rib cage.

Meiosis is the type of cell division by which germ cells (eggs and sperm) are produced. Meiosis involves a reduction in the amount of genetic material.

Meiosis comprises two successive nuclear divisions with only one round of DNA replication.
Four stages can be described for each nuclear division.

* Interphase: Before meiosis begins, genetic material is duplicated.
* First division of meiosis
o Prophase 1: Duplicated chromatin condenses. Each chromosome consists of two, closely associated sister chromatids. Crossing-over can occur during the latter part of this stage.
o Metaphase 1: Homologous chromosomes align at the equatorial plate.
o Anaphase 1: Homologous pairs separate with sister chromatids remaining together.
o Telophase 1: Two daughter cells are formed with each daughter containing only one chromosome of the homologous pair.

* Second division of meiosis: Gamete formation
o Prophase 2: DNA does not replicate.
o Metaphase 2: Chromosomes align at the equatorial plate.
o Anaphase 2: Centromeres divide and sister chromatids migrate separately to each pole.
o Telophase 2: Cell division is complete. Four haploid daughter cells are obtained.

One parent cell produces four daughter cells. Daughter cells have half the number of chromosomes found in the original parent cell and with crossing over, are genetically different........

That's all...............