BIOLOGICAL SCIENCES

By:

MARIA KRISIA FAE DELOS REYES DE ASIS, BSN-RN

Please bring out any piece of paper and prepare for a quiz..

GOOD LUCK!

QUESTION:

What is the CAT FAMILY?

QUESTION:

What is the DOG FAMILY?

QUESTION:

What is the BEAR FAMILY?

QUESTION:

Who was the first person to use the term “cell”?

QUESTION:

What is the study of cells?

QUESTION:

What is the nucleic acid that contains the hereditary information for cells? (shortcut or full name)

QUESTION:

What is the semifluid that fills the cells and enclosed by the plasma membrane?

QUESTION:

What is the command center of the Eukaryotic cell?

QUESTION:

What is the packaging center of the cell?

QUESTION:

What are the powerhouses of the cell?

QUESTION:

What converts light energy into the sugar glucose by means of photosynthesis?

QUESTION:

What functions as the cell’s recycling center and garbage disposal?

QUESTION:

What stores the blue, red, and purple pigments that give certain flowers their colors?

QUESTION:

What provides plants with rigidity and support for stems, leaves, and flowers?

CELL CYCLE-is vital for growth; for repair and replacement of damaged or worn out cells; and for asexual reproduction

-An orderly set of stages that take place between the time a eukaryotic cell divides and its daughter cells divide

- DNA replication occurs

CELL CYCLE- The life cycle of eukaryotic cells, or cells containing a nucleus, is a continuous process typically divided into three phases for ease of understanding: INTERPHASE, MITOSIS, and CYTOKINESIS

CELL CYCLEINTERPHASE-Where most of the cell cycle is spent-A time when the cell performs its usual functions, depending on the location in the body

+ G0 stage – stage wherein cells to not complete the cell cycle and is in permanent arrest

CELL CYCLE

G1 STAGE

-Stage before DNA replication-The cell doubles its organelles (mitochondria and ribosomes) and accumulates materials for DNA synthesis

CELL CYCLE

S STAGE

-DNA synthesis/replication occurs resulting in duplicated chromosomes-At the beginning, each chromosome is composed of ONE DNA double helix (CHROMATID)-At the end, each chromosome has two identical double helix molecules

CELL CYCLE

G2 STAGE

-Stage from the completion of DNA replication to the onset of mitosis-The cell synthesizes protein that will assist in cell division

CELL CYCLE

MITOTIC STAGE

-process in which a cell’s nucleus replicates and divides in preparation for division of the cell -results in two cells that are genetically identical-Occurs in 5 steps: PROPHASE, PROMETAPHASE, METAPHASE, ANAPHASE, and TELOPHASE

CELL CYCLE

Prophase

-the replicated, linked DNA strands slowly wrap around proteins that coil and condense into two short, thick, rod-like structures called chromatids, attached by the centromere -Two structures called centrioles, both located on one side of the nucleus, separate and move toward opposite poles of the cell

CELL CYCLE

Prophase

-As the centrioles move apart, they begin to radiate thin, hollow, proteins called microtubules

-The microtubules arrange themselves in the shape of a football or spindle that spans the area of the cell

CELL CYCLE

Prometaphase

-marked by the disintegration of the nuclear membrane

-As the spindle forms, the nuclear membrane breaks down into tiny sacs or vesicles that are dispersed in the cytoplasm

CELL CYCLE

Prometaphase

-The spindle fibers attach to the chromatids near the centromeres, and tug and push the chromatids so that they line up in the equatorial plane of the cell halfway between the poles

-one chromatid faces one pole of the cell, and its linked partner faces the opposite pole

CELL CYCLE

Metaphase

-exactly half of the chromatids face one pole, and the other half face the other pole= METAPHASE PLATE

CELL CYCLE

Anaphase

-begins when the centromeres split, separating the identical chromatids into single chromosomes, which then move along the spindle fibers to opposite poles of the cell

-At the end, two identical groups of single chromosomes congregate at opposite poles of the cell

CELL CYCLE

Telophase

-The final stage of mitosis

-a new nuclear membrane forms around each new group of chromosomes

-The spindle fibers break down and the newly formed chromosomes begin to unwind

CELL CYCLE

CYTOKINETIC STAGE

-final phase of the cell cycle-The timing of cytokinesis varies depending on the cell type-the cell’s cytoplasm separates in half, with each half containing one nucleus-Two identical daughter cells are produced