Presentation on theme: "CELLS AND HEREDITY. Introduction November 30, 2010 New Vocabulary List – back of spiral –Title of new list – Heredity –DNA -- a molecule found in cells."— Presentation transcript:
CELLS AND HEREDITY
November 30, 2010 New Vocabulary List – back of spiral –Title of new list – Heredity –DNA -- a molecule found in cells that contains all the instructions for making new cells. –CHROMOSOME --found inside the nucleus of a cell, this structure contains the DNA –MITOSIS --occurs in eukaryotic cells, and is a process of cell division that forms two new nuclei, each of which has the same number of chromosomes.
Vocabulary Heredity -- The passing of traits from parents to offspring Genetics -- the study of how traits are passes on, or inherited.
Vocabulary (Heredity List) Prophase – the first phase of mitosis, when the nuclear membrane disappears. Metaphase – the second phase of mitosis, when replicated chromosomes line up in the middle of the cell. Anaphase – the third phase of mitosis, when the chromatids are pulled to opposite sides of the cell by spindle fibers Telophase – the fourth phase of mitosis, when the nuclear membranes reform, and the cell membrane starts to pinch in to divide the cells.
Vocabulary Interphase – Before mitosis begins, chromosomes are copied. Cytokinesis – after mitosis ends -- the division of cytoplasm of a cell. Chromatid - a pair of identical DNA molecules after DNA replication, joined at the centromere. Centriole – paired cylindrical organelles, arranged at right angles to each other, located at the center of the spindle fibers.
Single Cell and Multi-Cell Reproduction
Prokaryotes Single-celled organisms –Bacteria –archaea Defined as having no nucleus or membrane around the organelles Most have cell walls Contain a single circular chromosome in the nucleoid region Divide through binary fission –Cell splits into two parts –Each cell has a copy of the DNA formed about 3.5 billion years ago
Eukaryotes The cells of protozoa, higher plants and animals highly structured -- complex Tend to be larger than the cells of bacteria Cell division is in three stages –Interphase –Mitosis –cytokinesis See Animation
The Cell Cycle This is how a eukaryotic cell divides and replicates Cells appear to be dividing at times, and then resting between divisions Interphase is when a cell appears to be restingbut many important activities take place at this time. See AnimationSee Video