CHROMOSOMES

What Are Chromosomes? Rod shaped structures made of DNA & Protein DNA – stores the genetic information that cells will use Proteins- sphere shaped structures that the DNA wraps around DNA Proteins

Chromosome Shape Chromatids Centromere

CENTROMERES/ CHROMATIDS Centromere- holds the chromatids together Chromatids- identical sides of the chromosomes Contain same genetic information on both sides

Chromatin Chromososomes are only present during cell division. In between cell division chromosomes are unraveled and called Chromatim

PROKARYOTIC VS EUKARYOTIC CHROMOSOMES Prokaryotic Chromosomes –circular, smaller, NOT in Nucleus Eukaryotic – Larger, rod shaped, in Nucleus

Chromosome Numbers Organism # of chromosome Fruit Fly 8 Carrot & Lettuce 18 Cat 32 Earthworm 36 Human 46 Gorilla 48 Sand Dollar 52 Adder’s Tongue Fern 1262

Which is more complex in terms of functions & intelligence? Adders Tongue Fern Human OR

…OK Bad Example

Two Types of Chromosomes SEX…ok get your minds out of the gutter Determine the gender of the individual Carry few other traits 2 of the 46 chromosomes AUTOSOMES Carry most of the traits that we inherit 44 of the 46 chromosomes

SEX Chromosomes XX = XY =

HOMOLOGOUS CHROMOSOMES A pair of autosomes that have the identical trait for a certain characteristic (eye color). You receive one of the homologous pairs from your father and one homologous pair from your mother Humans have 44 autosomes (minus the 2 sex chromosomes) so they have 22 pairs of homologous autosomes Homologous chromosomes are the same size and shape

KARYOTYPE A picture taken from a microscope of all the chromosomes within a cell. The chromosomes are then arranged in homologous pairs and given a set of numbers

Diploid vs Haploid Cells Description Both sets of homologous chromosomes present Only one of each homologous chromosome present Type of Cell All cells but sex cells (egg or sperm) Only sex cells- Egg or Sperm Abbreviation 2n 1n