Chromosomes Section 8 1 Chromosome Structure INTRODUCTION 1

Chromosomes Section 8. 1

Chromosome Structure • INTRODUCTION 1. Chromosomes are the structures that contain the genetic material 1. They are complexes of DNA and proteins (_______) 1. The genome comprises all the genetic material that an organism possesses – In bacteria, it is typically a single circular chromosome – In eukaryotes, it refers to one complete set of nuclear chromosomes Note: • _________________________

Chromosome Structure Note: The less tightly coiled DNA-protein complex called ________. -This is the form that DNA is in between cell division.

Chromosome Structure 2 Parts: 1) ______: two identical parts of a chromosome 2) ______: Joins chromatids together

Karyrotype • • • Defined: _______________ – Help identify sex & chromosome defects Size of final pair identifies sex – Same size: XX = female – Different size: XY = male Normal human will have 46 chromosomes Types of Chromosomes • __________ • chromosomes that determine the sex of an organism (X and Y chromosome in humans) • __________ • All of the other chromosomes with the organism (chromosomes 1 -22 in humans)

Diploid Cell • Diploid Cells = Cells with the full set of chromosomes – Paired chromosomes • Half of our chromosomes come from each parent (23 from each parent) • ____(non-sex) cells are diploid • Created by mitosis • Ex: ____________

Haploid Cells • Haploid Cells = Cells with ½ the total number of chromosomes • ______(sex cells) are the only haploid cells – Ex: _______ • Created by meiosis – Chromosome number reduced by ½ • How do humans get 46 chromosomes? Haploid sperm cell (23) + Haploid egg cell (23) = Diploid zygote (46)