Understanding Chromosomes: Formation, Types, and Genetic Implications in Human Cells
This resource explores the fundamental components and functions of chromosomes in human biology. It covers the formation of new cells, types of cells (gametes and somatic), eukaryotic reproduction, and the structure of chromosomes, including homologous pairs and the concepts of diploid and haploid cells. Detailed insights into autosomes and sex chromosomes, as well as chromosomal abnormalities and karyotyping, aid in understanding genetic variations and defects. The information serves as a valuable reference for students of academic biology regarding chromosomal structure and function.
Understanding Chromosomes: Formation, Types, and Genetic Implications in Human Cells
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Presentation Transcript
Chromosomes Mrs. MacWilliams Academic Biology
Chromosomes“chromo”=colored; “soma”= body A. Formation of New Cells 1. Human body makes 2 trillion cells per day! B. TYPES OF CELLS: 1. Gametes- reproductive cells (eggs & sperm) 2. Somatic Cell-“body cell” (not reproductive)
C. Eukaryotic Reproduction 1. Gene- segment of DNA that codes for a protein or RNA molecule 2. Chromosomes -Chromatin- DNA + proteins that make up eukaryotic chromosomes -Chromatids- two exact copies of DNA that make up each chromosome. “Sister Chromatids” -Centromere- point at which 2 chromotids attach to form chromosome
One chromosome 2 chromatids One centromere
D. Sets of Chromosomes **Humans have 23 PAIRS (2 sets) of chromosomes (46 chromosomes total) 1. Homologous chromosomes- (homo=same; logous=location) PAIR that are SAME size, shape, and genetic content 2. Diploid- (di=two) somatic cells have two SETS chromosomes (46) 3. Haploid- (hap=half) gametes have one SETof chromosomes (23) (sperm & egg) 4. Zygote- (zygo=union) fertilized egg - egg 23 (haploid) + sperm 23 (haploid) = 46 diploid
E. Types of Chromosome 1. Autosomes-(auto=self; soma=body) CHROMOSOMEnot directly involved with determining GENDER 2. Sex chromosomes- determine gender (humans have X and Y) XX = FEMALE= XY = MALE= http://www.ornl.gov/sci/techresources/Human_Genome/posters/chromosome/index.shtml
F. Change in Chromosomes 1. change in number/structure of chromosomes = genetic abnormality 2. Karyotype- (karyo=nucleus) picture of the chromosomes in a dividing cell (aids in finding genetic defects)
Male karyotype Female karyotype
Karyotype of a Haploid Gamete (Sex Cell) **This cell would either have ONE X chromosome or ONE Y
