Human Karyotype Pedigree Analysis

ADVERTISEMENT

Name   _ ________________________________Period   _ _______Lab   #   _ ________   D ate   _ ________________  
Human Karyotype & Pedigree Analysis
Introduction:
Each   s pecies   h as   a   c haracteristic   n umber   o f   c hromosomes;   f or   e xample,   c orn   c ells   h ave   2 0  
chromosomes,   m ouse   c ells   h ave   4 0   c hromosomes,   a nd   h uman   c ells   h ave   4 6   c hromosomes.   I n   o rder   t o   v iew  
the   c hromosomes   s o   t hat   t hey   m ay   b e   c ounted,   a   c ell   w ill   b e   a llowed   t o   r eproduce   a nd   c olchicine   i s   a dded  
to   s top   t he   c ell   d ivision   d uring   m etaphase.   T he   r esulting   c ells   a re   p laced   i n   a   h ypotonic   s olution   t hat   c auses  
the   c ell   m embranes   t o   r upture.   T he   c hromosomes   a re   s tained   a nd   p hotographed.   T he   c hromosomes   m ay  
then   b e   c ut   o ut   o f   t he   p hotograph   a nd   a rranged   b y   h omologous   p airs.   T he   r esulting   d isplay   i s   c alled   a  
karyotype.    
Part 1: Typical Karyotype
The   n ormal   h uman   k aryotype   i s   c omposed   o f   s even   g roups   o f   c hromosomes   ( A   –   G )   p lus   t he   s ex  
chromosomes   ( X   a nd   Y ).     T he   c hromosomes   a re   g rouped   a ccording   t o   s ize,   p osition   o f   t he   c entromere   a nd  
the   c haracteristic   b anding   p attern.     T he   f irst   s even   g roups   a re   c alled   t he   a utosomes   w hile   t he   l arger   X   a nd  
smaller   Y   c hromosomes   a re   c alled   t he   s ex   c hromosomes.    
Observe   t he   n ormal   h uman   k aryotype   c hart   f ound   i n   F IGURE   I .    
Figure I - Human Karyotype Chart
 
1.
What   i s   t he   t otal   n umber   o f    
 
chromosomes   f ound   i n   t his   c ell?        
 
 
2.
How   m any   a utosomal   c hromosome    
 
pairs   a re   v isible   i n   t he   k aryotype?      
 
 
3.
What   i s   t he   s ex   o f   t he   i ndividual?  
 
 
4.
Which   p air   i s   n ot   g iven   a   n umber?     W hy?  
 
 
 
 
5. In   m any   k aryotype   c harts,   t he   X   c hromosome   i s   p laced   i n   t he   C   g roup   a nd   t he    
Y   c hromosome   a t   t he   e nd   o f   r ow   4 .     S uggest   a   r eason   w hy   t his   i s   d one.  
 
 
 
6. Could   2   i ndividuals   h ave   t he   s ame   k aryotype?     E xplain   w hy   o r   w hy   n ot.  
 

ADVERTISEMENT

00 votes

Related Articles

Related forms

Related Categories

Parent category: Education
Go
Page of 4