Biology Chapter 12 Powerpoint

Incomplete linkage 21 chromosome number polyploidy 22

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: y 22 Chromosomal Inherit Polyploidy Occurs when eukaryotes have more than 2n chromosomes chromosomes Named according to number of complete sets of Named chromosomes chromosomes Major method of speciation in plants ­ Diploid egg of one species joins with diploid pollen of Diploid another species another ­ Result is new tetraploid species that is self-fertile but Result isolated from both “parent” species isolated ­ Some estimate 47% of flowering plants are polyploids Often lethal in higher animals Chromosome Number: Aneuploidy 23 Chromosomal Inherit Monosomy (2n - 1) Diploid individual has only one of a particular Diploid chromosome chromosome Caused by failure of synapsed chromosomes to Caused separate at Anaphase I (nondisjunction) separate Trisomy (2n + 1) occurs when an individual has three of a particular type of chromosome three Diploid individual has three of a particular chromosome Also caused by nondisjunction This usually produces one monosomic daughter cell This and one trisomic daughter cell in meiosis I and Down syndrome is trisomy 21 Nondisjunctio n 24 Trisomy 21 25 Chromosome Number: Abnormal Sex Chromosome Number 26 Chromosomal Inherit Result of inheriting too many or too few X or Result Y chromosomes chromosomes Caused by nondisjunction during oogenesis Caused or spermatogenesis or Turner Syndrome (XO) Female with single X chromosome Short, with broad chest and widely spaced Short, nipples nipples Can be of normal intelligence and function Can with hormone therapy with Chromosome Number: Abnormal Sex Chromosome Number 27 Chromosomal Inherit Klinefelter Syndrome (XXY) Male with underdeveloped testes and Male prostate; some breast overdevelopment prostate; Long arms and legs; large hands Near normal intelligence unless XXXY, XXXXY, Near etc. etc. No matter how many X chromosomes, No presence of Y renders individual ma...
View Full Document

This note was uploaded on 01/22/2012 for the course BIOLOGY SC Bio Sci 93 taught by Professor Dr.dianeo'dowdanddr.rahulwarrior during the Summer '10 term at UC Irvine.

Ask a homework question - tutors are online