Bio 1100 Mistakes in Meiosis Vocab

What are autosomes?

carry genes that determine physical and physiological traits, these are identical in males and females

What are sex chromosomes?

determine an individual’s sex, males have XY and females have XX

What is a nondisjunction

when gametes have the incorrect number of chromosomes, too many or too little

What happens when a nondisjunction happens in anaphase I?

called a first division nondisjunction, will result in two of the four daughter cells having less than normal chromosomes and the other 2 having too many chromosomes

What happens when a nondisjunction happens in anaphase II?

called a second division nondisjunction, will result in one of the four daughter cells having less than normal chromosomes and the other 1 having too many chromosomes, while two have the normal amount

What does n+1 mean?

cell has an extra chromosome

What does n-1 mean?

cell is missing a chromosome

What is trisomy?

3 copies of the same chromosome

What is monosomy

only 1 copy of the same chromosome

What do people with trisomy have?

the over expression of that chromosome, is lethal, the larger the chromosome the more lethal it is, dosage effect

What extra copy of chromosome can be tolerated?

Sex chromosomes, because of X chromosome inactivation

What is X chromosome inactivation?

process where one of the two X chromosomes in females is silenced or turned off early in embryonic development, is random and permanent

Down syndrome

trisomy of chromosome 21, the second smallest chromosome, less lethal