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How many chromosomes are humans supposed to have?
46
44 of the chromosomes are called.... And what are they?
autosomes, body chromosomes
2 of the chromosomes are...
sex chromosomes
What is a karyotype?
A picture of chromosomes
When scientists study chromosomes, why do they take the picture during mitosis?
That is when the chromosomes are coiled and easier to see.
Chromosomes are arranged into _______ sets
23
Autosomes are paired with their ___________ match and are arranged _______ to __________
homologous, largest, smallest
_____ chromosomes are paired last
sex
Who is responsible for the gender of the baby?
male
When homologous chromosomes fail to separate, __________ occurs
nondisjunction
If nondisjunction occurs, it results in an ___________ number of chromosomes
abnormal
What syndrome does one have when they are missing a chromosome? How many chromosomes would they have?
Turner Syndrome, 45
What syndrome does one have when they have an extra chromosome?
Down Syndrome
If someone has ___________ syndrome they have 3 copies of chromosome number _______
Klinefelter's, 21
If someone has one chromosome (XO) what is that called?
Monosomy
When someone's chromosomes look like this: XXY, this is called
Trisomy
People with Klinefelter's Syndrome are often _________
sterile
Why do people study human traits?
To figure out how the trait is passed from one generation to the next
Heterozygous figures are called ________
carriers
What are some dominate disorders?
Achondroplasia and Huntington's
What is another name for dwarfism?
Achondroplasia
What is an example of Nature vs Nurture
Identical twins having the same DNA but end up with different personality due to different living environments
PKU (phenylketonuria) is caused by....
a recessive allele found on Chromosome 12
What does PKU cause?
accumulation of phenylalanine in brain tissue causing mental retardation
If PKU is identified early on, babies need to be put on a bigger _____ ______
dietary intake
What is Tay-Sachs?
A degenerative nervous tissue disease leading to death in the first year of life
PKU and Tay-Sachs are part of the...
newborn screening system
Babies will die if they are _________ ___________ to achondroplasia
homozygous dominant
Achondroplasia is caused by a ___________
mutation
The ___________ disease is a nervous tissue disease and causes.....
Huntington, loss of muscle control eventually leading to death in their late 30s
_________ ________ disease is caused by a single nucleotide change in the DNA
Sickle Cell
Sickle Cell causes....
Causes red blood cells to form a crescent shape when oxygen levels are low
When heterozygous of sickle cell it is protection towards __________
malaria
Cystic fibrosis is commonly caused by... that causes.....
a missing codon in the gene causing the protein to be affected
Cystic fibrosis affects individuals by making them
have trouble moving chloride through the cell membranes causing thick mucus and digestive problems
Females having one X randomly inactivated is called a _______ ________
Barr Body
Colorblindness is 1 in 10 ______
males
Colorblindness is 1 in 100 ______
females
Hemophilia is a _______ ________ disorder
blood clotting
What is polygenic inheritance?
many genes that affect a certain trait
What is the law of segregation
when two alleles for a heritable trait are separated during gametogenesis and end up in DIFFERENT gametes
What is the law of independent assortment?
when each pair of alleles segregates INDEPENDENTLY of other pairs of alleles during gamete formation
What are gametes?
sex cells
What is a structure of 4 sister chromatids called?
tetrad
The joining of the male and female reproductive cells is called... (gametes are joined here)
fertilization
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