Genetics Flashcards
What is a chromosome?
condesed DNA thats wrapped around histones
What is an allele? 2 facts?
an allele is all possible types of a gene
(ex. brown, blue, or green eyes)
1) a person can only have 2 alleles in one gene
2) everyone has the same pairs of genes but different alleles
What are gonads and gametes?
gonads- organs that produce sex cells
gametes- sex cells
What does homozygous and heterozygous mean?
Homozygous- same alleles (ex. BB)
Heterozygous- different alleles (ex. Bb)
What are phenotypes and genotypes?
Phenotype- what trait is expressed (ex. brown
Genotype- what are the genes (ex. heterozygous, big B little b)
what is Chargaff’s rule?
of purines = # of pyrimidines
What is chromatin?
dispersed DNA
“normal life”
What are the names of purines and pyrimidines, what do each go with.
Purines- adenine (goes with thymine 2 bonds) and guanine (goes with cytosine 3 bonds)
Pyrimidines- Thymine (goes with adenine 2 bonds) and cytosine (goes with guanine 3 bonds)
How many rings do purines and pyrimidines?
purines- 2
pyrimidines- 1
what is meiosis and mitosis?
meiosis- 2n splits to n/duplication of sex cells
mitosis- 2n multiplies/duplication of skin cells
what is a chromosomal disorder?
a complete addition or deletion of entire radicals. (ex. supermale xyy)
What is down’s syndromes/trisomy 21’s chromosome pair?
3x chromosome #21
