genetics Flashcards
what are chromosomes?
structures in cells made of proteins and DNA
where do you get your chromosomes from?
your mom and dad (parents)
What is the sex-chromosome combination for females?
XX
What is the sex-chromosome combination for males?
XY
What is an inherited trait?
A trait passed down from parents to offspring
What is an acquired trait?
A trait that one learns during their lifetime
What is heredity?
The passing down of inheritable traits from one trait to the next
What is a gene?
A part of a chromosome that contains the code for a specific trait?
What are alleles?
Different versions of genes that are represented by letters
What is a dominant allele?
A dominant allele is an allele that will always be shown in the phenotype when at least one is present in the genotype.
What is a recessive allele?
A recessive allele is an allele that represents a trait that is hidden when there is a dominant allele present in the genotype.
What does homozygous mean?
purebred - 2 of the same allele in the genotype
What does heterozygous mean?
hybrid - different alleles in the genotype
What is a phenotype?
The physical description of a trait that an organism has
What is a genotype?
The letter representation of the combination of alleles
What is a Mendelian trait?
A trait that has two alleles, a dominant allele and a recessive allele
What is incomplete dominance?
heterozygous genotype and the alleles mix to make a new variation of the trait that is a mix of the two alleles
What is co-dominance?
heterozygous and both alleles are dominant so they are both represented
What is a sex-linked trait?
A sex linked trait is a trait that is carried on the sex chromosomes.
Why do sex linked traits affect males more?
males only have 1 copy of the X chromosomes, so even if the trait is recessive, they only need 1 copy of it for it to be expressed.
How are sex-linked traits written?
A superscript next to the X
What is the difference between meiosis and mitosis?
meiosis is meant for reproduction (4 daughter cells) and mitosis is meant for copying or duplicating cells (2 daughter cells)
