Genetics Flashcards
What is genetics?
The study of heredity
In addition to genes, what other factor shapes the traits an organism has?
Environment
Define gene
A unit of heredity- a segment of DNA that contains the instructions to make a protein
DNA is the “instruction manual” for making ___________, which is what results in the observed trait.
Proteins
How many copies of each gene do humans have? Where do they get these copies?
1) 2
2) one from each parent
How are genes and chromosomes related?
Chromosomes contain many genes
How many pairs of chromosomes are in somatic human cells?
23 pairs
Where does each chromosome pair come from?
One from each parent
Are genotypes always the only thing that determines an organism’s phenotype? Why or why not?
No- the environment also affects many traits
Who is considered the “father of genetics”? Why was he given this name?
Gregor Mendel- he discovered the basic principles of inheritance
What organism did the “father of genetics” study to discover the basic principles of heredity?
Pea plants
What is an allele?
One of two or more versions of a gene
For each gene, how many alleles do humans have?
2 for each gene
What is the difference between genotype and phenotype?
G- genetic makeup
P- physical appearance
In simple inheritance, how many dominant alleles are required to cause the dominant phenotype?
1
What genotype must an organism have to get the recessive version of a trait?
Homozygous recessive
What is the difference between homozygous and heterozygous?
Homozygous = 2 of the same
Heterozygous = different
