week 5 - genetics Flashcards
1
Q
what are genes?
A
- segment of DNA within the chromosome
- basic unit of genetic info for a specific character
- gene is code for proteins
2
Q
gene is the basic unit of what?
A
inheritance
3
Q
what is the alternative version of a type of gene?
A
- allele
4
Q
homozygous
A
- an individual who carries two copies of the same allele
5
Q
heterozygote
A
-individual that carries different alleles
6
Q
gene mutation
A
- different alleles originate from mutations
- definition - change in DNA that makes up a gene
7
Q
mutations can be:
A
- harmful
- beneficial
- neutral
8
Q
genotype
A
- genetic makeup of an organism
9
Q
phenotype
A
- observable physical characteristics
10
Q
dominant and recessive alleles
A
- dominant: (capital) determines phenotypes
- recessive (lowercase) is repressed by the dominant
11
Q
blending inheritance theory
A
offspring should have a phenotype intermediate between those of their parents, but many observations do not fit this theory (i.e. eye colour skipping generations)
12
Q
mendel and true-breeding
A
- when parents are self-pollinated, the offspring are identical to parents
13
Q
Mendel’s theory (6)
A
- proposed the “particulate” theory of inheritance
- alleles cause variation in characters
- offspring inherit one copy of a gene/allele from each parent
- alleles separate into different gametes
- gametes fuse without regard to which allele they carry
- alleles can be dominant or recessive
14
Q
Mendel’s first law: equal segregation
A
- states that the two copies of each gene/alleles separate during meiosis (they end up in different gametes)
- Punnett squares can be used to consider all possible combinations of gametes/outcome of genetic crosses
15
Q
mendel’s second law: independent assortment
A
- to form gametes, alleles for one trait combine randomly with alleles for other traits (i.e. texture and colour)
