monohybrid inheritance

Question 1

what does locus mean

Answer 1

the specific place on a chromosome where a gene is located

Question 2

meaning of homozygous and heterozygous

Answer 2

homozygous- possessing two identical alleles of the same gene

heterozygous- possessing two different alleles of the same

Question 3

what is pure breeding

Answer 3

an organism which when crossed with itself or others like itself, always produces offspring like itself . It is homozygous

Question 4

what is selfing

Answer 4

crossing an organism with itself or with others like itself

Question 5

what is a dominant allele

Answer 5

an allele that is always expressed in the phenotype

Question 6

what is a recessive allele

Answer 6

an allele that is only expressed when homozygous/ only affects the phenotype of an organism when the dominant allele is not present

Question 7

what is codominance

Answer 7

both alleles are expressed in the phenotype , both alleles affect the phenotype of a heterozygous organism

Question 8

what is F1 and F2

Answer 8

f1- the first filial generation- offspring of two pure breeding parents

f2- the second filial generation- offspring resulting from selfing f1

Question 9

how do you step by step set up a monogenic cross

Answer 9

1) state parents phenotype
2)state genotype
3) show gametes
4)f1 generation; punnet square
5)state f1 phenotypes
6)state f1 genotypes
7)ratio

example:
1. round seeds x wrinkled seeds
2. RR x rr
3. R R x r r
4. (punnet square for f1 gen)
5. 100% round seeds
6. 100% heterozygous Rr

Question 10

what can back crosses be used for and how

Answer 10

-to test whether a plant is dominant homozygous or heterozygous e.g Rr or RR

-can be done with known genotype e.g homozygous recessive, and crossed with unknown

Question 11

what is chi squared used for in genetics

Answer 11

-to prove there is no difference between the observed and expected ratios and genetic patterns