I need help with some science questions ^^?

Question

1)A) what is the difference between complete and incomplete dominance?

B)what is codominance?

2) Imagine that you have two pure lines for each of three species of plants. For each species, one pure line produces only blue flowers and the other pure line produces only red flowers. You do a series of crossing experiments of each species. For species #1, you find that the flowers of the F1 offspring are all blue. The flowers of the F1 offspring of species #2 have a mottled red and blue appearance. For species #3, the F1 offspring all have purple flowers.

A) in which of these species are the two alleles for flower colour codominant?

B)in which species is one flower colour allele completely dominany over the other?

C)which species displays incomplete dominance for the flower colour alleles ?

3)A) Can an individual ever possess more than two alleles for a particular gene? explain.

B) Can there be more than two alleles for a particular gene present in a population? explain.

Answer 1

1)) complete: you either have brown eyes or blue eyes. you don't have "blue-brown" eyes(incomplete), nor do you have eyes that have blue spots and brown spots(codominance). it's either one or the other.

incomplete. a black and white couple have a kid. the kid has beige skin, a mix of the skin colour of the parents. if it was complete dominance, the kid would be either black or white, like mom or dad. if it was codominance, the kid would be like a zebra, with both black and white patches of skin

codominance. people with AB type blood are codominant. both traits are exhibited equally.

2) codominant means both traits are shown, ie #2

completely dom means only one is shown, ie #1

incomplete means you get a mix of both, ie #3

3) a) yes, but only with people who get more than 2 copies of the same chromosome. people with Down's syndrome have 3 copies of chromosome 22 (not sure about the number), so they can potentially have 3 different alleles on a certain gene that's on chromosome 22. when an individual gets more than 2 copies of a chromosome, it's called polyploidy. in humans, this is very rare, and most of the time, it's regarded as a genetic defect (ie down's syndrome. but in plants, polyploidy is quite common, and having more than 2 copies of a chromosome can certainly mean they get more than 2 alleles of a gene.

b) yes. blood type has 3 allelles. A, B and i. and by mixing them, you get people with A type blood, B type blood, AB type blood and O type blood