Suppose that in humans the ability to roll the tongue (R) is dominant to being unable to roll it (r). Having freckles (F) is dominant to having no freckles (f). A freckled tongue-roller could have which genotypes? (select all that apply)
A. RrFf
B. rrff
C. rrFF
D. rrFf
E. Rrff

A. RrFf

Explanation:

Given,

Ability to roll the tongue (R) is dominant over inability to roll it (r)

Freckles (F) is dominant to no freckles (f)

A freckled tongue-roller has dominant version of both the traits. So the traits will be visible even in the presence of only one dominant allele.

Thus, possible genotypes for a freckled tongue-roller will be :

RRFF

RRFf

RrFF

RrFf

Out of the give options only option A is the answer.

relationships aren't everything. people everyday spend there entire life depending on reltionships and for someone to be there for them when this is absurd. why must people depend on someone else to bring them happiness? i'm not saying it wrong to feel happy with someone, but people feel that they need to be in a relationship in order to feel happy, when, this is not true. you can paint, write, read ir slend tume with family ir even spend time working in yourself. this can be an exciting experience to find yourself. it's bot wrong to be in a relationship but if you let it be your only source of happiness, than you will never find true happiness.

so, relationships are not always worth it. if you are so dependent on them, than in the end they arent worth it because you will realize how unhappy you really were. some people even tend to cut ties with family because they think they cabt make them happy, obly realtionships with a lover can. false. in order to find true happiness, one must learn to love themselves if they want to love someone else. it's unhealthy to be always depend on relationships and to alqays be in and out of one.

so live life, get that job you always wanted, buy those new shoes and love yourself. depend on yourself, not others. they arent worth it, you can make yourself more happier than most people can do to you. it's not woth it. take your time and have fun.

cells use diffusion to get substances in and out of themselves. that diffusion will occur across the cell membrane or the outer covering of the cell. because we are talking about the surface of the cell, surface area and volume are  important factors here. as a cell increases in size, its surface area and volume increase as well.  we call that the surface area to volume ratio (sa: vol).  but the catch is that  volume increases at a greater rate than surface  area. in other words, as a cell gets bigger, the sa: vol gets smaller. so a really small cell like bacteria is mostly cell membrane (surface) with very little contents (volume). a really big cell like an egg, is mostly insides with a super thin membrane. so what ends up happening is that the cell cannot efficiently diffuse all of the stuff it needs in/out to survive. therefore cell size is limited to about 100mm. so how do we make organisms bigger than 100mm? cells divide! by dividing and becoming multicellular, organisms are able to grow!   check out the diagrams i attached to see the effect of sa: vol. i hope this ! good luck!