A child has type O blood. Which of the following couples could be the child's parents?

Couple 1: Mother's Type -A, Father's Type -B
Couple 2: Mother's Type -O, Father's Type -A
Couple 3: Mother's Type -AB, Father's Type -O
Couple 4: Mother's Type -B, Father's Type -AB

A.
couple 1, 2, 3, or 4

B.
couple 3 or 4 only

C.
couple 1 or 2 only

D.
couple 2, 3, or 4 only

The endoplasmic reticulum (er) is an organelle in some cells. in these cells, it is continuous with the nuclear membrane and forms a large part of the cell\'s total membrane. sort the phrases below as describing rough er, smooth er, both, or neither. note: if you answer any part of this question incorrectly, a single red x will appear indicating that one or more of the phrases are sorted incorrectly.1) found in prokaryites and uekaryotys2) involved in protein synthesis3) involve in lipid synthesis4) contains molecular chaperones in lumen5) bound with ribosomes6) involved in toxin or drug metabolism7) large systemot internnected tubules,vesicles, and sacs8) "packages" enzymes in vesicles for secretion.

The distant ancestors of tigers may have had bodies without stripes. use the theory of natural selection to explain how tigers may have evolved to have stripes.

Describe your dna model. which part do the straws represent? the pushpins? the paper clips and the black dots you made with the marker?