<span>Additional facts:
A test cross between an organism whose genotype for a certain trait is unknown and an organism that is homozygous recessive for that trait so the unknown genotype can be determined from that of the offspring.
Answer:
You'd use it when you wish to see if the one that you think is a homozygous dominant is a purebred, because if you did get a recessive offspring then it proves that the animal is a heterozygous and not a purebred.</span>
1. The cell wall has lignin (hard substance): to prevent the xylem vessel from collapsing and withstand high pressure.
2. The absence of protoplasm (nucleus + cytoplasm) and cross wall: to allow water to move through the lumen easily.
Hope it helped!
Answer:
Glacial striation is your answer
I don't none of them are
I hope this helps!
