What does it mean when we say a muscle contracts involuntarily?

What is the difference between self-pollination and cross-pollination? question 2 options: self-pollination leads to the creation of a fruit. cross-pollination does not. during cross-pollination, ovules are carried from one plant to another plant.. during self-pollination the ovules stay on the same plant. during cross-pollination, ovules are carried from one plant to another plant.. during self-pollination the ovules stay on the same plant. during cross-pollination the pollen grains are carried from one plant to another plant. during self-pollination the pollen and ovules are from the same plant. during cross-pollination, the pollen grains travel from the stigma to the anthers. during self-pollination, the pollen grains travel from the anthers to the stigma.

Which of the following structures is not found in both plant and animal cells? a) chloroplast b) cytoskeleton c) ribosomes d) mitochondria

What is thought to have caused the mass extinction at the end of the cretaceous period?