What are the most difficult concepts for students to understand?

What determines the function of a protein apex?

Which one of the following blood vessels carries oxygenated blood

What is true of an atom's nucleus? It is positively charged and takes up most of the atom's space. It is negatively charged and takes up most of the atom's space. It is positively charged and includes most of the atom's mass.

Which of the following cells would not divide using mitosis? gamete mammal cell flowering plant cell fungal cell bacterial cell

Some regions of chromosomes are more likely to cross over compared to others. Such a region is called a "hot spot". Gene A and gene B, which are in a hot spot for crossing over, are 5,000,000 bp apart on the same chromosome.

Which of the following substances is used up during photosynthesis? Oxygen Sugar Sulfur dioxide Water

What is the role of mouth

Which atoms are found in all carbohydrates?

Which group of animals has existed the longest? a. tubulidentates b. perissodactyls c. artiodactyls d. sirenians

In which organelle does the chemical process of photosynthesis occur? mitochondria nucleus chloroplast endoplasmic reticulum