Answer: a. an anticodon and an amino acid
Explanation:
The following is a typical structure The tRNA where we can observe an anticodon that binds to the nucleotide sequence of the mRNA and an amino acid that in triplet encodes for an protein.
The nutrients get to the cells in a flatworms solid acoelomate body by diffusion process. Flatworms feed primarily on protozoa and bacteria, smaller worms and tiny organisms, dead or alive, that they come across. Based on the species of the flatworms , they also consume plant materials. They rely on diffusion to transport oxygen and nutrients to their internal tissues.
Answer:b
Explanation:some seeds do not germinate during adverse conditions.this is called dormancy.this may occur due to hard seed coat.this seed coat prevents the entry of water and oxygen which are necessary for the plant to grow and germinate.
Water is a nessesary medium for essential metabolic reactions in the seed.the temperature at which is seed would germinate also varies.
Oxygen is needed for a germinating plant to obtain energy through respiration. The seed coat may also be so tough that they resist growth and expansion from taking place.
Seeds are able to break dormancy on their own.some may need to undergo natural processes that lead to softening.this process may be slow.some others may need heat or certain nutrients.
Germination of seed occurs when the dormant plant has taken in water and oxygen to show high metabolic activities leading to the formation of a seedling.