The technological advancement that was needed to be made before scientist began to observe cells was the invention of the microscope. I have answered this question before on here
Answer:
In roots, the vascular tissues, i.e., xylem and phloem, are found in the central vascular cylinder, while in stems these tissues are dispersed throughout the stem, generally arranged as a ring towards the outside of the stem (epidermis)
Explanation:
Vascular plants have two different transport tissues: xylem and phloem. The xylem transports water from roots to stems and leaves, while the phloem transports food (i.e. dissolved sugars) from the leaves to all parts of the plant. In roots, vascular tissues form a central core in order to withstand stretching forces. Moreover, in stems, vascular tissues are dispersed (generally concentrated towards the epidermis), in an arrangement that enables them to resist compression and bending forces.
Dopamine
On a biochemical level, cocaine blocks the reabsorption of the neurotransmitter dopamine.
Dopamine is a neurotransmitter (chemical) released by nerve cells in the body to transmit information from one neuron to another. Dopamine performs various important roles in the brain and body. Cocaine, which is a drug of abuse, blocks the reabsorption of dopamine. Cocaine acts by binding to the dopamine transporter, and stops the removal of dopamine from the synapse. Dopamine then increase in the synapse to form an amplified signal to the receiving nerve cells. This result in euphoria (feeling of intense excitement) experienced immediately after administering the drug.
Answer:
Bird "A" has a broad, sturdy beak and bird "B" has a long, slender beak.
Explanation:
this is true because sturdier beaks are better adapted to consuming hard foods, whereas birds that have to be able to reach their beaks into holes or consume nectar would need slimmer beaks.
