If producers were removed from an ecosystem, it would fall apart. Producers are the organisms at the bottom of the food chain, which produce glucose and nutrients for consumers. If producers were removed from an ecosystem, the consumers would have no nutrients and die, causing their predators to die, and so on.
Answer:
C
Explanation:
Usually if 1 out of 4 children in a family have a different hair color, it is because of the recessive gene passed down from the mother or fathers genes.
When neurons are not producing electrical signals we say that they are at resting phase: voltage across their membrane is called the resting membrane potential, or the resting potential.
This potential is determined by the concentration of ions (Na, K) across the membrane and by membrane permeability to each type of ion. While the ions move through channels down their gradients they lead to a separation of charge and that is what creates the resting potential.
The membrane of the neuron is much more permeable for K ions so the resting potential is close to the equilibrium potential of K+.
Answer:
black carbon which is "B"
Calcium levels in the body are maintained by hormones. If the blood calcium level rises above a set point, calcitonin is secreted by the thyroid gland and sets into motion responses to lower the blood calcium back to the set point. If the blood calcium level falls below a set point, the parathyroid gland secretes parathyroid hormone that sets into motion responses to raise the blood calcium. These homeostatic responses are examples of:
a. positive feedback
b. effectors
c. sensors
d. negative feedback
Answer:
d. negative feedback
Explanation:
Negative feedback responses are the ones that counteract the change. Any alterations in the internal body conditions such as blood calcium levels are sensed by receptors. The information is sent to the brain which in turn commands the effectors such as endocrine glands to secrete the required hormones to restore the normal conditions. Here, changes in the calcium levels are counteracted by the secretion of calcitonin and parathyroid hormones and the calcium is maintained within a narrow range. This represents negative feedback.
