Which component of nerve cells contains the nucleus?
axon
cell body
neuron
dendrite
The component of nerve cells that contains the nucleus is the cell body.
A girl has her eyes shut and is standing inside a brightly lit room. What happens to her pupils when she opens her eyes? Why?
Her pupils grow because the muscles contract.
Her pupils grow because the muscles relax.
Her pupils shrink because the muscles contract.
Her pupils shrink because the muscles relax.
Her pupils shrink because the muscles contract. When the girl opens her eyes and is exposed to the brightly lit room, the muscles in her iris contract, causing the size of her pupils to decrease. This constriction of the pupils allows less light to enter the eyes, helping to protect the sensitive photoreceptor cells in the retina from excessive light stimulation.
the human body has four types of tissues. What part of the eye uses muscle tissue for opening and closing movements?
Cornea
Iris
Sclera
Retina
The part of the eye that uses muscle tissue for opening and closing movements is the iris. The iris contains smooth muscle fibers that control the size of the pupil, allowing it to constrict or dilate in response to changes in light intensity.
How do polar bears maintain homeostasis in freezing cold weather?
Their metabolism slows down to preserve heat.
They hibernate in warm areas in order to heat their bodies.
Their thick fur retains heat.
Their metabolism speeds up to produce heat.
Polar bears maintain homeostasis in freezing cold weather by their metabolism speeding up to produce heat. Polar bears have a lot of insulating fat and a thick layer of fur, which helps them retain heat. In addition, their bodies have adaptations that allow them to generate heat through increased metabolism. This increased metabolism is achieved by breaking down stored fat and increasing the production of heat through cellular respiration. By speeding up their metabolism, polar bears regulate their body temperature and stay warm in cold environments.
Which example shows an organism that cannot reach homeostasis through internal changes
A dog shivers when it is too cold.
Circulation decreases in a bird when it becomes too warm.
A person gets a fever in response to a flu infection.
A lizard is cold, and it moves to a sunny rock to warm up.
The example that shows an organism that cannot reach homeostasis through internal changes is "A lizard is cold, and it moves to a sunny rock to warm up." In this scenario, the lizard is relying on external environmental changes (moving to a sunny rock) to achieve homeostasis, rather than undergoing internal physiological changes.
How is homeostasis achieved?
Cells maintain internal stability.
Cells secrete stomach enzymes.
Cells control involuntary movements.
Cells control voluntary movements.