Answer:
Air-sea exchange is a physio-chemical process and is important for the cycling of gases such as carbon dioxide, methane, nitrous oxide, dimethylsulfide and ammonia
CONTRACTILE RINGS are a contractile ring of actin micro filaments that eventually results in the division of the cytoplasm.
The contractile ring are usually formed during the early anaphase phase of the cell division cycle. During the cellular cleavage, the contractile rings tighten around the cytoplasm of the cell until it is pinched into two daughter cells.
Answer:
A. Phototropism and geotropism are adaptations of plants that allow for survival.
Explanation:
Ideally, TROPISM is the growth response of plants to their environment due to external stimuli as rightly stated in this question. However, based on what stimulus the plant is responding to, there are different types of stimulus.
Phototropism (photo-light) is the response of an organism to a light source while Geotropism (geo- gravity) is the response of an organism to gravity. Hence, based on this question, a plant's response to moonlight is phototropism while it's response to gravity is geotropism.
Also, tropism can either be positive or negative depending on whether the response is towards the stimulus (positive) or away from the stimulus (negative). Therefore, the FALSE statement is "Phototropism and geotropism are adaptations of plants that allow for survival"
Answer:
B) astrocytes
Explanation:
Cells other than neurons that play an important role in the normal functioning of nervous system are called Neuroglia or glial cells.
Satellite cells, astrocytes, schwann cells and oligodendrocytes are all examples of glial cells.
⇒Satellite cells provide protection and nutrition to cells in peripheral nervous system ( peripheral nerves and ganglia).
⇒<em><u>Astrocytes</u></em> play an important role in central nervous system (brain and spinal cord). They provide protection to neurons, scavenge ions, form the blood-brain barrier and also maintain extracellular environment suitable for neuronal functioning.
⇒Schwann cells are found in the peripheral nervous system and myelinate the axons of neurons.
⇒Oligodendrocytes are found in central nervous system and produce myelin sheath which myelinates (insulates) axons of neurons. Their function is similar to schwann cells but in the central nervous system.
From the above discussion it is clear that the answer is B) Astrocytes as these maintain a suitable chemical environment for the neurons.
