Answer:
The correct answer is option d.
Explanation:
In a fish, the heart comprises two chambers, a ventricle, and an atrium. The deoxygenated blood comes through the body, moves into the atrium and then into the ventricle, from where it is pushed towards the body through the gills.
The pumping of the blood via the heart takes place via the capillary beds of the gills and via the tissues’ capillary beds. When the blood come in the capillary beds of the gills it gets slow down. It moves gradually via its path to the tissues and requires skeletal muscular activity to help the blood to mediate towards the heart again. Thus, a fish is dependent upon the physical effort for blood to get circulated again to the heart.
The heart of an amphibian-like the frog exhibits three chambers, two atria and one ventricle. In the process of circulation, that is, in the ventricle, the oxygenated and the deoxygenated blood gets mixed prior to being impelled out of the heart. However, amphibians possess lower metabolisms and thus, they need less oxygen. The requirement of a lesser amount of oxygen puts less pressure on the heart to provide blood with high oxygen. Thus, a heart comprising three chambers is suitable for the requirements of amphibians who could absorb oxygen via their moist skin.
Answer: Mutation
Explanation: Mutation is a change in DNA sequence, it may occur due to error when the DNA is copied or it can arise from various environmental factors such as exposure to chemicals, UV radiation, Highly infectious microbes.
Mutation maybe spontaneous. Acquired mutations occur at some point in a person's life and are present only in certain cells, not in every cell in the body while some may target a tissue, an organ or an entire system.
Farmers want their plants to photosynthesise as much as possible in order to increase their crop rate.
Without enough light, a plant cannot photosynthesise very quickly, even if there is plenty of water and carbon dioxide. Increasing the light intensity will boost the speed of photosynthesis.
Sometimes photosynthesis is limited by the concentration of carbon dioxide in the air. Even if there is plenty of light, a plant cannot photosynthesise if there is insufficient carbon dioxide.
If it gets too cold, the rate of photosynthesis will decrease. Plants cannot photosynthesise if it gets too hot.
Farmers can use their knowledge of these limiting factors to increase crop growth in greenhouses. They may use artificial light so that photosynthesis can continue beyond daylight hours, or in a higher-than-normal light intensity. The use of paraffin lamps inside a greenhouse increases the rate of photosynthesis because the burning paraffin produces carbon dioxide, and heat too.
<em>in the unicellular organisms organelles must have to work properly to maintain homeostasis ..
<u>in developed organisms whole systems have to work properly to maintain homeostasis but in unicellular organisms as no system is present so just organelles are responsible..</u>
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