Answer:
Control group: volunteer stationary bike riders in a pollution-free chamber
Experimental group: volunteer stationary bike riders in a chamber filled with air pollutants common to Los Angeles
Independent variable: exposure to air pollution
Dependent variable: The heart rates (physical fitness) of the volunteer riders.
Explanation:
In a scientific experiment, data is compared between the control group and experimental group to ascertain the effect of the independent variable on the dependent variable. A control group is the group in an experiment that is not treated with the independent variable i.e. the independent variable is controlled while the experimental group is the group that is treated with an independent variable.
N.B: The independent variable is the variable controlled by the experimenter in order to influence the dependent variable (measurable outcome).
In this experiment, the independent variable is the AIR POLLUTION the volunteer riders are exposed to while the dependent variable is the PHYSICAL FITNESS/ HEART RATES of the volunteer riders, which is dependent on the exposure to air pollution (independent variable).
The control group in this experiment is the volunteer riders placed in a POLLUTION-FREE CHAMBER where the independent variable cannot influence or have any effect on the measurable variable (dependent). The experimental group is the volunteer riders placed in a CHAMBER FILLED WITH AIR POLLUTANTS. The independent variable (air pollution) has been changed in the experimental group.
Ans.
Hormones are regulatory substances synthesized by various plants and animals and play role in proper growth, development, and maintain homeostasis. Hormones are released by signalling cells and show their actions after binding to specific receptors present on the surface or inside of the target cell.
Hormones, for which receptors are present inside the cells (in cytosol or nucleus) should be hydrophobic in nature. This is because plasma membrane is made up lipid molecules and small, hydrophobic, uncharged molecules can easily pass through this. For example, cortisol, estrogen, and progesterone hormones are lipid-derivatives and receptors for these hormones are present inside the cells.
Diabetes insipidus is a disease characterized by excessive thirst and the excretion of large amounts of highly diluted urine, which can not be reduced by a reduction in fluid intake.
Diabetes insipidus is due to a deficiency of antidiuretic hormone or insensitivity of the kidneys to this hormone. This hormone causes water reabsorption via action on the distal segment of the nephron during dehydration.
Emperor penguins have the ability to 'recycle' their own body heat. The arteries and veins lie close together so that blood is pre-cooled on the way to a penguin's feet, wings and bill and warmed on the way back to the heart. Emperors' feet are adapted to the icy conditions
Natural selection is the process that result in the adaptation of an organism to environment by means of selectively reproducing changes in its genotype, or genetic constitution. It is the a key mechanism of evolution. Charles Darwin popularised the term "natural selection" contrasting it with artificial selection, which is intentional, whereas natural selection is not.
To make it simple, let's have a group of beetle composing of green and some are brown as an example. here, there is a variation in traits. Since the environment could not support continuous population growth, not all species can reproduce to their full potential. Green beetles can easily be eaten by other species like birds compared to brown beetles. The surviving brown beetles will then generate brown offsprings because their trait has a genetic basis. Since more brown beetles survive and becomes more common in the population, the process continues until all individuals will eventually be brown. so basically, if you have variation, differential reproduction, and heredity, you will have evolution by natural selection as an outcome.
