Choices 1, 2, and 3 all emit carbon dioxide, not enough to destroy the planet, but they still can cause it over a large amount of time, due to Carbon Dioxide being a greenhouse gas. Therefore, the answer is 4. Bicycles do NOT emit any carbon dioxide at all.
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.
These animals were preyed upon by equally large carnivores such as saber toothed cats, cave bears and dire wolves.
Btw it's (QUATERNARY) *
The algae in the ocean have a very high Net Primary Productivity (NPP) and a very low amount of store biomass. This is because THE GROWTH RATE OF ALGAE IN THE OCEAN IS HIGH. The store biomass is low because THE PRIMARY CONSUMERS FEED ON THESE ALGAE THUS LOWERING THE BIOMASS AMOUNT. The production of biomass is related to the NPP.
Cells will usually divide if they receive the proper signal at a checkpoint in the G1 phase of the cell cycle. In mammalian cells , this checkpoint is called the restriction point. The G1 phase is a phase of the cell cycle that takes place in eukaryotic cell division. In this phase the cell synthesizes mRNA and proteins in preparation for the subsequent steps leading to mitosis. It ends when the cell moves into the S phase of interphase.