Genetic drift happens by chance and can make an allele disappear completely from a gene pool, even if it was a desirable trait that should have been passed down to offspring. The random sampling style of genetic drift shrinks the gene pool and therefore alters the frequency the alleles are found in the population.
3) decrease
Without the green house effect, earth would be like a solid ball of ice and rock.
Life as we know it wouldn't exist without greenhouse gases.
The temperature would drop below 0° Fahrenheit!
Answer:
The flow of energy in ecosystems is unidirectional or one-way.
Explanation:
Energy is the ability to do work. Energy flows in one direction in an ecosystem and is not recycled. This is because during the transfer of energy from one level to another, energy is lost. Most of the energy received from the sun by producers, plants, is lost as heat to the surroundings. The rest energy is converted by plants to produce food in the form of chemical energy.
Primary consumers feed on plants and secondary consumers feed on the primary consumers and so on up to quaternary consumers. However, at each level of energy transfer, some energy is lost as heat during respiration, some as unused or undigested materials, while some others are used for each organisms metabolic activities. About 90% of energy in a trophic is used at that trophic level. Therefore, only about 10% as much energy is available to organisms at each successive trophic level. Therefore, energy is not recycled in ecosystems.
Earth's atmosphere maintains its temperature by means of the earth's energy balance. This refers to how incoming from the sun and outgoing energy from the earth are in balance, thereby keeping earth's temperature constant.
Decomposers, are organisms such as bacteria, fungi, and small animals such as ants and worms that eat and decompose dead and waste organic matter and which recycle nutrients back into food chains making them available for plants use. Therefore, decomposers are an essential components of all ecosystems.
Answer:
b. epinephrine on beta 2 receptors causes bronchodilation
Explanation:
This is because epinephrine is an hormone and neurotransmitter that stimulate beta 2 receptors which causes signaling and their in presence in airway smooth muscle causes bronchodilation, which counter the activation of the M3 muscarinic receptors in cardiovascular. When stimulate in skeletal muscles it can lead to increased contractility and also to muscle tremors.
Since the sperm cells are haploid, the body cells are diploid. If the haploid cell is 4, double it would be 8.