Answer:
Bíceps- tríceps
Explanation:
Los músculos trabajan para generar movimiento mediante la contracción de células musculares. El bíceps y el tríceps son músculos antagonistas presentes en el brazo. Cuando el brazo se acorta, el bíceps funciona como agonista (es decir, se contrae) y hace que los tendones que tiran de los huesos del antebrazo puedan doblarlo. Durante este movimento, el triceps funciona como antagonista, encontrándose en estado de relajamiento. Por otra parte, durante el estiramiento del brazo, las funciones de estos músculos se invierten, con lo cual el tríceps (agonista) se contrae y el bíceps (antagonista) se relaja.
Antibiotics should be the answer
Answer:
Both gray wolves and killer whales have live births. And Both gray wolves and killer whales are carnivores
Explanation:
Answer;
Cell membrane
A cell membrane acts as a boundary that separates things that are inside the system from those that are outside the system.
Explanation;
It is a thin semipermeable structure that surrounds the cytoplasm of a cell.
The membrane functions to protect the integrity of the internal environment of the cell by allowing selective movements of materials in and out of the cell.
The membrane consists of a phospholipid bilayer with proteins embedded in it.
Answer:
The correct answer is b. must be present in a population before natural selection can act upon the population
Explanation:
Genetic variation can be caused by mutation, recombination between chromosomes during meiosis and by fusion of two genetically different gametes during sexual reproduction.
This genetic variation is necessary for the evolution of any population. Natural selection acts on every individual and it decreases the frequency of those alleles that are not suited for the environment and increase the frequency of those alleles which helps the individual to survive in the changing environment.
Therefore genetic variation must be present in the population before natural selection act on the.
