Ques: Q: What begins when a neuron receives a chemical stimulus? Read this paragraph and choose the correct option from the provided answers: A nerve impulse begins when a neuron receives a chemical stimulus. The impulse travels down the axon membrane as an electrical action potential to the axon terminal. The axon terminal releases neurotransmitters that carry the nerve impulse to the next cell. Choices: - a induce impulse - a metabolism impulse - nerve reaction - a nerve impulse A:
Ans: a nerve impulse

Ques: Q: The shape of a virus is determined by the type and arrangement of proteins in its what? Read this paragraph and choose the correct option from the provided answers: 22.1 Introduction Viruses are the smallest biological particle (the tiniest are only 20 nm in diameter). However, they are not biological organisms so they are not classified in any kingdom of living things. They do not have any organelles and cannot respire or perform metabolic functions. Viruses are merely strands of DNA or RNA surrounded by a protective protein coat called a capsid. Viruses only come to life when they have invaded a cell. Outside of a host cell, viruses are completely inert. Since first being identified in 1935, viruses have been classified into more than 160 major groups. Viruses are classified based on their shape, replication properties, and the diseases that they cause. Furthermore, the shape of a virus is determined by the type and arrangement of proteins in its capsid. Viruses pathogenic to humans are currently classified into 21 groups. Viruses can also attack bacteria and infect bacterial cells. Such viruses are called bacteriophages. Choices: - enamel - anode - nuclei - capsid A:
Ans: capsid

Ques: Q: What 3 types of friction occur between solid surfaces? Read this paragraph and choose the correct option from the provided answers: Friction is the force that opposes motion between any surfaces that are in contact. There are four types of friction: static, sliding, rolling, and fluid friction. Static, sliding, and rolling friction occur between solid surfaces. Fluid friction occurs in liquids and gases. All four types of friction are described below. You can see a video demonstration of the different types at this URL:. Choices: - static , arching , rolling - static,desending,sliding - static , ascending , rolling - static, sliding, rolling A:
Ans: static, sliding, rolling

Ques: Q: Most, if not all, of the extant animal phyla today evolved during the cambrian period, yet many of what devastating events have taken place since then? Read this paragraph and choose the correct option from the provided answers: Describe at least two major changes to the animal phylogenetic tree that have come about due to molecular or genetic findings. How is it that morphological data alone might lead scientists to group animals into erroneous evolutionary relationships? 26. Briefly describe at least two theories that attempt to explain the cause of the Cambrian explosion. How is it that most, if not all, of the extant animal phyla today evolved during the Cambrian period if so many massive extinction events have taken place since then?. Choices: - life extinctions - earthquakes - starvations - mass extinctions A:
Ans:
mass extinctions