Answer:
I) Sexual reproduction
II) Mutation
Explanation:
Variations refer to the difference observed within organisms of the same species. Variation are introduced into a population by:
- new genetic combinations that occur during sexual reproduction (i.e during meiosis)
- mutations, spontaneous changes that occur in genes and chromosomes.
ANSWER:
Index Fossils can be used to identify a specific period of time
Answer - B
Fish and reptiles both are ectothermic but fish have gills and reptiles have lungs. Ectothermic organisms do not have an internal mechanism of regulating their body temperature and are dependent on their atmosphere for temperature regulation. Fish, reptiles and invertebrates are examples of ectothermic organisms.
Answer: "alga" / "algae" ;
(or, in some cases, "cyanobacterium" / "cyanobacteria").
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<u>Note</u>: This applies to marine lichens—as well as lichens on land.
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Answer:
C. release of neurotransmitters
Explanation:
The action potential is an explosion of electrical activity that is created by a depolarizing current. This means that some event (a stimulus) causes the resting potential to move toward 0 mV. When the depolarization reaches about -55 mV a neuron will fire an action potential.
