Explanation:
Mutations increase variation within a population.
During the process of cell division, spontaneous changes within the genome can arise. These mutations are errors occur when copies of the DNA within the cell are made; mutations may range from small changes called single nucleotide polymorphisms, to large scale deletions, and additions which span multiple genes. There are two types:
- somatic: these only occur within certain cells, and arise from environmental factors such as UV light
- hereditary: occur within germ cells of the parent and later the fertilized egg which forms a zygote; these are present within all cells of the new organism.
Further Explanation:
During reproduction other events, such as crossing over during mitosis and meiosis, mutations lead to increases in genetic variation. This variation refers to the genetic characteristics present within a species. Mutations may be either beneficial or deleterious; they are maintained within cells, as they form new traits called alleles. Beneficial mutations may confer traits that increase the fitness of a species, along with ensuring survival by conferring a protective advantage- these phenotypic differences between organisms are called adaptations.
Sequences of DNA make up genes which can have different forms called alleles. DNA, which makes up the genotype, is transcribed into mRNA and later translated into amino acids which are linked together by rRNA to form proteins which make up the phenotype of an organism.Mutations in DNA sequences affect the corresponding mRNA and thus the protein encoded.
Learn more about mutations at brainly.com/question/4602376
Learn more about DNA and RNA at brainly.com/question/2416343?source=aid8411316
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Answer:
Option A, most closely related to mammals
Explanation:
Insects like arthropods and molluscs have an open circulatory system and thus do have a distinguishable heart. Fish has two chambered heart. Reptiles have three chambered heart. Amphibians too have a three chambered heart.
All mammals and fish have four chambered heart. The right and left sides of the chambers have restricted entry and hence remain intact from each other
Hence, option A is correct
There is only one measure of "evolutionary success": having more offspring. A "useful" trait gets conserved and propagated by the simple virtue of there being more next-generation individuals carrying it and particular genetic feature "encoding" it. That's all there is to it.
One can view this as genes "wishing" to create phenotypic features that would propagate them (as in "Selfish Gene"), or as competition between individuals, or groups, or populations. But those are all metaphors making it easier to understand the same underlying phenomenon: random change and environmental pressure which makes the carrier more or less successful at reproduction.
You will sometimes hear the term "evolutionary successful species" applied to one that spread out of its original niche, or "evolutionary successful adaptation" for one that spread quickly through population (like us or our lactase persistence mutation), but, again, that's the same thing.
Answer: alpha
Explanation: Alpha particles are fast moving streams of positively charged particles that are shown to be Helium nuclei. They have a mass
number of 4 and an atomic number of 2 and a charge of +2. Alpha particles are represented as 4He2. When 238U92 becomes 234Th90, it emitted a helium nucleus 4He2. The equation for the decay is 238U92 ---> 234Th90 + 4He2.
