Answer:
your arteries that are connected to your lungs are also connected to your heart and then you need to be in the vena cava which are connected to your heart as well so you need the veins
This statement means that evolution has happened by getting the genes of the right trait expressed at the right time to help adaptability.
Explanation:
Evolution is a result of natural selection which emphasize on the survival of the fittest. But the occurrence of this trait has been possible with genetic variation. It means that if the genes for the particular feature is not present in the genome how would it occur and adapt to the environment. Thus, evolution promotes the most available option for the adaptation and hence for natural selection.
We can conclude that all features are not adaptable some are the results of genetic drift or mutations.
In case of cheetah, the faster running genes would have been there they got expressed over the period of time for better adaptability.
Answer:
<u>the bottleneck effect</u>
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Explanation:
Genetic drift has an important impact on the small populations. mutations, which are spontaneous heritable changes in the genetic code, made up of DNA. Here, mutations accumulate over time in a group, modifying the distribution of alleles or various forms of a gene. Natural selection may result in a loss of diversity in a population called genetic drift; one trait's allelic frequency rises while others become less prevalent. Typically such differences exist because of occurrences of mutation and recombination.
Some mutations or alleles may become extinct from the population.
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Variants of a gene accumulate and are transmitted across generations; the frequencies of these occurrences are altered and become more stable in genetic drift- they become genetically distinct and may eventually form a new species after isolation. This may be further compounded through other phenomena such as the founder effect where a group separates and genetic diversity decreases; and the bottleneck effect where barriers to reproduction or the die-off a population increases genetic drift.
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Answer:
Option-B
Explanation:
Schleiden was a German botanist and Schwann was a German zoologist who independently observed that plants and animals are made of cells.
Once when they together met in a conference, they shared what they observed and later both reached the conclusion that cell is the functional and structural unit of living organisms.
In the given question, since Schwann was a zoologist, therefore, he concluded that the cell in an organism must function properly whereas Schleiden was a botanist and concluded that the different structures of a plant are composed of cells.
Thus, Option-B is the correct answer.
