Answer:
A molecule is an electrically neutral group of two or more atoms held together by chemical bonds.
Answer:
cell memberane
Explanation:
cell memberane controls things going in and out of the cell
All of the following contributes to turbulent blood flow except third and fourth heart sounds.
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The blood flow in human body is always described to be laminar. Some conditions cause the high flow when there is an ascending aorta. This causes the laminar flow of blood into turbulent. When this occurs the flow of the blood will not be smooth and linear.
When the kinetic energy in the fluid flow increases the turbulent flow of blood occurs. Both the magnitude and the direction of the flow changes in this type of blood flow. These are caused by the irregularities in the vessel walls, flow rates to ne higher and opening of the valves of the heart.
Researchers selected candidate genes by identifying homozygous tracts shared by all three siblings along with the parental phenotype, this type of study is applied for the inheritance of recessive genes. Since the recessive genes can not be expressed in heterozygous genotype, the back tracking of carriers and homozygous recessive individual will help understand its inheritance pattern. The inheritance of dyt2 can be autosomal recessive. It is usually passed on to progeny of two carriers.
Answer:
Answer is option A.
Vestigial features are fully developed and functional in one group of organisms but reduced and function less in a similar group.
Explanation:
- Vestigial structures are anatomical features such as cells, tissues or organs in an organism that are previously functional and performed some important functions in the organism but no longer serve any functions in the current form of the organism and become useless as a result of a large evolutionary change. Examples include the coccyx or the tailbone in humans, the pelvic bone of a snake, wisdom teeth in humans, nipples in human males, the wings of flightless birds such as kiwi, ostrich, etc.
- Homologous features are the features that are similar in different organisms having similar embryonic origin and development and are inherited from a common ancestor that also had that feature. Also, they might have different functions. An example is the presence of four limbs in tetrapods such as crocodiles, birds, etc.
- Analogous features are the features that are superficially similar in different organisms but had separate evolutionary origins i.e., different in origin, but similar in function. An example includes the wings on a fly, a moth, and a bird where the wings were developed independently as adaptations to perform the common function of flying.
- Polygenic features are the traits or features that are controlled by multiple genes that are located on the same or different chromosomes and are also affected by the environment. These features do not follow Mendel’s pattern of inheritance and are represented as a range of continuous variation. Examples of polygenic traits or features include skin color, height, hair color, eye color, etc. For example, there is wide variation in the human skin color (from light to dark) and height (short or tall or somewhere in between).
- Sympatry describes a species or a population that inhabit the same geographic region at the same time. In sympatric speciation, new species are evolved from a surviving ancestral species while both the species inhabit the same place at the same time i.e., in a single population, reproductive isolation occurs without geographic isolation.
