Stem cells begin to transfor into different types of cells in the human body in a process known as cell differentiation.
Cellular differentiation occurs throughout the cell development of a multi-cellular organism. It occurs when the cell changes from a simply zygote into a complex system of tissues and cell types.
Stems cells are cells which have the potential to develop into many different cell types in the body during early life and growth. Stem cells serve as internal repair system in many tissues. When stem cells divide while undergoing cell differentiation, it can either retain being a stem cell or become another type of cell like muscle cell, brain cell, or red blood cell.
Answer/Explanation:
Types of reproductive isolation include: temporal, ecological, mechanical, and behavioural.
A snail with a flat disc-like shell will not be able to mate with a snail having a conical shell - this is an example of mechanical isolation, where the animals are physically unable to mate due to incompatible body shapes and sizes.
The reproductive organs of male bush babies do not match with the reproductive organs of females of other bush baby species. - this is another example of mechanical isolation, as the sexual organs will physically not allow reproduction between these species
The mating call of a cricket is not recognized by a cricket of other species - this is an example of behavioural isolation, which results from incompatible mating rituals. I.e. the animals do not respond to each others mating behaviours
The signals sent by a male firefly are not recognized by the female firefly of other species. - this is also an example of behavioural isolation.
Temporal isolation is where species cannot interact because they do not have the same mating seasons or are not active at the same type of day. ?Ecological isolation occurs when two species do not come into physical contact to one another because they access different areas of the habitat. E.g. mating zones, food sources or nesting sites.
He wondered, Does the position of the pot determine the growth of the stem?<span>
He hypothesized that the plant’s stem grows perpendicular to the soil.
</span><span>To test his hypothesis, Brian placed the pot horizontally. He checked the plant after two weeks.
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<span>Brian observed that a plant’s stem grows against gravity.
</span><span>On analysis, Brian found that the plant grew parallel to the soil. He modified the hypothesis, and then retested the experiment.
</span><span>Brian communicated the results to his science class.</span>
Answer:
A person standing on the ground is barely affected by surface gravity
