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3 years ago

How has waste leaving a cell affected its surface area to volume ratio?

1 answer:

6 0

The important point is that the surface area to the volume ratio gets smaller as the cell gets larger and as volume increases, surface area to volume ratio decreases. The larger a cell, the less easily it can get rid of waste and it also has more trouble getting water, nutrients and gases in. That is why we do not see giant cells. Instead we see multiple cells in larger organisms.

One way to increase surface area is to flatten the cell. That is why red blood cells are flat discs, instead of spheres. Another way is elongation. That is why many bacteria are rod shaped, and why neurons are elongated. In fact, the human body relies on the same principle to adapt to climate. Long tall and lean folks with long arms and legs live in East Africa, because such shapes increase surface area to get rid of excess body heat to avoid heat strokes. Europeans and Asians adapted to cold climates, in contrast, have shorter arms and legs and rounder torsos to minimize surface area. to conserve body heat.

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Gene flow or migration is the transfer of alleles or genes from one population to another. Select the combination of facts that

Artemon [7]

Answer:

B is the right option: I. and III.

Explanation:

In the Fugate family, four children out of seven had a blue complexion. This means that four children expressing such genes that cause blue complexion. These traits are not very common means the family has some hereditary background. According to the doctor, the occurrence of the condition is rarely seen that explains blue complexion does not appear due to environmental change or traveling.

6 0

3 years ago

Read 2 more answers

Define embryonic stem cells. Explain the pros and cons of Embryonic Stem Cells

just olya [345]

Answer:

Embryonic stem cells are pluripotent stem cells derived from the inner cell mass of a blastocyst, an early-stage pre-implantation embryo. Human embryos reach the blastocyst stage 4–5 days post fertilization, at which time they consist of 50–150 cells.

Explanation:

Adult Stem Cells

Embryonic Stem Cells

Induced Pluripotent Stem Cells

Pros

Trans differentiate and and reprogramming of these cells is possible but is not well studied

Thought to be less likely to be rejected if used in transplants

Success has already been demonstrated in various clinical applications

Can maintain and grow for 1 year or more in culture

Established protocols for maintenance in culture

ESCs are pluripotent cells that can generate most cell types

By studying ESCs, more can be learned about the process of development

Abundant somatic cells of donor can be used

Issues of histocompatibility with donor/recipient transplants can be avoided

Very useful for drug development and developmental studies

Information learned from the “reprogramming” process may be transferable for in vivo therapies to reprogram damaged or diseased cells/tissues

Cons

Limitations on ASC ability to differentiate are still uncertain; currently thought to be multi or unipotent.

Cannot be grown for long periods of time in culture

Usually a very small number in each tissue making them difficult to find and purify

Currently there is no technology available to generate large quantities of stem cells in culture

Process to generate ESC lines is inefficient

Unsure whether they would be rejected if used in transplants.

Therapies using ESC avenues are largely new and much more research and testing is needed

If used directly from the ESC undifferentiated culture prep for tissue transplants, they can cause tumors (teratomas) or cancer development

Methods for ensured reproducibility and maintenance, as differentiated tissues are not certain.

Viruses are currently used to introduce embryonic genes and has been shown to cause cancers in mouse studies

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3 years ago

- For plants and other organisms to develop differences among their respective species the alleles of their genes must contain

andre [41]

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

#LearnWithBrainly

5 0

3 years ago

Read 2 more answers

1. is the force that pulls objects towards Earth.

adelina 88 [10]

The answer would be “D,” as gravity is the force that keep all objects on Earth’s surface.

6 0

3 years ago

Which of the following situations would someone who advocates for animal rights prefer?