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Pick either Peak and Decline Model or Life Span Developmental Model and describe a biological process that can support that theory or model. Be specific about the process and then the outcome that would explain the chosen theory.

All I know about aging in general and the aging of the brain, in particular, supports the first theory. With aging, reaction time slows down, and intelligence may decline significantly (although there is still a chance that it will be steady for the whole lifespan). It is explained by the...

a. Monocytes are powerful phagocytes. b. Skeletal muscle fibers do mechanical work. c. Goblet cells secrete mucus. In each of these 3 cases, decide which cellular organelle(s) must be present in great abundance in order to accomplish the functions described and indicate how these organelles are involved.

a. Monocytes are powerful phagocytes The cellular organelles that must be present in abundance for this function are phagosomes. Phagosomes work by forming a membrane that engulfs the foreign object to be phagocytosed. The resultant phagosome fuses with lysosomes that contain digestive enzymes, which finally digest the foreign body and...

A student working independently in the laboratory extracts a drop of blood from his finger and places it on a microscope slide in a drop of distilled water. He adds a cover slip, puts the slide on the microscope, and focuses in on high power. To his surprise, he sees nothing. Only a red haze fills the field of view. Explain why no RBCs are visible.

No red blood cells were seen under the microscope when a drop of blood was placed in distilled water. This observation can be explained by the fact that distilled water is a hypotonic solution with respect to the inside of the red blood cells. Therefore, the cells absorbed water via...

Select and summarise one original research paper in the area of developmental biology. Include some description of experimental methods and results.

Intra-organ communication is necessary for the growth and development of organs. Biochemical signalling is involved in communication in the heart through molecules such as BMPs, Wnts, FGFs. Conversely, cell-to-cell communication occurs through the Ephrin, Notch, or Neuregulin/ErbB2 pathways. However, the mode of communication that synchronizes the growth of the endocardium...

Compare and contrast the production and therapeutic uses of Embryonic Stem Cells (ESCs) and Induced Pluripotent Stem Cells (IPSCs). Evaluate their potential clinical benefits and any disadvantages, considering ethical, regulatory and technical aspects.

Production ESCs are formed from a human embryo using the undifferentiated internal mass of cells. In contrast, IPSCs are produced from the reprogramming of different types of somatic cell types from diverse animal species.Both types of stem cells are pluripotent, meaning that they can differentiate into products of the three...

With the aid of suitably-labelled diagram(s), describe the environmental factors and intrinsic signals that regulate stem cell niche behaviour in adult hair follicles.

Environmental signals constitute tissue activities that regulate stem cell activity. Epidermal injury is the key environmental signal. Bulge cells act quickly after injuries to the epidermis by producing short-lived cells that move to the center of the lesion. This process promotes healing. Intrinsic signals include a protein-rich diet, which promotes...

With the aid of suitably-labelled diagram(s), discuss the interactions between the key signalling pathways involved in the embryonic development of an organ of your choice (excluding the limb bud).

The vertebrate eye originates from the frontal neural plate, the ectoderm of the head surface and mesenchyme drawn from the neural crest. There is a need for proper synchronization of ocular tissues to guarantee the formation of a functional eye. The frontal neural plate gives rise to the single central...

Describe the key elements of embryonic limb development in each of the three axes. Include descriptions of the signalling molecules and the underlying mechanisms determining where, when and how limbs develop after the limb bud is established.

The three axes of limb development are proximodistal, dorsoventral and anteroposterior. The proximodistal axis phase refers to the development of the limb from its tip to where it connects to the body. The apical ectodermal ridge (AER) is first formed at the region where FGF10 (fibroblast growth factor 10), which...

Give the definition of a morphogen in biology, and briefly explain the principles underpinning its general role and mechanism of action in embryonic development.

A morphogen is a signalling substance that influences the arrangement of tissue development in a process known as morphogenesis. Morphogens act directly on cells to bring about a characteristic shift in their development. However, they act at a distance from their source of production. The magnitude of their effect is...

Use brain plasticity (neuroplasticity) to explain how an older man can start to develop a growth mindset. What can he do to actually change his brain so that he can adopt a growth mindset approach?

To change his mindset, an older man needs to look at the situation from a different perspective. The man might tell himself that although he is not ready for the test yet, reading and preparing for it will certainly increase his chance of passing. It is very important to stop...

Briefly describe conception as a development concept, why it is interesting or made an impact on you, and how you might use this development concept in your family life or career.

The process of conception is a highly regulated and intricate topic, which makes it more interesting to explore and study. Ovum fertilization is carried out in the fallopian tube. The egg is surrounded by many sperm cells, each of which wants to penetrate it, but only one succeeds. In this...

What are areas of the brain considered the cortical motor circuit?

The areas of the brain considered the cortical motor circuit are the primary motor cortex, Premotor area (PMA), which guides body movements through linking sensory information, and by controlling the muscles which are nearest to the body’s major axis and the supplementary motor area (SMA), which is involved in the...

What is a ballistic movement, and how is it produced?

A high-velocity musculoskeletal movement such as tennis serves or boxing punch requires reciprocal coordination of agonistic and antagonistic muscles. It is produced when the body parts are not able to execute the right action in response to the neurological command.

What is a neuromuscular junction?

The neuromuscular junction is the region of contact connecting the ends of myelinated nerves and a skeletal muscle fiber. The body has close to over 600 skeletal muscles of various kinds, and each comprises numerous muscle fibers. The length of the skeletal muscle ranges from a few millimeters to some...

What is meant by the term “ecosystem services”? Make a list of ecosystem services that are provided by forests in the Pacific Northwest. Which ecosystem services could be construed as a tragedy of the commons?

Ecosystem Service is referred to as the combination of economic, ecological, as well as social factors needed to sustain and improve the quality of the environment in order to make it best address the prevailing as well as future needs. For instance, the ecosystem services provided in the Pacific Northwest...

Riparian zones are naturally dynamic, so why should humans take pains to “restore” them? What are key factors to consider when doing riparian restoration? Illustrate your answer with at least one specific example.

Riparian Zones should mainly be restored as they are habitats for flora, fauna, and aquatic organisms. Moreover, the zones are known to prevent erosion and to protect the quality of water. During this process, it is vital to consider our understanding of riparian zone processes and the causes of the...

If you travel to central Oregon, you can find 30 million-year-old fossils that portray the forests that existed then were hardwoods that consisted of maple, willow, alder, ginkgo, sycamore, and others. How is the modern climate of Oregon different from that of 30 million years ago, and why does it favor conifers?

The climate in central Oregon has dramatically changed over the years. This has mainly been attributed to increased human activity around the region that has to lead to global warming and a reduction of rainfall. As a result, the hardwood trees are mainly restricted to the areas near the streams....

Describe the fire history of the Willamette Valley during the past millennium – what caused these fires, and what was their effect on the landscape and the people who lived here? Can you put this into the context of Shifting Baselines?

During the past millennium in the Willamette Valley, the fire regimes were mostly influenced by both anthropogenic and natural causes. Human-set fires were transformed by regional climate unpredictability during the medieval climate anomaly as well as the Little Ice Age and mostly left the land bear. The reduction of the...

Kolb et al. distinguish between utilitarian and ecosystem definitions of forest health. a. Provide an example of a utilitarian definition of forest or ecosystem health. b. Kolb et al. go on to say that “a more useful definition of forest health from an ecosystem perspective” must contain two key aspects or features. What are these? c. Give a specific example of an ecosystem and at least one specific example of each of these features for that ecosystem.

a. A forest (or ecosystem) is healthy when it’s biotic, and abiotic aspects do not hamper the forest’s management objectives at any given time. b. Biotic features and abiotic features. c. An estuary is an example of an ecosystem. Its abiotic features include water and rocks, while its biotic aspect...

Removal of trees and other vegetation from streamside areas poses a variety of threats to salmon habitat. List three different effects that removal or loss of vegetation has on salmon habitat.

Destroying the vegetation can lead to the extinction of salmonids’ right habitat as no streams will emanate from the mountains to the estuaries which form their habitats. The destruction of the vegetation can also cause a breakdown of the ecological chain of the population. Salmon feeds on certain vegetations that...

a. Is there more or less dense forested area found in the Coburg Hills (adjacent to the Willamette Valley of today as compared with the landscape of 150 years ago? b. Individuals of what tree species are more abundant in the hills surrounding the Willamette Valley today? c. Individuals of what tree species are less abundant in the hills surrounding the Willamette Valley today? d. Are there more or fewer sloughs, oxbows, and side channels in the Willamette River today compared with that of 150 years ago? e. What major human influence accounts for the differences you have described? f. What is one important function that sloughs, oxbows, and side channels play in salmon ecology?

a. As compared to 150 years ago, the landscape of the Coburg Hills currently has a denser forested area. b. Today, the most common tree species around the Willamette Valley are the Pseudotsuga menzieshi. c. The less abundant tree species are Arbutus menziesi and Quercus garryana. d. There are fewer...

a. Name at least three physical characteristics of evergreen conifers in the Pacific Northwest that allows them in order to outcompete with the deciduous hardwood trees. b. Are there other factors (not related to the trees themselves) that allow conifers to outcompete hardwoods?

a. The trees are mostly characterized by needle-like leaves. The leaves are made in such form in order to reduce the surface area exposed to sunlight. A small surface area helps to prevent excessive evaporation. The trees are usually very large, providing a buffer against environmental stress.The trees usually have...

Why is it plausible that nonsentient natural entities such as mountains and valleys have some sort of intrinsic value? Why is it preferable to speak of their intrinsic value rather than of their moral rights?

Mary Anne Warren agrees with the premise that rivers and mountains have certain intrinsic value since they are important elements of the existing bio-system. They can be critical for the sustainability of various living beings, including humans. The author does not accept the idea that it is possible to speak...

Why do sentient nonhuman animals have certain basic moral rights?

Sentient non-human animals are supposed to have certain moral rights because they have the capacity to distinguish pleasure and pain. Moreover, they have the tendency to avoid painful experiences. In this case, the capacity to suffer is the main reason why a living being should be protected from harm. So,...

The facility you work for wants to pilot a program to allow parents to choose the sex of their child and has scheduled an open forum meeting for hospital staff and physicians. The physicians are in favor of this action and the staff is opposed. You were selected to speak for the staff and the topic is Genetic Modification of Human Beings: Is it Acceptable? How would you prepare for the forum and what information would you want to have? How would you utilize your critical thinking skills when asked questions?

The preparation for the forum about the issue of genome editing requires one to consider the topic from different angles. First of all, it is vital to address the health-related consequences of the sex selection procedure. According to Kang et al., CRISPR (clustered regularly interspaced short palindromic repeats) editing procedure,...

How does the effect of environmental factors on average longevity change over time?

The longevity over time significantly decreases due to the fact that the aging process affects almost all organelles. It is also associated with the accumulation in different parts of the cell of various aging agents. In aging tissues, the number of membrane organelles decreases, the volume of the rough endoplasmic...

Why do we age? Discuss biological theories of aging.

The process of aging is the result of continuous and gradual accumulation of DNA damage or mutations triggered by outside environmental factors and inherited features of an organism. One of the causes of aging and cell death is violations of DNA repair processes, leading to the emergence and accumulation of...

When is animal research ethical? a. Never, b. When steps are taken to ensure that the animal experiences minimal pain and suffering, c. When human lives can be saved as a result of the knowledge gained, d. When research is conducted at universities rather than by for-profit organizations. Please choose your answer and explain your choice as indicated by the directions by explaining your thoughts.

b. and c. The issues of research ethics remain extremely important for specialists related to different branches of science. The difference between appropriate and unethical approaches is rather obvious when it comes to dangerous experiments involving people’s participation. Still, the situation becomes more complicated when human participants are substituted by...

Do you think nature or nurture influences development more? In other words, do you think biological processes influence physical and mental growth across a lifetime or do you feel that our environmental surroundings affect this change? Give specific examples to support your claim and support your reasoning.

It has been long discovered that genes influence human behavior and health. However, it is also known that people’s environmental surroundings shape their development and health conditions. The extend of the influence of these two factors has been a perennial subject of debate for medical scholars and philosophers alike. I...

Find some old tennis balls or any type of object and try juggling two balls with one hand or three balls with two hands. Explain how muscle sense is involved in juggling.

The skill of juggling requires the coordination of several systems, including the muscular system, nervous system, and skeletal system. Muscle memory is defined as the pattern-like movement created by one’s body through learning to perform it afterward as if it was a familiar or normal activity. Muscle memory or sense...

Going out in the sun stimulates quite a bit of activity in the skin, especially on the hot summer day. Describe what is happening in the skin in response to sunlight.

The temperature of the body is regulated by the hypothalamus located in the brain. The hypothalamus accomplishes this by initiating changes to skin effectors, such as muscles in hair follicles and sweat glands. This is usually a complex process. The temperature receptors detect changes in the external environment pass this...

Stratified squamous keratinizing epithelium is an excellent barrier to pathogens in the epidermis of the skin. Despite the fact that it is such a good barrier, this tissue would not be suitable for the lining of the trachea or small intestine. Explain.

When the epidermis produces new cells, they are immediately pushed towards the outer part of the skin. During this process, their nutrients reduce as they are pushed far away from the basement membrane. The maturing cells go through a process of keratinization or hardening, during which the newly formed cells...

What are alveoli? What purpose do they serve?

Alveoli are small lung parts where oxygen is transferred to the blood and carbon dioxide is taken away. Three million alveoli in the lungs provide the body with oxygen.

Where do you stand regarding animal testing?

When it comes to animal testing, there is a definite resolution to the controversy. It is hard to take into account all variables necessary for making a decision. On the one hand, I agree with the view that modern technologies allow us to test products without the involvement of animals,...

What role does cellular respiration play in the water cycle? A) It removes H2O from the atmosphere during glycolysis. B) It removes H2O from the atmosphere during acetyl CoA formation. C) It releases H2O to the atmosphere during the citric acid cycle. D) It releases H2O to the atmosphere during electron transport.

It removes H2O from the atmosphere during glycolysis. Explanation: Cellular respiration is a process used by aerobes to process food by combining it with oxygen and diverting the resulting energy via the mitochondria. It is then stored using adenosine triphosphate (ATP), which fuels other processes. Glycolysis is the first step...

Damage to the frontal lobes of the brain is a likely result of A) consuming low doses of alcohol B) consuming medium doses of alcohol C) binge drinking alcohol D) chronic use of alcohol

D (chronic use of alcohol) is the correct answer to the question. Explanation: Continued alcohol consumption is known to cause a variety of health concerns that are less immediately harmful than ones stemming from alcohol poisoning, but also more challenging to address. It is defined as the drinking of liquids...

What can be the cause of weakened muscle and kidney functioning? A) Too little potassium. B) Too much potassium. C) Too little calcium. D) Too much calcium. Please select the best answer from the choices provided.

The correct answer is D (too much calcium) because while calcium is bone strengthening and essential for a healthy lifestyle, too much of it can lead to negative repercussions, as it builds up in the body. Explanation: These health effects can include the contamination of the urinary tract due to...

Which part(s) of the brain, when impaired by alcohol, play an important role in memory: a) Nucleus accumbens b) Hypothalamus c) Hippocampus d) All of the above

The correct answer is C (Hippocampus). Explanation: Hippocampus is an area of the human brain responsible for memory, both short- and long-term. After just one or two drinks, the function of the brain becomes damaged by alcohol, inhibiting most processes occurring in the hippocampus. Hippocampus also regulates spatial navigation, which...

Which approach is least effective in retrieving a dog who has managed to slip off its leash? a) Stop, drop and lie down. b) Run in the opposite direction. c) Crouch down into a ball and offer the dog treats d) Run after the dog while shouting its name

The correct answer is D (run after the dog while shouting its name). Explanation: A dog off-leash can be difficult to retrieve if you don’t know how to do it correctly. According to professional trainers, the least effective method is to chase the dog while shouting its name. This is...