BIOL30001 Lecture Notes - Lecture 7: Human Musculoskeletal System, Hypogonadism, Semen

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greymarten981

13 Aug 2018

School

University of Melbourne

Department

Biology

Course

BIOL30001

Professor

Mark Green

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Document Summary

Gnrh which works like gonadotrophins they found that it regulates the hpg axis if you knock out the gene for this peptin then you block puberty. 1ng to 100ng there is a lot of steroids produced during this period the steroid works on the morphological development, mental, behavioural. Organ systems involved in pubertal changes the whole body is involved this is refference picking the more relevant part. Adrenal system part of the neuroendocrine system complicated as well sexual hormones which is androgens. Dhea or it cand be dhea-s they are abundant but they are quite weak they have an effect in the musculanity it is not key for puberty but it provides the sign that puberty is on onset. Nervous system this is continuous you have mental maturation steroids act on the cns to mature the brain there is a greater feeling of independence. Why teenagers feel more independent than parents.

Related Questions

QUESTION SET 3

Sexual Selection, Developmental Thresholds, and Ornamentation

INTRODUCTION

In Chapter 10 you read about how sexual selection can drive the evolution of bizarre and sometimes costly ornamentation or weaponry in animals, often in males. This paper reveals a situation where sexual selection is the driver, but the result is more complex than might be expected at first glance. The authors describe some beetle species where different thresholds encountered as larvae result in different levels of ornamentation, and consequently different reproductive strategies.

The authors show that in one family of beetles (the Scarabeidae [dung beetles]), two different threshold mechanisms have independently evolved. Each of these thresholds has a different effect on horn development in the males of these beetles. Both mechanisms are triggered by body size in larvae. For one mechanism, if a larva attains the threshold size its adult morphology (the phenotype it will have after it pupates) switches from being hornless to being horned. The second threshold, also based on larval body size, similarly results in either having a short or a long horn (see Figure 2).

This discovery led the authors to look more closely at other beetle species where male polymorphism was known to occur, and they found two other examples where this double threshold mechanism was operating (see Figure 1). In the family Lucanidae (stag beetles), they found that male trimorphism was characterized by differences in the mandibles, with male mandibles exhibiting three increasing sizes moderated by the thresholds. In the family Curculionidae (weevils), the thresholds controlled the development of ventral body spines. Here, the beetles either lacked spines (and thus resembled females), had short spines, or had long spines.

The authors suggest that this multiple-threshold system may be more prevalent than previously thought, and anticipate more examples coming to light.

QUESTIONS

Question 1

What are polyphenic regulatory developmental mechanisms?

Answer:

Question 2

Can you think of an example of polyphenic regulatory developmental mechanisms besides the beetles mentioned in this paper.

Answer:

Question 3

The authors use the ârock-paper-scissorsâ analogy to describe the potential result of this two threshold system when it comes to reproductive success in dung beetles. As in the game of rock-paper-scissors, each possible pair-wise comparison has a clearly defined winner. Give a hypothetical example of what this might look like in the context of dung beetle mating success.

Answer:

Question 4

What is the difference between the systems described in this paper and the other examples of male trimorphism cited by the authors (in isopods, lizards, and birds)?

Answer:

Question 5

Why might a trimorphic system such as this evolve? Why wouldnât natural selection just drive all males to have the biggest possible horn, spine, or whatever the ornament involved is?

Answer:

Kindly write a one page summary of the data below.

A crucial assumption underlying most models of sexual selection is that sexual advertisements honestly reflect the phenotypic and/or genetic quality of their bearers (1). Here we show that experimental activation of the immune system is rapidly mirrored in the expression of a carotenoid-based secondary sexual trait in male blackbirds (Turdus merula). This result shows that sexual advertisement honestly signals male health and can be reliably used by conspecifics as a cue of individual quality during intra- and/or intersexual interactions. Male blackbirds exhibit a black plumage with a yellow to orange bill, whereas females are brownish with a brown bill. Recent studies have suggested that bill color is a sexually selected trait in blackbirds (2, 3). For example, resident male blackbirds are more aggressive to mounts with orange bills than to mounts with yellow bills (2). Bill pigmentation might therefore provide a signal used during contests between males (2). In addition, male blackbirds with orange bills are mated with females in better body condition and fledge more offspring than males with yellow bills (3). Overall, these results suggest a role for bill color in sexual selection, possibly as an indicator of male phenotypic quality. Carotenoids are common components of colored signals used in animal communication (4). They are also important in the up-regulation of various aspects of the immune functioning (5) and cellular protection against free radicals (6). This suggests that a trade-off may exist between allocation of carotenoids to sexual signaling versus immune defenses (4). Using an autosampler high-performance liquid chromatographer, we determined the presence of carotenoids deposited in the bill of male blackbirds [see note (S1)] (7). The analysis of the absorption spectrum revealed the presence of - and -carotene, -cryptoxanthin, zeaxanthin, and lutein (Fig. 1A). To investigate whether bill color reflects immune status, we immunized captive male blackbirds with a suspension of sheep red blood cells (SRBC) in both spring 1999 (n 19) and spring 2002 (n 13). A control group (n 15) was injected with a phosphate-buffered saline solution (PBS) for control in 2002. Only the 2002 birds were used as a direct test of the hypothesis that immune activation reduces the expression of the secondary sexual trait, by comparing changes in bill color for SRBC and PBS males. Birds immunized with SRBC in both years (n 32) were used to assess the effect of anti-SRBC immune response on bill color [see note (S2)] (7). The humoral immune response against SRBC was determined 7 days after the challenge with a haemagglutination technique. Birds immunized with SRBC displayed a significant decrease in bill color [repeated measurements analysis of variance, F(1,26) 14.34, P 0.0008; Fig. 1, B, C, and D], which was independent of initial bill color and was not associated with a decrease in body mass (P 0.1). In addition, among immunized males, the likelihood of becoming duller was significantly correlated with the intensity of the anti-SRBC response as determined from the haemagglutination test (logistic regression, Wald 2 5.12, P 0.023, n 32), whereas neither year nor initial bill color entered the logistic regression model (P 0.1). Overall, these results demonstrate the existence of a trade-off between sexual advertisement and immune activation in male blackbirds. This finding has important consequences for both the evolution of secondary sexual traits and the cost of immune function. Assessment of opponent quality during male-male competition or mate quality during female choice based on a dynamic trait, such as bill color, might have evolved if it honestly reflects health status of the individual (1). The activation of the immune system by an infectious process is rapidly mirrored in the color of the bill. Contrary to feather ornaments that are produced during the annual molt, dynamic traits might therefore convey a continual update on male health. Carotenoids, such as astaxanthin, lutein, and -carotene, used for sexual signaling have been shown to enhance in vitro and in vivo antibody production to SRBC (8) and to provide protection against free radicals (6). Our results suggest that the activation of the immune system withdraws carotenoids to enhance immune functioning as well as to deal with free radicals produced during the immune response, at the expense of sexual signaling.

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PLEASE ANSWER ALL QUESTIONS..PLEASE NOT ONLY 1 QUESTION. THANK YOU

QUESTION 1. Chronic diseases generally have several underlying characteristics, including a.A long latency period between exposure to risk and disease outcomes b. Low degree of preventability c. High curve rate d.None of the above

QUESTION 2.Which of the following risk factors collectively explain a significant proportion (not incidence) of most chronic diseases. a.Tobacco, alcohol, diet b.Tobacco, alcohol, diet, physical activity c. Alcohol, physical activity d.Tobacco, diet, physical activity

QUESTION 3.Adherence to treatment is influenced by several interacting dimensions including a.Social and economic factors b. Healthcare system factors c.Condition-related factors d.Therapy-related factors e.Patient related factors f.All of the above

QUESTION 4. _________ is the leading cause of cancer in both developed and developing countries worlwide a.Radiation exposure b. Tobacco use c.Pesticide exposure d.Air pollution

QUESTION 5.This week's YouTube video on treating non-communicable diseases in Rwanda showed how a community health worker helps to treat heart disease, diabetes and _______ a.Cancer b.Asthma c.Hepatitis d.HIV/AIDS

QUESTION 6.Which of these are myths of chronic disease control a.Benefits of chronic disease control accrue not only to the individual but also to the population b.Economic growth improves all health conditions c. Chronic diseases are associated with low SES/poverty d.Chronic disease only occurs in the elderly e.a and c f.b and d

QUESTION 7 ___________ remains the leading cause of death among both men and women in low- and middle-income countries a.Cancer b.Cardiovascular disease c. Diabetes d.Obesity e.Respiratory disease

QUESTION 8.Chronic disease in adults accounts for approximately 60% of all deaths worldwide. True False

QUESTION 9.The WHO's Innovative Care for Chronic Conditions Framework includes a positive policy environment. True False

QUESTION 10.It is estimated that the overall number of cancer cases will rise by 50% in the next 20 years. True False

QUESTION 11.Comorbidity refers to simultaneous occurrence in a person of two or more disorders; comorbid conditions can increase the risk of adverse outcomes. True False

QUESTION 12.Emerging evidence supports starting promotion efforts during pregnancy and early childhood and continuing efforts throughout life lower exposures to major chronic disease risk factors. True False

QUESTION 13. Increased cumulative exposure to risk factors over the lifecourse combined with social and economic inequalities, leads to the levels of inequalities seen in later adult life. True False

QUESTION 14.The "compression of morbidity" model proposes that morbidity due to aging cannot be postponed or mitigated by disease prevention programs True False

QUESTION 15.There is few significant funding sources for chronic diseases in low-and middle-income countries. True False

QUESTION 16.To combat chronic diseases, modern, evidence-based interventions emphasize shared decision making and collaborative goal setting among providers and patients. True False

QUESTION 17.In the absence of legislative, financial and engineering approaches, health education programs often have a limited impact on preventing or reducing chronic diseases. True False

QUESTION 18. It is estimated that deaths from diet-related chronic disease in China will triple between 1995 and 2025. True False

QUESTION 19.The third highest percent of global DALY's is attributed to which risk factor? a.Alcohol use b.Tobacco use c.Unsafe sex d.Childhood underweight

QUESTION 20.In the 1990's which country experienced a substantial decline in male life expectancy as a result of dramatic socio-political changes a.China b.Russia c. India d.Canada

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BIOL30001 Lecture Notes - Lecture 7: Human Musculoskeletal System, Hypogonadism, Semen

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