Guia 12 Reproduccion

Prévia do material em texto

Guía de Aprendizaje 12. Reproducción (cap 43)
1. RECAP 43.1. Most animals reproduce sexually, but many can also or can only reproduce asexually, through budding, regeneration, or parthenogenesis. 
a. Explain why asexual reproduction might be disadvantageous for an animal living in a changing environment. See p. 881 
b. How is parthenogenesis related to sex determination in honey bees? See p. 881 
2. RECAP 43.2. Sexual reproduction involves gametogenesis, mating, and fertilization. Fertilization can be external or internal and involves mechanisms for ensuring that only one sperm from the right species enters the egg. 
a. Describe the steps by which a sea urchin sperm penetrates the egg. See Figure 43.4 
b. Explain how polyspermy is prevented and why it is crucial to do so. See pp. 886-887 and Figure 43.4 
c. What reproductive adaptations made life on land possible? See p. 888 
3. RECAP 43.3. The reproductive systems of men and women produce gametes and hormones, and these functions are controlled by hypothalamic and anterior pituitary hormones. In women, the hormonal control of reproductive functions produces linked ovarian and uterine cycles. 
a. Describe the path the human sperm and ovum take in moving from their respective gonads to the point at which fertilization occurs. See Figures 43.8 and 43.11 
b. In males, increased production of GnRH at puberty stimulates the release of what two hormones of the anterior pituitary? What effect do these hormones have? See p. 892 
En los hombres las dos hormonas de la hipofisis anterior que estan presentes en el aumento de la produccion de GnHR en la pubertad son: la hormona luteinizante (LH) y la hormona foliculo estimulante (FSH).
En la LH vemos como esta actua sobre las celulas de la leydig presentes en los testiculos, estimulando la produccion y secrecion de testosterona, la cual, es escencial en el desarollo y mantenimiento de los caracteres secundarios del genero masculino como lo seria: el crecimiento del vello corporal, la profundización de la voz, el crecimiento de los músculos, y la producción de esperma.
Por otra parte la FSH suele verse actuando en los testiculos, precisamente, en las celulas sertoli dando paso a la estimulacion de produccion de las proteinas escenciales para la espermatogenesis, tambien la produccion de inhibina B, una hormona que actua como una retroalimentacion negativa sobre la hipofisis anterior, inhibiendo la liberacion de FSH y regulando la espermatogenesis.
c. Explain the events in the ovarian cycle that result in release of a single ovum each month. What events prepare the uterus to receive the egg? See Figures 43.12 and 43.13 
4. RECAP 43.4. Controlling fertility is an important aspect of modern human life. Decreasing the probability of pregnancy is achieved through methods that prevent sperm and egg from meeting and from preventing implantation. Pregnancies can be facili- tated through medical technology. 
a. Which method of contraception is the only one to offer protection against sexually transmitted diseases (STDs)? See Table 43.1 
b. Explain what a couple who are both carriers of a genetic dis- ease could do to ensure that their offspring would not have the disease. See p. 899
5. Del video de Reproduccion asistida y sus insumos, hagan un mapa de conceptos de cómo son los procedimientos alli explicados.
a. https://javeriana.hosted.panopto.com/Panopto/Pages/Viewer.aspx?id=c8fca103-3dc6-478d-be63-ac2800fe12df
i. https://www.youtube.com/watch?v=KNofQio1HJs&feature=youtu.be
ii. https://emedicine.medscape.com/article/273415-overview#a1
iii. En Colombia: https://web.gencellpharma.com/trisonim-2/
6. Del siguiente video, planteen una hipótesis de cómo pudo haber sido la evolución del comportamiento sexual en los primeros Homo sapiens: 
 The evolution of human mating = 
 https://www.youtube.com/watch?v=OXQwtTOnLvg