Mastering biology
Sunday, April 20, 2014
MB:Body Systems Regulation of prolactin in lactating mammals
MB:Body Systems Endocrine Glands in the Human Brain
MB:Body Systems Diabetes: Disrupting blood glucose homeostasis
MB:body systems Controlling Blood Glucose Levels
MB:Body Systems Maintaining Homeostasis
Monday, April 14, 2014
MB: Digestion Fat absorption in the Small Intestine
MB: Digestion. Reviewing Fat Structure
Sunday, April 13, 2014
MB: Reproduction Scientific Skills Exercise
Part A -
Understanding the experimental design
In this experiment, scientists inferred how something works normally based on what happened when the normal process was blocked.
What normal process was blocked in Jost's experiment?
hormone production by the embryo’s gonads during development
Part B
Normally, the gonads of a developing embryo produce hormones during development. How did Jost block this process?
Jost removed the portion of each embryo that would form the gonads.
Part C -
Interpreting the data
From Jost's results, what can you infer about the role of the gonads in controlling the development of mammalian genitalia?
In the absence of a signal from the male gonads, all embryos develop as female, regardless of whether they are genetically male (XY) or female (XX).
Part D -
Eliminating alternative hypotheses
The data in Jost's experiment could be explained if some aspect of surgery
other than gonad removal
caused female genitalia to develop.
If you were to repeat Jost's experiment, how might you test the validity of this alternative hypothesis?
Perform a sham surgery on some embryos. For example, open the embryo but do not remove the gonads.
Part E -
Making a prediction
What result would Jost have obtained if
both
male and female genital development required signals from the gonads?
None of the embryos that had surgery would have developed normal, sexually differentiated genitalia.
Part F -
Designing a follow-up experiment
Jost's experiment showed that the development of male genitalia requires some signal from the male gonads during embryonic development. But is this signal a hormone?
To test the hypothesis that the signal is the hormone testosterone, which of the following experiments should you perform?
Remove the embryonic gonads and replace them with another source of testosterone.
Part G
You test the hypothesis that the development of male genitalia normally requires testosterone from the embryonic gonads. You do this by removing the gonads of male (XY) embryos and replacing them with a crystal of testosterone.
Which of the following results would support your hypothesis?
Male genitalia develop in the rabbits.
MB: Reproduction Word Roots Part B
MB: Reproduction Word Roots
MB: reproduction Preventing Pregnancy
MB: reproduction Sex Hormones and Mammanlian Reproduction
MB: Reproduction. Sex Hormones and Mammalian Reproduction
Secondary Sex Characteristics
Males
deep voice, male hair growth pattern, increased muscle size, increased aggressiveness
Females
enlarged breasts, fat deposition in hips and breasts, water retention, changes in calcium metabolism and bone deposition
MB:Reproduction. Interpreting Data: Female Reproductive Cycle Hormones
Part A
What does the
x
-axis of this graph represent?
days since the start of the last cycle
Part B
What does the
y
-axis in the top panel represent?
levels of pituitary hormones
Part C
A surge in which hormone(s) immediately precedes ovulation?
LH and FSH
Part D
Based on the graph, elevated levels of which hormone(s) most likely stimulate the LH/FSH surge just before ovulation?
estradiol
Part E
The levels of pituitary hormones never increase above 10 grams/L of blood.
Cannot be determined from the graph
Part F
A surge in estradiol levels correlates with a surge in progesterone levels.
Not supported
Mastering Biology Immune System Part C
Mastering Biology Immune Systems Part B
Mastering Biology Immune System Part A
Newer Posts
Home
Subscribe to:
Posts (Atom)