Loop of Henle (reabsorption) The epithelial wall of the loop of Henle's descending arm is freely permeable to water, but is not permeable to salts. Notice that the osmolarity of the interstitial fluid increases from the cortex to the inner medulla, due to increasing concentrations of NaCI and urea. (Note: osmolarity describes the total concentration of solutes in a solution.) > As the filtrate moves down the loop of Henle, what moves across the walls of the nephron and in which direction (in/out of nephron)? Is this the result of passive or active transport? Explain, with reference to permeability and osmolarity. The thinner segment of the loop of Henle's ascending arm is freely permeable to salts, but not permeable to water. >What moves across the walls of this segment of the nephron, and in which direction? Is this the result of passive or active transport? Explain. The thicker segment of the loop of Henle's ascending arm is still impermeable to water, but NaCl is actively transported out of the filtrate as it passes through this segment. ? Why is it necessary for NaCl to be actively transported out of the nephron? In other words, why can't it diffuse out?
Show transcribed image textLoop of Henle (reabsorption) The epithelial wall of the loop of Henle's descending arm is freely permeable to water, but is not permeable to salts. Notice that the osmolarity of the interstitial fluid increases from the cortex to the inner medulla, due to increasing concentrations of NaCI and urea. (Note: osmolarity describes the total concentration of solutes in a solution.) > As the filtrate moves down the loop of Henle, what moves across the walls of the nephron and in which direction (in/out of nephron)? Is this the result of passive or active transport? Explain, with reference to permeability and osmolarity. The thinner segment of the loop of Henle's ascending arm is freely permeable to salts, but not permeable to water. >What moves across the walls of this segment of the nephron, and in which direction? Is this the result of passive or active transport? Explain. The thicker segment of the loop of Henle's ascending arm is still impermeable to water, but NaCl is actively transported out of the filtrate as it passes through this segment. ? Why is it necessary for NaCl to be actively transported out of the nephron? In other words, why can't it diffuse out?
1) Which of the following is a component of a vertebrate kidney? (Select all correct choices.)
glomerulus
Bowman's capsule
renal tubules
collecting ducts
Malphigian tubules
2)
In organisms, the ability to control osmosis depends on the properties of the plasma membranes of individual cells. Based on their ability to permit the free movement of water and some solutes, these membranes are best described as: (select all correct choices)
impermeable.
permeable.
semipermeable.
diffusible.
impervious.
3)I selected cortex; inner medulla, it was wrong.
The loops of Henle create a concentration gradient in the interstitial fluid surrounding the loop, with the concentration highest in the ____________ and lowest in the ____________ of the kidney.
inner medulla; cortex
outer medulla; inner medulla
outer medulla; cortex
cortex; inner medulla
cortex; outer medulla
4)
The main solutes in the filtrate as it enters the distal convoluted tubule are: (select all correct choices)
urea.
electrolytes.
other wastes.
amino acids.
nucleotides.
5) Ensure all correct choices are selected, for this question I only selected osmosis and it was wrong,
Water moves by: (select all correct choices)
random molecular motion.
active transport.
passive transport.
osmosis.
facilitated diffusion
6)
Compared to sexual reproduction, asexual reproduction: (select all correct choices)
requires less investment in attracting mates.
allows much more rapid population growth.
is rarely found as the sole mechanism of reproduction.
results in the production of genetically identical cells or individuals.
involves meiosis and fertilization as core processes.
7)
A key difference between hormonal regulation of the reproductive systems of males and females is that:
LH and FSH are released only in females.
LH and FSH are released only in males.
LH and FSH are released cyclically in females but nearly continuously in males.
LH is released in males and FSH is released in females.
LH is released continuously in males and FSH is released cyclically in females.
8)
True or false: In response to LH and FSH, ovaries secrete estrogen and progesterone.
true
false
9)
During the luteal phase of the menstrual cycle, if the oocyte is not fertilized, a number of events occur which are listed below. Select the answer that places the events in the correct chronological order.
Events: 1. the lining of the uterus is shed 2. the corpus luteum secretes progesterone 3. follicle cells are converted to the corpus luteum 4. the corpus luteum degenerates 5. estrogen and progesterone levels fall
3, 2, 4, 5, 1
1, 2, 3, 4, 5
2, 4, 3, 1, 5
4, 3, 2, 1, 5
5, 2, 3, 4, 1
10)
If an antibody is missing its Fc fragment, what would happen if this antibody encounters its target antigen in the bloodstream? Select all correct choices.
The antibody would be able to bind the antigen at a specific epitope.
The antibody would be able to bind the antigen, but not at an epitope site.
The antibody would not be able to bind to the antigen.
The antibody would be able to activate components of the complement system.
The antibody would not be able to activate components of the complement system.
11)
If an individual carries a mutation that results in a complete lack of MHC class I proteins, how would the individualâs immune response be affected? Select all correct choices.
Memory cell antibodies would not be able to attach to antigen epitopes.
Cytotoxic T cells would not be able to target (and destroy) infected cells.
Helper T cells would not be able to interact with antigen-presenting cells.
Plasma cell antibodies would not be able to attach to antigen epitopes.
12)
Which of the following statements is true regarding T cell receptors? Select all correct choices.
They recognize antigen-MHC complexes.
They contain variable and constant regions.
They are composed of two heavy (H) chains and two light (L) chains.
They are formed by the rearrangement of V, J, C, and D gene segments.
They can be found in the bloodstream independent of T cells.