Gen Bio 2 Exam 4 Study Questions

Front 1

1.How many of the following statements are TRUE regarding the inflammatory response?

a. Platelets release blood clotting proteins near the wound
b. Mass cells at the site secrete factors that constrict blood vessels away from the wound and dilate them at the wound
c. Neutrophils arrive and begin removig pathogens by phagocytosis.
d. The inflammatory response continues until all foreign material is eliminated and the wound is repaired.
e. Cytokines are a type of chemokine.

Back 1

4

Front 2

2.The cell mediated response…..

a.initiates when a cytotoxic T cell makes contact with the virus-infected cell and releases granules that cause the cell to self destruct.

b.involves antibodies that coat free virus particles so they cannot bind to the host cells’ membrane. The antibody coated virus is recognized, phagocytized and destroyed by a neutrophil or macrophage.

c.uses helper T cell that coat the virus and tags it with MHC II antigens. The virus is then engulfed by phagocytes and macrophages.

d.Utilizes B cells that alert cytotoxic T cells, which then release chemokines. Macrophages arrive and destroy infected cells.

Back 2

a

Front 3

3.Which of these is true about innate responses

i. Innate immune system responds the same way to every antigen.

ii. The innate response changes over time.

iii. The innate response is non-specific.

iv. Histamine is a key signaling molecule in the system.

Back 3

3

Front 4

4.What causes an inflammatory response?

a.Blood clots

b.A virus o the surface of the skin

c.A break in the skin that allows bacteria to enter the body

d.None of the above.

Back 4

c

Front 5

What is the order of antigen presentation?

1.Peptide broken into bits

2.peptide pieces bind to MHC-1 protein on ER

3.antigen is ingested

4.antigen is presented

5.MHC- peptide complex is transported to the surface

Back 5

3,1,2,5,4

Front 6

6.What is the difference between an epitope and an antigen?

a.An epitope is any foreign substance; an antigen is a foreign protein.

b.An epitope is the part of an antigen where an antibody or lymphocyte receptor binds.

c.An antigen is the part of an epitope where an antibody or lymphocyte receptor binds.

d.Antigens are recognized by B cells and antibodies; epitopes are recognized by T cells.

Back 6

b

Front 7

8.Which is true about the propagation action potentials

i. Sodium channels open quickly after depolarization

ii. The opening of the sodium channel is an exaple of negative feedback

iii. If a action potential starts in the middle of an axon it will go both way

iv. During depolarization, potassium channels open after a slight delay

v. Myelin sheathes increase propagation rate down the axon

Back 7

4

Front 8

9.Put the steps of the release of a neurotransmitter in the correct order:

1. Ion channels open when neurotransmitters bind and ion flow causes change in post-synaptic cell potential

2. Action Potential arrives and triggers the entry of Ca+

3. Synaptic vesicles fuse with pre-synaptic membrane and release neurotransmitters

4. Ion channels close as NT’s are broken down or taken back up by pre-synaptic cell

Back 8

2,3,1,4

Front 9

10.The ( ) create(s) a/an ( ) around the axon, which keeps Na+/K+ ions from leaking across the membrane
a.myelin sheath, insulation layer
b.Node of Ranvier, action potential
c.Schwann cells, action potential
d.glial cells, insulation layer

Back 9

a

Front 10

11.Which of the following statements about chemical synapses are valid?
a.They are more numerous than electrical synapses.
b.They are slower than electrical synapses
c.They are structured with a complete separation between the presynaptic and postsynaptic cells.
d.Only two of the above statements are valid.
e.All three of the first three statements are valid.

Back 10

e

Front 11

12.Which of the following is an activity related to the parasympathetic nervous system?

i. Inhibits release of stored glucose
ii. Slows heartbeat
iii. Causes release of epinephrine (adrenaline)
iv. Stimulates saliva release
v. Inhibits activity of the intestines.

Back 11

3

Front 12

13.Place the following statements in the correct order regarding what happens when Ca2+ and an action potential are both present in a muscle cell.

1. Power stroke pulls actin toward the center of the sarcomere
2. The myosin binding site becomes available
3. Cross-bridge is broken
4. Myosin and actin form a cross bridge

Back 12

2,4,1,3

Front 13

14.Which of the below describe skeletal muscle?

a.1 or 2 nuclei, branched, non-voluntary, contains myofibrils
b.multimucleated, unbranched, involuntary, no myofibrils

c.1 nucleus, unbranched, involuntary, no myofibrils

d.multinucleated, unbranched, voluntary, contains myofibrils

Back 13

d

Front 14

16.The following 4 statements concern detection of taste in humans:

i. A taste “bud” contains about 100 individual taste receptor cells of various types.
ii. Na+ channels are primarily involved in sensation of saltiness
iii. Increased influx H+ ions cause a hyperpolarization of taste cells in response to sour.
iv. From an evolutionary perspective, the ability to detect many bitter compounds could increase a population’s fitness.

Back 14

3 are correct

Front 15

17.Which sensory receptor is paired with its proper function

i. Nociceptors: sense harmful stimuli
ii. Chemoreceptors: respond to distortion caused by touch or pressure
iii. Mechanoreceptors: perceive specific molecules or classes of molecules
iv. Photoreceptors: respond to particular wavelengths of light
v. Electroreceptors: detect electric fields

Back 15

3 are correct

Front 16

18.Which is true about rods and cones?

i. Rods are for detecting dark/light, cones are for detecting color
ii. In the presence of light, the Na+ channel closes in rods.
iii. Rods are located facing the back of the eye, while cones face the front
iv. Rods and cones contain stacks or membranes.

Back 16

3 are correct

Front 17

Which of the following statements are true?

i. Autocrine signals act on neighboring cells.
ii. Neurotransmitters diffuse a short distance between neurons.
iii. Paracrine signals act on neighboring cells.
iv. Pheromones are released into the environment and act on the same individual that released them.
v. Neuroendocrine secretions are carried by the blood and act on distant cells.

Back 17

3 are true

Front 18

20.Hormones that are derived from the molecule cholesterol are lipid soluble, and therefore pass easily into the cell where they have their actions. Which of the following hormones are derived from cholesterol?
a.Testosterone
b.Oxytocin
c.Cortisol
d.ADH
e.More than one of the above is derived from cholesterol.

Back 18

e

Front 19

21.Antidiuretic hormone is manufactured in the
a. Anterior Pituitary
b. Posterior Pituitary
c. Hypothalamus
d. Collecting Duct
e. None of the above

Back 19

c

Front 20

22.What is signal transduction?

Back 20

d. The production of a second chemical messenger inside a cell in response to the binding of a hormone at the cell surface

Front 21

23. Which one of the following would occur if a person had a defect that resulted in the stopping of cortisol release?
a. ACTH would be constantly produced and released
b. ACTH release would be completely turned off
c. ACTH would not stimulate the Adrenal gland to produce cortisol
d. The hypothalamus would turn off ACTH release

Back 21

a

Front 22

24. In experiments where researchers suspect that a hormone may be responsible for a certain physiological effect, they may cut the neurons leading to the organ where the effect being studied occurs. What is the purpose of cutting these neurons?

Back 22

a.To make sure that the effect is not occurring through actions in the nervous system.

Front 23

25. Which of the following represents the correct sequence of events for sexual reproduction?

Back 23

b.meiosis → gametes → zygote → mitosis → embryo

Front 24

Which of the following structures in females is analogous (i.e., has the similar) function to the vas deferens in males?

Back 24

oviduct

Front 25

27. What is the most likely explanation for why Daphnia switch from asexual to sexual reproduction when certain environmental conditions deteriorate?

Back 25

d. Sexual reproduction creates individuals that are more genetically diverse, thus increasing the likelihood of some members surviving hard times.

Front 26

29. On a submarine expedition to the ocean bottom, you discover a population of fish that uses a method of reproduction in which female offspring develop from unfertilized eggs. What type of reproduction is this

Back 26

parthenogensis

Front 27

30.Below are five reproductive structures and their definitions. How many of them are paired CORRECTLY with their functioning?

i. epididymis – maturation and storage of sperm
ii. placenta – maternal/fetal exchange organ
iii. Fallopian tube – site of normal embryonic implantation
iv. Prostate gland – secretes sugars and prostaglandins to assist sperm
v. cloaca – a opening to the outside used by the excretory and reproductive systems in some vertebrates.

Back 27

3 are correct

Front 28

1)The membrane potential becomes less polarized when…
I - when all the Na+ flows in
II – When K+ flows out
III – during depolarization phase
IV – the membrane becomes less negative

Back 28

Correct answer is C three are right (I, II, III)

Front 29

2) Synapses can be…
I – excitatory
II – inhibitory
III – modulatory
IV – all of the above

Back 29

Correct answer is D all four are right

Front 30

3) Which of the following controls the skeletal muscles?
A – autonomic nervous system
B – Somatic nervous system
C – sympathetic nervous system
D – parasympathetic nervous system

Back 30

b

Front 31

4) Which side of the brain controls the right ear?
A – Left Side
B – Right Side
C – Both
D – Neither

Back 31

a

Front 32

5) Which part of the brain controls homeostasis?
A – Diencephalon
B – Cerebrum
C – Cerebellum
D – Brain Stem

Back 32

a

Front 33

1) Where are ion channels that respond to pressure found?
A – hair cells
B – tongue cells
C – spleen cells
D – ear ossicles

Back 33

a

Front 34

2) Which of the following are correct parts of the ear?
I – Stapes
II – Cochlea
III – ammatidia
IV – Oval Window

Back 34

Correct answer is C three are correct (I, II, IV)

Front 35

3) Rods are sensitive to __________ light. Cones are stimulated by _________.
A – Bright; colors
B – Bright; dim
C – Dim; Bright
D – Dim; colors

Back 35

d

Front 36

4) Which of the following statements are true about myosin?
I – myosin head can bind to actin
II – The head region catalyzes the hydrolysis of ATP to ADP and a phosphate ion.
III – Is not the site active movement
IV – The head region contains both ATP binding site and actin binding site.

Back 36

Correct answer is C three are right (I, II, IV)

Front 37

1) What are mast cells?
A – forms a gradient that marks a path to the wound site
B – leukocytes that release chemical messengers
C – blood components that release proteins that form clots
D - Host cells

Back 37

b

Front 38

4) What are the macrophages
I – leukocytes
II – involved in the process of secreting signaling molecules
III – marks a path to the wound site
IV – engulfs antigens

Back 38

Correct answer is C three are correct (I, II, IV)

Front 39

5) What are Cytokines?
I – Attract other immune system cells to the site
II – Chemical messengers
III – stimulate bone marrow to make and release additional neutrophils and macrophages
IV – induce fever

Back 39

The correct answer is D all are correct.

Front 40

2) How many of the following statements are true about muscle?
i. skeletal muscle consists of unbranched multinucleate cells
ii. cardiac muscle consists branched cells
iii. smooth muscle is essential to the function of the digestive system
iv. cardiac muscle does not contain myofibrils

Back 40

3

Front 41

1) How many of the statements below are correct regarding the endocrine system?
i. thyroid stimulating hormone is produced in the pituitary gland
ii. prolactin stimulates mammary gland growth and milk letdown
iii. thyroxine promotes growth
iv. insulin decreases blood glucose

Back 41

3

Front 42

2) An important insight into the molecular mechanism of hormone action came when researchers found a distinctive DNA-binding region in the __________.

a) thyroid stimulating hormone
b) steroid-hormone receptor
c) follicle-stimulating hormone
d) growth hormone

Back 42

b

Front 43

4) All of these hormones are secreted by the anterior pituitary except:
a) ACTH
b) growth hormone
c) oxytocin
d) thyroid-stimulating hormone
e) all of the above

Back 43

c

Front 44

1.) What is the correct flow of information through the neurons?

a) dendrite, soma, axon hillock, axon
b) dendrite, soma, axon, axon hillock
c) soma, dendrite, axon, axon hillock
d) dendrite, axon, axon hillock, soma

Back 44

a

Front 45

2.) Which of the statements are true regarding resting neurons?
i. potassium leaves the cell along its concentration gradient
ii. the membrane is more permeable to K+
iii. the voltage gated ion channels are open in a resting neuron
iv. the resting neuron has a resting membrane potential of -70mV

Back 45

3

Front 46

The repolarization event results in the membrane briefly becoming ______ negative than the resting potential, a state called _________.

a) more, depolarization
b) more, hyperpolarization
c) less, depolarization
d) less, hyperpolarization

Back 46

b

Front 47

How many of the following receptors are found in humans?
i. mechanoreceptors
ii. chemoreceptors
iii. electroreceptors
iv. photoreceptors

Back 47

3

Front 48

2.) A sound wave reaches your ear. How do the sound waves travel?

Back 48

d) tympanic membrane, ear ossicles, oval window, cochlea

Front 49

Which of the following statements is/are true about a photoreceptor cell before stimulation?
i. cGMP-gated sodium channel is open
ii. cGMP-gated sodium channel is closed
iii. Rhodopsin is in the cis formation
iv. there is less nerotransmitter present

Back 49

2

Front 50

The covalent bonds in water are polar because oxygen and hydrogen differ in their ...

Back 50

electronegativity: oxygen has a partial negative charge and hydrogen has a partial positive charge.

Front 51

In ice, water molecules form a ...

Back 51

crystal lattice

Front 52

In acid–base reactions, a proton donor ( ) transfers a proton to a proton acceptor ( ).

Back 52

acid; base

Front 53

The structure of a protein can be analyzed at four levels:

Back 53

(1) Amino acid sequence
(2) Substructures called -helices and -pleated sheets
(3) Interactions between amino acids that dictate a protein’s overall shape
(4) Combinations of individual proteins that make up larger, multiunit molecules

Front 54

All proteins are made from just ( ) amino acids.

Back 54

20

Front 55

Amino acids polymerize to form proteins. Polymerization reactions ...

Back 55

require energy and are not spontaneous.

Front 56

What are interactions that determine the tertiary structure of proteins?

Back 56

1. Hydrogen bond between side chain and carboxyl oxygen
2. Hydrogen bond between two side chains
3. Hydrophobic interactions (van der Waals interactions)
4. Ionic bonds
5. disulfide bonds

Front 57

Proteins called_______ help proteins fold correctly in cells

Back 57

molecular chaperones

Front 58

________ reactions must absorb heat to proceed, but ______reactions release heat.

Back 58

Endothermic;exothermic

Front 59

Reactions tend to occur spontaneously if the products have lower potential energy and higher _______than the reactants

Back 59

entropy

Front 60

______occurs when a molecule causes a change in enzyme shape by binding to the enzyme at a location other than the active site.

Back 60

Allosteric regulation

Front 61

Carbohydrates have more free energy than CO2 because...

Back 61

the electrons in C–H bonds and C–C bonds are shared more equally and held less tightly than they are in C–O bonds.

Front 62

Glucose processing has four components:

Back 62

(1) Glycolysis
(2) Pyruvate processing
(3) Krebs cycle
(4) Electron transport coupled with oxidative phosphorylation

Front 63

ATP consists of ...

Back 63

three phosphate groups, ribose, and adenine

Front 64

In a redox reaction, the atom that loses one or more electrons is_____ , and the atom that gains one or more electrons is______ .

Back 64

oxidized; reduced

Front 65

Cellular respiration is a four-step process:

Back 65

(1) Glucose is broken down to pyruvate.
(2) Pyruvate is processed to form acetyl-CoA.
(3) Acetyl-CoA is oxidized to CO2.
(4) Compounds that were reduced in steps 1–3 are oxidized in reactions that usually lead to ATP production.

Front 66

Oxygen is the most effective electron acceptor because of its ______.

Back 66

high electronegativity

Front 67

Cells that do not use oxygen as an electron acceptor cannot generate such a large potential energy difference and cannot make as much ATP as cells that use ______.

Back 67

aerobic respiration

Front 68

______involve the breakdown of molecules and the production of ATP, whereas ________result in the synthesis of larger molecules from smaller components.

Back 68

Catabolic pathways ; anabolic pathways

Front 69

Each photon or wavelength has a specific amount of energy. _____ wavelengths (e.g., blue, ultraviolet) have more energy than ______ wavelengths (e.g., red, infrared).

Back 69

Shorter; longer

Front 70

Photophosphorylation results when _____.
A. a photon of energy is absorbed, resulting in phosphorylation of NAD+.
B. a chemical reaction transfers the phosphate from NADPH to ADP.
C. the electron transport chain of mitochondria synthesizes ATP by chemiosmosis.
D. ADP is phosphorylated by energy released when protons move from the thylakoid lumen to the stroma.

Back 70

D

Front 71

Which of the following statements is correct?
A. Photorespiration is an energy-requiring process that reduces the efficiency of photosynthesis.
B. Photorespiration does not occur in living plants because the structure of the chloroplast prevents oxygen from binding to rubisco.
C. Photorespiration takes place in the cytoplasm, and carbon fixation takes place in the chloroplast.
D. Photorespiration does not require energy, so it does not affect the efficiency of photosynthesis.

Back 71

A

Front 72

In plants that perform C4 photosynthesis, called C4 plants, carbon fixation and the Calvin cycle occur ....

Back 72

in separate types of cells.

Front 73

In plants that perform a type of photosynthesis called crassulacean acid metabolism (CAM), carbon fixation and the Calvin cycle are separated in time.

Back 73

These plants, which also live in hot, dry habitats, keep their stomata closed all day and open them only at night.

Front 74

The Z scheme models the interaction between photosystem I and photosystem II. What does the “Z” represent?

A. the electron carrier that transfers electrons from photosystem II to photosystem I
B. the changes that occur in potential energy of electrons as they move through the two photosystems
C. the process of photophosphorylation that occurs with the movement of electrons in the two photosystems
D. the electron carrier that replaces electrons lost from photosystem II

Back 74

B

Front 75

Which of the following statements about primary growth is correct?

A. It occurs only in the root system.
B. It occurs only in the shoot system.
C. It can occur throughout a plant’s life.
D. It always stops once a plant reaches maturity.

Back 75

C

Front 76

Which of the following best explains why fats, instead of carbohydrates, are used for long-term energy storage in animals?

a. Fats contain more energy, gram for gram, because they are amphipathic.
b. Carbohydrates contain less energy than fats do, because the larger number of O–H bonds in carbohydrates have lower free energy than the C–H bonds in fats.
c. Fats are easier to store because they are nonpolar.
d. Our ancestors ate more fats than carbohydrates, so we adapted to the storage of fats.

Back 76

b

Front 77

define meristems

Back 77

populations of undifferentiated cells that retain the ability to undergo mitosis and produce new cells.

Front 78

what is a typical habitat for carnivorous plants?

Back 78

bog

Front 79

if cells in the ______ are removed, roots will no longer repsond to gravity

Back 79

root cap

Front 80

In 2005, a spike was driven into the trunk of a tree 2 meters above the ground (the tree was 10 m tall). The spike was driven 10 cm into the tree, and 20 cm of it protruded from the bark. What will be true about the spike in 2050?

Back 80

Its height above ground level will be 2 meters

Front 81

Both sieve-tube members and companions cells are _____ at maturity, although sieve-tube members lack nuclei and many major organelles.

Back 81

alive

Front 82

Phloem loading and unloading by companion cells requires...

Back 82

the expenditure of ATP and a membrane transport system

Front 83

The pressure-flow hypothesis is the leading theory to explain the movement of sugars from sources to sinks in plants (translocation). According to the pressure-flow hypothesis, what is the energetic driving force for translocation?

Back 83

active transport of sucrose from source cells to phloem cells located near source tissues, which results in high turgor pressure at sources

Front 84

Macronutrients are the building blocks of nucleic acids, proteins, carbohydrates, phospholipids, and other key molecules required in relatively large quantities. They are:

Back 84

nitrogen (N), potassium (K), calcium (Ca), magnesium (Mg), phosphorus (P), and sulfur (S)

Front 85

Limiting nutrients are macronutrients that commonly act as limits on plant growth. They are:

Back 85

N, P, and K are often limiting nutrients

Front 86

Micronutrients are required in very small quantities. Rather than acting as components of macromolecules, they usually function as cofactors for specific enzymes. Examples include

Back 86

iron, zinc, boron, copper, and nickel

Front 87

what is the relationship between plants and mycorrhizae?

Back 87

This relationship is symbiotic, and because both organisms benefit, it is also mutualistic because mycorrhizae provide nitrogen and/or phosphorus to the plants in exchange for receiving sugar.

Front 88

some bacteria are able to absorb N2 from the atmosphere and convert it to ammonia, nitrates, and nitrites in a process called nitrogen fixation. What is one example of this?

Back 88

Rhizobia (Rhizobium species and close relatives) are found in nodules on the roots of legumes and provide the plant with ammonia in return for sugar and protection

Front 89

define phototropism

Back 89

Any directed movement by an organism toward light

Front 90

why do plants move toward blue light?

Back 90

Plants move toward blue light because it can drive photosynthesis.

Front 91

what is the blue- light receptor?

Back 91

The blue-light receptor is a pigment called PHOT1 that phosphorylates itself in response to blue light.

Once this receptor protein is phosphorylated, a phototropic response is initiated.

Front 92

what was the first plant hormone ever discovered and what was it responsible for?

Back 92

Went named this hormone―the first plant hormone ever discovered―auxin.

Auxin promotes cell elongation in the shoot.

Front 93

what is gravotropism

Back 93

Gravitropism is the ability of plants to move in response to gravity. Roots grow down and shoots grow up or out.

The ends of root tips have a protective root cap. This root cap contains cells that are important for regulating the gravitropic response.

Front 94

what are cytokinins

Back 94

Cytokinins are a group of plant hormones that promote cell division

In the absence of cytokinins, cells arrest at the G1 checkpoint in the cell cycle and cease growth.

Front 95

What are two types of hormones are responsible for initiating and terminating growth in plants in response to changes in environmental conditions?

Back 95

gibberellins stimulate growth, while abscisic acid (ABA) inhibits it.

Front 96

Two key observations can be made about plant growth regulators

Back 96

(1) A single hormone often affects many different target tissues. This means there can be an array of responses to the same cell-cell signal.
(2) In most cases, several hormones affect the same response. Hormones do not work independently―they interact with each other.

Front 97

The hormones involved in controlling plant growth in response to age or environmental conditions include auxin, gibberellins, cytokinins, ABA, and ethylene. Which of the following statements best summarizes how these plant growth regulators work?

Back 97

It is common for a single hormone to affect many different target tissues, and in most cases individual hormones interact with other hormones to effect a response.

Front 98

If a pathogen invades a plant, the plant mounts a defense called the hypersensitive response (HR). HR causes ....

Back 98

rapid and localized death of cells surrounding the site of infection, starving the pathogen.

Front 99

Once the HR is underway, the hormone salicylic acid (SA) is produced at the infection site. SA triggers ...

Back 99

a slower, more widespread set of events called systemic acquired resistance (SAR).

Front 100

what role do bile salts play in the digestion of complex fats?

Back 100

they emulsify lipids, meaning that large masses of fat molecules are broken into smaller masses

Front 101

niacin, folate, and thiamine are examples of which kind of nutrient?

Back 101

vitamins

Front 102

what is the cause of the vast majority of gastric and duodenal ulcers?

Back 102

a bacteria called Heliobacter pylori causes an infection which degrades the lining

Front 103

How is most carbon dioxide carried in the blood?

Back 103

as bicarbonate ions (HCO3-) in plasma

Front 104

the Bohr effect on the oxygen-hemoglobin dissociation curve is produced by changes in

Back 104

ph

Front 105

the partial pressure of oxygen in the air at high elevations is ______ than at sea level

Back 105

lower

Front 106

What are the photoreceptor cells in the vertebrate eye?

Back 106

Rods are very sensitive to dim light but not to colors.
Cones are much less sensitive to faint light but are stimulated by different wavelengths of light (colors).

Front 107

How Do Rods and Cones Detect Light?

Back 107

Rods and cones have segments packed with membrane–rich disks that contain large quantities of opsin.
Each opsin molecule is associated with a molecule of the pigment retinal to form rhodopsin.
Retinal changes shape when it absorbs a photon of light, leading to a change in opsin’s conformation.
This change, in turn, leads to a series of events that culminates in a different stream of action potentials being sent to the brain

Front 108

Human taste–sensing chemoreceptors are scattered around the mouth and throat, but most are clustered on the tongue in

Back 108

taste buds
Each taste bud contains about 100 taste cells that synapse to sensory neurons.

Front 109

The sensation of saltiness is primarily a result of _____ dissolved in food.

Back 109

sodium

Front 110

The thin filaments are composed of two coiled chains of the globular protein ______

Back 110

actin

Front 111

The thick filaments are composed of multiple strands of a long protein called _____.

Back 111

myosin

Front 112

How Does Relaxation Occur in muscles?

Back 112

Thin filaments contain proteins called tropomyosin and troponin.
They work together to block the myosin binding sites on actin. As a result, actin and myosin cannot slide past each other.

Front 113

Smooth muscle is ______, lacks myofibrils, and is often organized into thin sheets

Back 113

unbranched

Front 114

Cardiac muscle contains branched cells whose ends are connected via specialized regions called _________

Back 114

intercalated discs

Front 115

Neural signals are the chemical messengers called _______.

Back 115

neurotransmitters

Front 116

Most animal hormones belong to one of three chemical families: peptides and polypeptides, amino acid derivatives, and steroids. What makes steroids different from the rest?

Back 116

steroids are lipid soluble but polypeptides and amino acid derivatives are not.
Thus, steroids cross cell membranes much more readily than do other types of hormones.

Front 117

What is the primary role of cortisol during prolonged stress in humans?

Back 117

to ensure the continued availability of glucose for use by the brain

Front 118

Where is cortisol produced?

Back 118

cortisol is produced in the adrenal cortex

Front 119

How Are Hormones Involved in Homeostasis?

Back 119

antidiuretic hormone (ADH) increases the permeability of the kidney's collecting ducts to water so water is reabsorbed from the urine and saved

Aldosterone increases reabsorption in the distal tubules of the kidney.

Front 120

The posterior and anterior pituitaries are each is influenced by different populations of neurons in the hypothalamus.
These populations of hypothalamic neurons are called _________because they synthesize and release hormones.

Back 120

neurosecretory cells

Front 121

The ________pituitary is an extension of the hypothalamus.

Back 121

posterior

Front 122

What are some examples of hormones stored in the posterior pituitary?

Back 122

ADH aids in reabsorption of water by the kidneys
–Oxytocin helps induce labor and milk production in females

Front 123

What are some examples of anterior pituitary hormones?

Back 123

production of sex hormones and regulation of the menstrual cycle (ACTH, follicle–stimulating hormone, and luteinizing hormone)
–milk production (prolactin)
–production of thyroid hormones (thyroid–stimulating hormone)

Front 124

How do steroids affect changes in gene expression?

Back 124

Steroid hormone–receptor complexes bind to specific sites in DNA called hormone–response elements.
Gene expression begins when a regulatory protein such as a steroid hormone–receptor complex binds to the hormone–response element for that gene.

Front 125

the peptide hormones are not lipid soluble and cannot enter the target cell, they must bind to receptors on the cell surface which activates....

Back 125

signal transduction

Front 126

Epinephrine triggers a signal transduction cascade that includes ______ as a second messenger to amplify the signal

Back 126

cyclic adenosine monophosphate (cAMP)

Front 127

describe parthenogenisis

Back 127

In parthenogenesis, female offspring develop from unfertilized eggs.
These offspring are genetically identical to the mother.
If a species reproduces exclusively by parthogenesis, no males exist.

One species that reproduces by parthenogenisis is Daphnia

Front 128

Daphnia were shown to require three different cues from the environment to switch to sexual reproduction. These three cues are:

Back 128

crowding, low food availability, and short day lengths.

Front 129

Spermatogenesis is the formation of _____, and oogenesis is the formation of ______.

Back 129

sperm; eggs

Front 130

Most animals that rely on external fertilization live in ______ environments and tend to produce _______numbers of gametes

Back 130

aquatic; exceptionally large

Front 131

In _______ animals, the egg is laid outside the mother's body and the embryo develops in the external environment. It may or may not receive any parental care.

Back 131

oviparous

Front 132

In ______ species, the egg remains within the mother's body, and development takes place there. The embryo attaches to the female’s reproductive tract and receives nutrition directly from the mother.

Back 132

viviparous

Front 133

When _______ occurs, offspring develop inside the mother's body but are nourished by nutrient–rich yolk stored in the egg

Back 133

ovoviviparity

Front 134

The male sex hormone is _____ and the female sex hormone is ______.

Back 134

testosterone; estradiol

Front 135

Which Hormones Control Puberty in Mammals?

Back 135

Gonadotropin–releasing hormone (GnRH) released from the hypothalamus triggers release of luteinizing hormone (LH) and follicle–stimulating hormone (FSH) from the pituitary gland.
LH and FSH then trigger increases in testosterone and estradiol

Front 136

How Do Pituitary and Ovarian Hormones Change during a Menstrual Cycle?

Back 136

FSH levels are high during the follicular phase and low during the luteal phase
Estradiol surges during the follicular phase while progesterone surges during the luteal phase

Front 137

Estradiol exerts ________ on LH and FSH at low doses, but ______ at high doses

Back 137

negative feedback; positive feedback

Front 138

The pituitary hormone ______ is important in stimulating smooth–muscle cells in the uterine wall to begin labor

Back 138

oxytocin

Front 139

Mast cells secrete factors such as _____ that dilate blood vessels slightly farther from the wound, increasing the delivery of leukocytes and other blood components to the injured area.

Back 139

histamine

Front 140

Neutrophils and macrophages remove pathogens by ________, the engulfing and digesting of foreign particles

Back 140

phagocytosis

Front 141

The _______ continues until the foreign material is eliminated and the wound is repaired

Back 141

inflammatory response

Front 142

The four characteristics of the acquired immune response are:

Back 142

Specificity – antibodies and other components of the acquired immune system bind only to specific sites on specific antigens.

Diversity – the acquired response recognizes an almost limitless array of antigens.

Memory – The acquired response can be reactivated quickly if it recognizes antigens from a previous infection.

Self–nonself recognition – Molecules that are produced by an individual do not act as antigens, so the acquired immune system can distinguish between self and nonself

Front 143

The T–cell receptor (TCR) only binds to antigens that have been processed by other immune system cells and presented (displayed) on their cell membranes in a complex process called __________

Back 143

antigen presentation.

Front 144

People infected with the human immunodeficiency virus (HIV), for example, suffer a progressive loss of cells because HIV kills these cells and macrophages

Back 144

CD4+ T