Ch 9, 10,11 Flashcards
0
Q
Define the term homeostasis?
A
Homeostasis is the ability of the body to maintain the condition of its internal environment to maintain stable condition
1
Q
Which is more variable: your external environment or the internal environment of your cells
A
Your external environment is more variable as your internal environment is constant due to homeostasis
2
Q
List three variables that are subject to homeostasis?
A
Temperature
Water
Blood Glucose
3
Q
What are the two major body systems responsible for maintaining homeostasis?
A
The endocrine (hormonal) and nervous systems are the major systems responsible for the control and coordination of homeostasis
4
Q
Distinguish between the central nervous system and the peripheral nervous system?
A
The brain and the spinal cord make up the Central Nervous System and all other nerve cells, in whole or part, that lie outside the central nervous system for the peripheral nervous system
5
Q
Distinguish between the sensory neuron and effector neuron
A
Effector neurons carry impulses away from the central nervous system to muscle cells
6
Q
Distinguish between axon and dendrite
A
Axon is extension of a nerve cell along which impulses are transmitted away from the cell
Dendrites are branched extensions of a nerve cell that transmit impulses to the cell
7
Q
Distinguish between receptor and effector organs
A
Receptors detect specific sensory information from the external environment eg soundwaves
Effector organs respond to the stimulus from the nerve
8
Q
List the major sense organs
A
Sight, hearing, smell, taste and touch
9
Q
List the five taste sensations
A
Sour, salt, sweet, bitter, umami
10
Q
What are the main glands involved in the endocrine system
A
- Hypothalamus
- Pituitary
- Thyroid
- Adrenals
- Pancreas
- Ovaries/ Testes
11
Q
List the events that occur in the human body if the core temperature threatens to drop below the set point of the hypothalamus
A
- ‘warming up’ mechanism activates
- motor Neurons relay messages
- skeletal muscles activated; shivering generates heat
- increased heat production
- body temperature rises
12
Q
Explain why evaporation of sweat is an important factor in maintaining a stable core temperature on a very hot day?
A
The evaporation of water requires heat that is provided by the body
13
Q
Explain how behaviour of an individual can contribute to maintenance of a stable core temperature
A
The way a person reacts to different weather conditions and levels of physical activity can contribute to maintenance of a stable core temperature
14
Q
What is the source of body heat for an ectotherm
A
Ectotherms expose as much of their body as they can to the sun
15
Q
Give one structural and one behavioural adaptation of a frog that enables it to survive in a cold environment
A
Some frogs and toads live underground during the winter to avoid freezing temperatures
16
Q
Many desert mammals have countercurrent systems leading to the brain? What is the purpose of such a system and it’s structure?
A
The purpose of a countercurrent system is to warm blood.
17
Q
How do hibernating animals survive their drop in body temperature
A
When mammals hibernate, their heartbeat slows, breathing rate drops, metabolism drops and body temperature drops. This can last between 3 and 7 days at a time
18
Q
Briefly explain how cells of plants living in subzero conditions survive the formation of ice crystals?
A
Because ice has formed, the concentration of water inside the living cells is higher than the concentration outside and so water moves out of cells. The movement of water out of cells increases the ion concentration inside the cells and so lowers their freezing point even further. The more concentrated cytosol works as an antifreeze
19
Q
Explain two features of plants that enables them to reduce heat uptake
A
Leaf shape- the larger ratio of edge length to surface area, the faster the leaf will be cooled
Leaf fall- leaf fall during the dry season decreases the surface area through which heat may be gained and water vapour lost
20
Q
Explain the dangers of evaporative cooling for a plant
A
During transpiration, excessive water loss in plants can cause death
21
Q
Where are the vasopressin and renin formed and what is the role of each in water balance
A
- Vasopressin is formed in the hypothalamus of the brain. If there is a drop in the blood, vasopressin gets released into the bloodstream via the posterior pituitary gland. It is transported to the kidney where it increases the amount of water that gets absorbed.
- Renin is found in the kidneys, when dehydration occurs. The function of renin is to restore normal blood pressure, thereby increasing filtration rates of water and salutes in the kidney tubules so that filtration proceeds in proper balance
22
Q
Explain how a variation in water balance causes a variation in blood pressure
A
As water content varies, blood pressure also varies. Increased water content raises blood pressure, decreased water content lowers blood pressure. The process of osmoregulation and blood pressure control interact
23
Q
Why is water loss from a plant inevitable?
A
When stomata are open, gases, including water vapour, are able to diffuse in or out of the leaf
24
List the regions and cells through which water passes as it moves from the soil into a plant, to the leaves at to the atmosphere?
Water enter where the root hairs grow, it moves across the cortex and endodermis before it reaches the xylem. From the xylem into the leaf, water moves from the xylem into surrounding mesophyll cells. The water vapour moves out of leaves into the stomata
25
What causes the stomatal pores to open?
When guard cells become filled with water (become turgid), it causes the stomata pores to open
26
Give two special structures that reduce water loss from a plant
The cuticle- which is the waterproof outer layer of the leaf, reduces water loss
The pores of the stomata can vary how open they are
28
Explain how atmospheric humidity influences water loss from a plant
Water vapour moves out of stomatal pores in a leaf much more quickly when the leaf is surrounded by dry air than when the leaf is surrounded by humid air
29
List the types of innate behaviours
COmmunication, Reproductive, Competitive
30
How would you classify a play dead behaviour
An communication behavior which is used to survive
31
Mother cats sometimes give their kittens live mice to play with. Why might such play be an important behavior for the kitten?
It is a learned behavior as it teaches the kitten association with the mice at a young age
32
What are the three kinds of learned behavior?
Conditioning, Habituation and Imprinting
33
How does a plant that is positively phototropic respond to light?
When the movement of a plant is towards the light is known as positive phototropism
34
How does a plant that is negatively geotropic respond to gravity?
Shoots show negative geotropism
35
Name two activities of plants that show a circadian rythm
Nastic Movement- Sensitive droop suddenly in response to touch
Solar Tracking - Leaves and flowers of plants move so they are parallel or perpendicular to the sun
36
How would you classify a plant that flowers after being exposed to light for 14 hours followed by 10 hours dark
it is a long day plant
37
Define the term habitat?
The location or place where an organism lives at any given time
38
List the three different kinds of habitat?
Terrestrial ( eg- deserts, grasslands etc)
Aquatic ( freshwater, marine,)
Microhabitat
39
Identify of using satellite habitats In monitoring habitats
Satellite technology is used to monitor vegetation in habitats that cover large areas
40
Identify three different animals whose movements in their habitats have been monitored for satellite tracking>
Tigers, Lions and Sharks
41
Whats a PAT Tag?
Pat tags are tags that are programmed to collect data every few minutes over given period of time
42
Two species of mammal living in the same habitat both eat insects. Based on this information alone, can it be concluded that the mammals have identical feeding niches?
Yes, as long as they are catching them in the same area they have identical feeding niches
43
List three different feeding niches in a freshwater lake habitat?
Vegetations at the bottom of the lake, fish, small plants and animals
44
Would it be reasonable to predict that several species living naturally in a natural community would have a high degree of niche overlap
No, as a high degree of niche overlap would lead to the elimination of one or two species
45
How would you be able to measure the relative humidity of the air
You would measure with a hygrometer
46
What instrument would you use to measure the salinity of the water
Conductivity Meter
47
Define Habitat
Part of an ecosystem in which an organism lives, feeds and reproduces
48
Define Range
Geographic area enclosing all the habitats where a given species lives; sometimes referred to as distribution
49
Define Niche
way of life of organisms in an ecosystem; roles of species in a community
50
Define Migration
Refers to the predictable movements of organisms over large distances, which may occur once in the lifetime of an organism (eg eels) or yearly (eg muttonbirds)
51
Define Population
Members of one species living in a specific habitat at a particular time
52
Define Environment
the surroundings or conditions in which a person, animal or plant lives or operates
53
What is the difference between freshwater vs marine habitats?
Freshwater includes lakes, rivers and ponds while Marine habitats includes Coral Reefs, Sandy Coastal Seafloors, coastal seas and open ocean waters
54
What is the relationship between the tolerance range and limiting factor of an organism?
Every organism has a tolerance range for environmental factors, such as temperature, oxygen concentration, light intensity and ultraviolet exposure. A tolerance range identifies the variation within which organisms can survive. Any condition that approaches or exceeds the limits of tolerance for an organism is said to be a limiting factor for that organism.
55
Define Adaptation
Features that appear to equip an organism for survival in a particular habitat
56
Structural Adaptations
Specialised body part of an organism that help it to survive in its natural habitat e.g skin, color, shape, body covering
57
Physiological Adaptations
Systems present in an organism that allow it to perform biochemical reactions eg. making venom, secreting slime, being able to keep a constant body temperature
58
Behavioral Adaptations
Special actions/ways a particular organism behaves to survive in its natural habitat
59
Distinguish between abiotic and biotic factors
- Biotic or living factors relate to other living organisms in the environment and include factors such as presence of predators, presence of parasites and competition between the members of one species
- Abiotic factors are nonliving factors relating to aspects of soil, water, light, temperature and topography, such as light intensity, slope of land, aspect of slope and rainfall
60
Distinguish between qualitative and quantitative
Qualitative refers to the description of the environment in imprecise terms, such as 'warm' 'shady'
Quantitative refers to a description of an environment using numerical values, such as '10 C' '75% cover'
61
Define Tropism
A directional growth response of a plant to an environmental stimulus
62
Where is auxin produced?
It is produced in the tip of a coleoptile and causes growth of cells in the coleoptile
63
Phototropism
Is the movement of plants in response to light
64
Thigmotropism
a plant response to contact with a solid object
65
Geotropism
Response of a shoot or root to gravity
66
Hydrotropism
the growth or turning of plant roots towards or away from moisture.
67
What is the difference between a positive and negative tropism?
When a plant grows towards a stimulus, the term positive tropism is used. Growing away from a stimulus is called negative tropism
68
What did Charles Darwins investigation about phototropism find?
Charles Darwin found that he could prevent bending towards the light by covering their growing tips. Darwin concluded that the tip of the seedling produced an 'influence' that passed from the tip to the region below the tip where the bending occurred
69
What causes a plant to bend towards the light?
If light is concentrated to one side of a coleoptile the auxin moves away from the light source to the darker side of the tip and becomes more concentrated. The increased concentration of auxin in these cells means they grow more quickly than the cells nearer the light. The uneven growth of cells results in bending of the coleoptile
70
Define Hormone
Chemicals produced in the endocrine glands, that are released into and transported via the bloodstream to other parts of the body where they act
71
Define Target Cell
A place where something happens, where a response occurs
72
What is the function of the hormonal/endocrine system?
The hormonal/endocrine system is the major controlling system in the body alongside the nervous system. It produces hormones, that helps maintains homeostasis
73
Function of the pancreas
The pancreas produces digestive enzymes that are secreted via a duct into the small intestine
74
Why are the endocrine glands called ductless glands?
They are called ductless glands as all hormones are secreted into the bloodstream
75
Define Negative feedback response
Is a control mechanism is homeostasis which moniters the state of a variable to see if it changes. If a change is detected a response is triggered to reverse the direction of the change
76
Name the 5 main plant hormones?
- Auxin
- Cytokinins
- Ethylene
- Absicic Acid
- Gibberellins
77
Functions of Auxin
- Promote plant elongation
- Regulate ripening of fruit and growth tips
- Inhibits the growth of lateral buds
- Promotes the growth of adventurous roots from stems
- Stimulates cells to divide
78
Function of Cytokinin
- Stimulate cell divison
79
Functions of gibberellins
- Promote cell division
| - Promote elongation
80
Function of Absicic Acid
- Acts as an inhibitor
- Promotes closure of stomata
- Stimulates dormancy in seeds and buds
81
Functions of Ethylene
- Significant in ripening fruits by stimulating the conversion of starch to sugars
- Stimulates colour change and softening of tissues of ripening fruit
82
Explain the mechanisms responsible for phototropism
The mechanism for regulation of bending by plants is described as a stimulus-response mechanism where the stimulus is the lightand the response is the bending/growth of the plant towards the light
83
Chemotropism
Response to chemicals in a plant
84
Distinguish positive feedback from negative feedback
Positive Feedback the enhancing or amplification of an effect by its own influence on the process which gives rise to it.
Negative Feedback is a regulatory mechanism that maintains a relatively steady value for body variables, such as blood glucose concentration, temperature and water concentration
85
Components of the nervous system
The nervous control system is composed of the brain, spinal cord and all the nerve cells connecting these to other parts of the body
86
Distinguish between the Central Nervous System and the Peripheral Nervous System
The brain and the spinal cord form the Central Nervous System (CNS). All other nerve cells, in whole or part, that lie outside the central nervous system form the peripheral nervous system (PNS)
87
Outline the components of a reflex arc
1. The receptor at the end of a sensory neuron reacts to a stimulus.
2. The sensory (afferent) neuron conducts nerve impulses along an afferent pathway towards the central nervous system (CNS).
3. The integration center consists of one or more synapses in the CNS.
4. A motor (efferent) neuron conducts a nerve impulse along an efferent pathway from the integration center to an effector.
5. An effector responds to the efferent impulses by contracting (if the effector is a muscle fiber) or secreting a product (if the effector is a gland).
88
Functions of a Neuron
The function of a neuron to transmit electrical nerve impulses and so carry information from one part of the body to another.
89
What are 3 types of neurons?
Sensory Neurons
Motor Neurons
Connecting Neurons
90
Sensory Neurons
Detect change in the external or internal environment and transmit information from receptors to the Central Nervous System
91
Motor Neurons
Carry information away from the Central Nervous System to muscle cells/glands and casue them to respond
92
Connecting Neurns
Inter-neurons located in the Central Nervous System linking sensory and motor neurons
93
What is a reflex action
A reflex action is brought about by the nervous system. It is an immediate short lived response to the stimulus eg - the withdrawal of a hand from a hot object
94
What is a reflex arc
A reflex arc is the pathway along which impulses travel and it is the basis of a reflex action. As few as 3 neurons may be involved.
95
Synapse
Is the junction between neurons
96
Define Positive Feedback
The response does not cancel out or reverse the stimulus and the stimulus response cycle occurs again
97
Define Action Potential
A short-term change in the electrical potential on the surface of a cell (e.g. a nerve cell or muscle cell) in response to stimulation, and then leads to the transmission of an electrical impulse (nerve impulse) that travels across the cell membrane.
98
Define Neurotransmitters
a chemical substance which is released at the end of a nerve fibre by the arrival of a nerve impulse and, by diffusing across the synapse or junction, effects the transfer of the impulse to another nerve fibre, a muscle fibre, or some other structure.
99
Distinguish between Hormonal and Nervous System
Hormonal - Slow reaction, long term, via blood stream, using chemical, maintains homeostasis, sends messages
Nervous - Fast reaction, Short Term, via neurons, using electrical impulses, uses chemicals, maintains homeostasis and sends messages
100
Define Homeothermic
Organisms body temperature is fairly constant regardless of external surroundings eg - mammals and birds
101
Define Poikilothermic
Animals body temperature varies with that of their environment eg - all animals other than birds and mammals
102
Define osmoregulators
Osmoregulation means the physiological processes that an organism uses to maintain water balance; that is, to compensate for water loss, avoid excess water gain, and maintain the proper osmotic concentration (osmolarity) of the body fluids
103
Define Osmoconformers
An osmoconformer is an organism whose body fluid solute concentration conforms to or is the same as the solute concentration of the external medium in which the organism lives.
104
Describe differences in osmoregulation for fishes in freshwater and marine environments
In freshwater fish the concentration gradient results in a loss of salts and an uptake of water. In marine fish concentration gradients results in a loss of water and an uptake of salts.
Freshwater fish must counter not drinking to maintain homeostasis while marine fish are able to drink sea water
105
Distinguish between innate and learned behaviours
Innate - Behaviours at are essentially the same in all members of the species
Learned - Behaviours that develop or change as a result of experience
106
Identify types of learned behaviour
trial and error
Conditioning - respond to stimulus that normally does not elicit response
Operant Conditioning - animal relates behaviour to reward or punishment
Habituation - cease to respond to stimuli
Imprinting - association with an object after exposure to it very early in life
Observational - learn from observing actions of others
107
Identify types of innate behaviours
Rhythmic behaviours - eg- daily eating, sleeping, migration
Communication behaviours
Social interactions - ( reproductive behaviour, competitive behaviours, dominance hierarchies, territoriality)
108
Link adaptations with the distribution of organisms within an environment
Some plants may refer or be better suited to specific niches such as mud on a pong floor, soft sediment or even having aquatic plants
109
Ways for plants to survive a fire
Radiation - radiates heat to other objects
Transpiration - heat is used for evaporation of water by stomata
Convection - air around cell becomes heated and as the heated air rises, heat is carried away from plants
Leaf shape - larger the edge length to surface area, the faster the leaf will be cooled
Orientation - expose less surface area to the sun
110
Identify Adaptations in Animals that limit heat loss
Fur
Feathers
Counter Current Heat Exchange
Shivering
Metabolism - Metabolic processes produce heat
Constriction of blood flow in skin
Piloerection - hairs standing on end, motor neurons convey messages from the hypothalamus to a muscle, causing muscles to contract and hair to become erect
111
Identify Adaptations in Animals that limit Heat Gain
Light Coloured fur
Distribution of fat
Dilation of arterioles - Motor neurons from hypothalamus send impulses through parasympathetic . This results in greater surface area across which heat exchange can take place, which means greater blood flow through skin so a greater loss of heat can occur
112
Explain how being nocturnal can aid thermoregulation
Being nocturnal is able to aid thermoregulation as the organism is no exposed to the sun and the temperatures are cooler
113
Examples of Inputs and Outputs relating to osmoregulation in terrestrial animals
Inputs - moisture in food
| Outputs - Urine , faeces, evaporation
114
Define and give an example of Circadian Rhythm
Circadian Rhythm refers to a pattern of activity following a 24 hr cycle.
Some plants have leaves tat follow a pattern with a daily rhythm. The leaves are horizontal during the day but fall into a 'sleeping' position at night
115
Define Territorial behavior
Animals select a territory and defend it against others for a number of reasons. eg- young, food, finding a mate
eg Magpie swooping humans for walking into their territory
116
Migration
Is the movement of large numbers of animals over long distances from one area to another area, and their subsequent return to their original home. Animals may migrate due to season or lack of food
117
Distinguish between Diurnal, Nocturnal, Crepuscular
Diurnal - active during the day, goes to sleep at night
Nocturnal - active at night, sleeps during the day
Crepuscular -active during dawn and dusk and sleeps the rest of the time
118
What are the aspects of communication?
```
Stimulus
Sender
Receiver to whom the signal is directed
Kind of Signal Sent
How the signal is sent
Behavior of receiver
Setting in which the communication occurs
```
119
Distinguish between internal fertilization and external fertilization?
Internal fertilization is the union of sperm and egg occurring inside the body of the female parent
External Fertilisation is the egg and the sperm fuse in the external environment, outside the body of either parent
120
Define and list Reproductive behaviors
```
Is the behavior patterns associated with courtship, mating and care for the young
eg - courtship - males attracting a mate
- Nest Site
- Commencement of breeding
- Time for young in nest
- Time young leaves nest
```
121
Distinguish between r and k selection
R- selection is the quick and many strategy and put little or no parental care into offspring and having higher mortality rates eg - reef fish, clams, oysters, mice
K - selection is the slower and fewer strategy - species mature slowly and parents put extensive parental care into their offspring eg - some birds, gorillas, elephants
122
Monogamy
One male mates with one female for one or more breeding seasons or for life eg - emperor penguins, eagle, parrot
123
Pologamy
Either one male or one female has multiple partners during a breeding season
124
Oviparity
Eggs are released by mother so that embryos develop outside the mothers body with nutrients for the embryo coming from the yolk eg- some sharks, all rays, bony fish, amphibians, all birds
125
Viviparity
Embryos develop within a mothers body and are born as miniature copies of the adult eg - some sharks, some snakes and all mammals (except for monotremes
126
Egg yolk viviparity
some sharks and snakes produce eggs that are retained in the mothers uterus and are nourished by egg yolk. After hatching in uterus, young are born as mature adults
127
Placental Viviparity
Mammals except for monotremes produce small eggs with little yolk enclosed within fluid filled sac that develops in uterus and exchange of nutrients and wastes via the placenta
128
Monotremes
Produce soft leathery eggs that guard until the young emerge. Parents provide food via mammary glands till the young are old enough to fend for themselves
129
Marsupials
Give birth to immature young which makes its way to the mothers pouch where it attaches itself to the nipple for the next 16-20 weeks
130
Placentals
retain the young in womb until it is fully formed at birth
