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Test 2 Flashcards

1
Q

What is genetics?

A

A branch of biology that deals with the transmission and variation of inherited characteristics, in particular chromosomes and DNA.

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2
Q

Why is DNA important?

A

DNA encodes the proteins responsible for our features. It also codes for enzymes (also proteins) responsible for all the reaction in our body.

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3
Q

What shapes us? Nurture or nature?

A

Both

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4
Q

What are chromatins?

A

DNA is organized along with proteins into a material called chromatin.

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5
Q

What are chromosomes?

A

-As a cell prepares to divide, the stringy, entangled chromatin coils up (condenses) becoming thick enough to be discerned as separate structures called chromosomes.
-A chromosomes is formed from a single DNA molecule that contains many genes.

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6
Q

When are chromosomes visible?

A

When the cell is in the process of dividing.

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7
Q

What is a gene?

A

-It is a segment of DNA that controls a hereditary characteristic. Genes are arranged in a fixed sequence along the chromosome.
-Segment of DNA located a specific on a specific chromosome that contains information for producing a particular protein (polypeptide)

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8
Q

How many chromosomes do humans have?

A

46 chromosomes (23 pairs)

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9
Q

What are autosomes?

A

All chromosomes except sex chromosomes

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10
Q

What do sex chromosomes do?

A

They determine someone’s gender

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11
Q

How many autosomes do we have?

A

22 pairs

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12
Q

What is a homologous pair?

A

In a homologous pair of chromosomes, each member carries genes for the same traits. One member of each pair was inherited from the mother, and the other from the father.

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13
Q

What are alleles?

A

An allele is an alternative form of gene located on a specific site of a specific chromosome. One allele is inherited from the mother, and the other from the father.

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14
Q

What is an homozygous pair of chromosomes?

A

When the pair of alleles on each homologous chromosome codes for the same version of the gene, the person is said to be homozygous for that trait.

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15
Q

What is an heterozygous pair of chromosomes?

A

When the pair of alleles on each homologous chromosome codes for the different version of the gene, the person is said to be heterozygous for that trait.

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16
Q

What is a dominant allele?

A

A dominant allele is observed as a trait in a heterozygous individual.

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17
Q

What is a recessive allele?

A

A recessive allele is only observed in a homozygous individual, it cannot be observed as a trait in a heterozygous.

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18
Q

What is a genotype?

A

A set of alleles

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19
Q

What is a phenotype?

A

Observable physical trait(s)

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20
Q

What can be used to predict the probability of the outcome of a given “cross” between individuals?

A

A Punnett square

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21
Q

What is a pedigree?

A

A chart showing the genetic connections between individuals

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22
Q

What is the function of a pedigree?

A

Allows to deduce one’s genotype for a dominant trait by knowing the ancestor’s expression for a particular trait.

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23
Q

What are the exceptions to the regular pattern (non mendelian inheritance)?

A
  1. Co-dominance
  2. Multiple alleles
  3. Incomplete dominance
  4. Sex linked inheritance
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24
Q

What is co-dominance?

A

It is when the phenotype of both allele is expressed.

ex: a fish is not red nor blue; it is red and blue

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25
What are multiple alleles?
When there is more than two possibilities of alleles. ex: blood types can either be O, A, or B (also co-dominant)
26
What is incomplete dominance?
The phenotype of individuals is in between the two alleles. ex: curly + straight hair = wavy hair
27
What is sex-linked inheritance?
It is observed when a gene coding for a trait is located on the X or Y chromosome. -If the gene is on the Y chromosome, only males can show the trait -If the gene is on the X chromosome, females have two versions of it (two alleles) and males only have one -Hence, males will show the trait if they have only one copy of the allele, even if it is a recessive (no possibility of dominant allele on homologous chromosome because it's a Y)
28
What are the organs of the nervous system?
Brain, spinal cord, peripheral nerves (including sensory neurons)
29
What are the functions of the nervous system?
-Communication between different parts of your body -Receive information from the receptors, analyze it and respond adequately -Homeostasis
30
What do the receptors do in homeostasis?
Pick up a stimulus or a deviation and sends the info through the sensory nerves.
31
What does the control center do?
Receives and integrates the information
32
What do the effectors do?
They receive a message from the control center to respond or correct the deviation
33
What parts of the body are the receptors?
Sensory organs and sensory cells
34
What parts of the body are the control center?
Brain and sometimes spinal cord
35
What parts of the body are the effectors?
Muscles and glands
36
What are the two main division of the nervous system?
Central nervous system and peripheral nervous system
37
What constitutes the central nervous system?
Brain and spinal cord
38
What is the function of the central nervous system?
Responsible for integration of information
39
What constitutes the peripheral nervous system?
Sensory nerves and motor nerves
40
What are the functions of the peripheral nervous system?
-Somatic nervous system (voluntary) -Automatic nervous system (involuntary) -Sympathetic nervous system -Parasympathetic nervous system
41
What is the function of the somatic nervous system?
Directs voluntary movements
42
What is the function of the autonomic nervous system?
Regulates involuntarily bodily activities, such as heart rate and breathing rate
43
What are the two subsections of the autonomic nervous system?
-Parasympathetic nervous system -Sympathetic nervous system
44
What is the function of the parasympathetic nervous system?
Governs bodily activities during restful conditions. Provides everything needed for normal functioning.
45
What is the function of the sympathetic nervous system?
Prepares body for stressful or emergency situations. Provides everything needed for the "fight or flight" response
46
What protects the central nervous system?
-Skull -Meninges -Cerebrospinal fluid -Vertebrae
47
What are the skull and vertebrae?
The bones of the skull and vertebral column are hard cases that protect the brain and the spinal cord.
48
What are the meninges?
The meninges are three membranes that protect the brain and spinal cord.
49
What is the cerebrospinal fluid?
CSF cushions the brain and spinal cord.
50
The spinal cord branches off to form what?
The spinal cord branches off to form spinal nerves (peripheral nervous system)
51
What is the blood-brain barrier?
It is made of cells that protect the central nervous system by permitting certain substances to diffuse from the blood to the brain while inhibiting others from entering.
52
What is the default of the blood-brain barrier?
It inhibits potentially life-saving, infection-fighting, or tumor-suppressing drugs that are not lipid soluble from reaching brain tissue. This makes the brain tissues fragile to infections.
53
What are the three parts of the brainstem?
Midbrain, pons, medulla oblongata
54
What are the regions of the brain?
Brainstem, cerebellum, cerebrum, corpus callosum, thalamus, hypothalamus
55
What is the function of the cerebellum?
-It coordinates sensory-motor voluntary movement. -It stores memory of learned motor patterns
56
What are the functions of the cerebrum?
-Contains sensory areas for skin senses, vision, hearing, olfaction. -Motor areas for voluntary control of movement -Association areas for interpreting sensations, language, thinking, decision making, self-awareness, creativity, and storage of memories
57
What are the functions of the corpus callosum?
It allows left and right cerebral hemispheres to communicate with one another.
58
What are the functions of the thalamus?
-It processes all sensory information (except olfaction) -Relays information to appropriate higher brain centers
59
What are the functions of the hypothalamus?
-Controls heart rate, blood pressure, breathing rate, body temperature, food intake -Is a center for emotions -Serves as "master biological clock"
60
What are the lobes of the cerebrum?
-Frontal lobe -Parietal lobe -Occipital lobe -Temporal lobe
61
What is the function of the frontal lobe?
High function associations
62
What is the function of the parietal lobe?
Sensory inputs, orientation, language processing, etc.
63
What is the function of the occipital lobe?
Visual inputs
64
What is the function of the temporal lobe?
Auditory inputs
65
What is the function of the sensory part of the peripheral nervous system?
It is responsible for receiving external or internal information and convey this info to the central nervous system.
66
What is the function of the motor part of the peripheral nervous system?
It is responsible for sending messages from the brain to the effectors (muscles and glands).
67
What is a tissue?
A group of specialized cells performing a specific function.
68
What is the function of the nervous tissue?
The function of the nervous tissue is to allow communication between parts of the body.
69
What are the two types of cells of the nervous tissue?
-Neurons -Neuroglial cells
70
What is the function of neurons?
Transmit impulses
71
What is the function of neuroglial cells?
They assist the propagation of the nerve impulse and provide nutrients to the neuron (support) (only in CNS)
72
What is a neuron?
The neuron is the functional unit of the nervous system.
73
How many neurons do humans have in their brain?
100 billion neurons and about 10-50X more glial cells.
74
What property do neurons have?
Neurons have the property of electrical excitability - the ability to respond to a stimulus and convert it to an action potential (impulse).
75
What are dendrites?
Highly branched input structures emerging from the cell body. It is the part of the neuron which receives the information.
76
What is the cell body?
It contains the nucleus, cytoplasm, and typical organelles.
77
What is the Axon Hillock?
It is the junction between the cell body and axon. Where the action potential (nerve impulse) originates.
78
What is the axon?
It conducts the information away from the cell body toward the axon terminal, and then to another neuron or an effector.
79
What are axon terminals?
It is at the end of the axon and contains the neurotransmitters to communicate with the next neuron.
80
What is the myelin sheath?
Glial cells located around the axon that allow faster conduction of the nerve impulse.
81
What are the three type of neurons?
-Sensory neurons -Interneurons -Motor neurons
82
What is a sensory neuron?
Neurons that take nerve impulses from sensory receptor (sense organs) to CNS.
83
What are interneurons?
They are located between sensory and motor neurons within the CNS. They integrate and interpret sensory signals. They account for more than 99% of the body's neurons.
84
What are motor neurons?
They carry information away from the CNS to an effector (muscles, glands, etc.)
85
What are the steps in a reflex arc?
1. A stimulus initiates a pain sensation. 2. Sensory messages are carried to the spinal cord by a sensory neuron. 3. Interneurons in the spinal cord integrate information from sensory neurons and stimulate the appropriate motor neurons. 4. Motor neurons stimulate the appropriate muscles. 5. Leg muscles contract causing them to lift the foot off the grass.
86
What is a synapse?
A synapse is the junction between two neurons or between a neuron and an effector such as a muscle or gland.
87
What are the two types of synapses?
1. Electrical 2. Chemical
88
How does an electrical synapse work?
The ionic current spreads to the next cell through physical junctions between the cells.
89
What are the advantages of electrical synapse?
1. Faster transmission 2. Synchronizing groups of neurons
90
How does a chemical synapse work?
Uses chemical molecule called a neurotransmitter, released by the presynaptic neuron (before the synapse, the first neuron in the synapse)
91
What is a postsynaptic neuron?
It is the second neuron in the synapse.
92
What are the steps involved in chemical synapse?
1. When the action potential arrives at the axonal end of a presynaptic axon. 2. Depolorization opens calcium channels (which are present at the synaptic knobs). Calcium flows into the cell. 3. Increased calcium concentration (inside knob) triggers the release of synaptic vesicles, which release neurotransmitter molecules (NTM) into the synaptic cleft. 4. NTM diffuses across cleft to NTM receptors on the postsynaptic neuron. Binding of NTM, opens ion channels on the postsynaptic neuron (eg. Na+) 5. Opening of channels in the postsynaptic neuron (change the voltage across membrane). Change in membrane potential of the postsynaptic neuron. -It can become more positive (depolarization) -It can become more negative (hyperpolorization)
93
What are the two main reaction to neurotransmitters?
-Inside of the cell becomes more positive (depolarization) -Inside of the cell becomes more negative (hyperpolorization)
94
Explain the first possible reaction to neurotransmitters
Positive ions enter the postsynaptic cell, making the inside of the cell more positive, increasing the likelihood that an action potential will begin. Excitatory postsynaptic potential
95
Explain the second possible reaction to neurotransmitters
Ions enter or exit the postsynaptic cell, making the inside of the cell more negative, reducing the likelihood that an action potential will begin. Inhibitory postsynaptic potential
96
What are the two types of chemical synapses?
-Excitatory synapse: binding of NTM opens channels that makes the postsynaptic neuron more positive (increases chances of action potential) -Inhibitory synapse: binding of NTM opens channels that make the postsynaptic neuron more negative (reduces the chances of generating an action potential)
97
How many synapse can a neuron have with other neurons?
As many as 10,000 synapses
98
What is summation?
Combined effects of excitatory and inhibitory effects in the postsynaptic cell at any given moment to determine whether an action potential is generated.
99
What is spatial summation?
Spatial summation occurs when several excitatory postsynaptic potentials arrive at the axon hillock simultaneously.

Biology (4 decks)

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