biology Flashcards
1
Q
what are the four functions of the circulatory system?
A
- transports O2 and nutrients
- transports heat throughout the body
- distributes energy thought the body
- defends against pathogens
2
Q
what does a heartbeat consist of?
A
a complete contraction (systole) and a complete relaxation (diastole)
3
Q
which direction do arteries carry blood in?
A
away from the heart
4
Q
what is the largest artery in the body?
A
the aorta
5
Q
what do arteries branch off into?
A
arterioles
6
Q
what do coronary arteries supply blood to?
A
the heart
7
Q
what kind of vessels are arteries?
A
they are thick and muscular and can withstand high pressure
8
Q
what happens if coronary arteries are blocked?
A
it can cause a heart attack
9
Q
what happens if an artery in the brain is blocked?
A
it can cause a stroke
10
Q
which direction do veins carry blood in?
A
towards the heart
11
Q
what kind of vessels are veins?
A
smaller and thinner than arteries, low pressure
12
Q
what type of blood vessels contain valves?
A
veins
13
Q
why do veins contain valves?
A
to prevent back flow because blood is usually travelling against gravity
14
Q
what does blood movement in veins depend on?
A
the contractions of surrounding muscles
15
Q
what is the largest vein called?
A
the vena cava (superior and inferior)
16
Q
what are smaller branches of veins called?
A
venules
17
Q
what happens when valves in the veins are faulty?
A
varicose veins
18
Q
what are capillaries?
A
tiny blood vessels that connect to the smallest branches of arterioles and venules
19
Q
how thick are capillaries?
A
one cell thick
20
Q
what do capillaries do?
A
bring nutrients and oxygen to tissues and remove waste products
21
Q
what makes the lub-dub sound of a heartbeat?
A
the valves opening and closing
22
Q
what does a heartbeat consist of?
A
a complete contraction (systole) and a complete relaxation (diastole)
23
Q
what does a contraction consist of?
A
the atria contracting followed by the ventricles
24
Q
about how much blood do we have in our bodies?
A
5L
25
how much of the blood does plasma make up?
about 55%
26
what is plasma made of?
- water
- dissolved CO2
- waste
- hormones
- proteins
27
what is the lifespan of a RBC?
about 120 days
28
where are RBCs, WBCs and platelets produced?
bone marrow
29
why is the shape of RBCs beneficial?
provides a large surface area for gas exchange and allows them to travel easily through the blood vessels
30
what is the benefit of RBCs not having a nucleus?
provides more room for hemoglobin on the surface of the cell
31
what iron binds to oxygen to transport it through the body?
hemoglobin
32
what is it called when hemoglobin bonds to oxygen?
oxyhemoglobin
33
what is sickle cell anemia?
a disorder that results in abnormally shaped RBCs which deliver less oxygen to the body
34
what is the lifespan of a white blood cell?
13-20 days
35
what are platelets responsible for?
clotting
36
what is the clotting process?
1. dissolved fibrinogen comes in contact with a rough surface
2. fibrinogen converts to active form: fibrin
3. fibrin forms a mesh that traps RBCs to form a clot
37
is fibrinogen active or inactive?
inactive
38
what is the active form of fibrinogen?
fibrin
39
what is "bad" cholesterol?
LDL (from land animals) - it contributes to fatty buildups in arteries
40
what is "good" cholesterol?
HDL (from marine animals) - it carries LDL out of the body
41
what is atherosclerosis?
the build up of cholesterol inside the arteries (aka. coronary heart disease)
42
what is angina?
a cramping pain behind the breastbone, stretching out to the neck and arms caused by a lack of oxygen to the heart. often a symptom of atherosclerosis
43
what is a pathogen?
disease causing agent
44
what does fungi live off of?
dead or decaying organisms
45
what are examples of fungi?
athletes foot, ring worm
46
what is bacteria?
single celled organisms, no nucleus, can reproduce themselves
47
what are viruses?
microorganisms, require a host cell to reproduce, contain genetic information
48
what type of pathogen responds to antibiotics?
bacteria
49
what type of pathogen responds to vaccinations?
viruses
50
what are examples of bacteria?
strep throat, meningitis
51
what are examples of viruses?
HIV, flu, herpes
52
what is the first line of defence?
barriers that prevent the pathogen from entering the body
53
what prevents most pathogens from entering the body?
skin
54
how does skin prevent pathogens from entering the body?
it produces sweat and acidic oil secretions
55
how does the nose prevent pathogens from entering the body?
nasal hairs and mucus secretions
56
how do the eyes defend against pathogens?
they produce an antiseptic liquid
57
how does the stomach defend against pathogens?
HCl
58
what is the second line of defence?
occurs when the pathogen has entered the body, inflammation and fever help to fight against pathogens
59
what is the third line of defence?
this is an immune response specific to the pathogen
60
what are antigens?
unique proteins on the surface of a pathogen that triggers the immune response
61
what are antibodies?
proteins molecules produces in WBCs that bind to specific antigens to disable the pathogen
62
what is the first WBC to respond to a pathogen?
macrophages
63
what do helper T-cells do?
they bind to the antigens and send out hormone signals to coordinate the response of other cells
64
what do killer T-cells do?
if the pathogen is a virus they release a protein to destroy infected cells
65
what to B-cells do?
they produce antibodies
66
what do memory B and T cells do?
they remain in the body after the infection and remember the antibody so the immune response can be quicker next time that pathogen enters the body
67
what do suppressor T-cells do?
they signal the immune response to stop
68
where do T-cells mature?
in the thymus gland
69
where do B-cells mature?
in the bone marrow
70
where do antigens appear?
on the surface of the pathogen, then on the surface of the macrophage after it engulfs the pathogen
71
what cells respond specifically to viruses?
killer T-cells
72
what cells signal the immune response to stop?
suppressor T-cells
73
how to WBCs send signals?
through hormones
74
how do antibodies help the immune response?
they bind to antigens which clumps pathogens so it's easier for macrophages to engulf them
75
at what point are you 7-10 days from recovery?
when the B-cells have produced antibodies
76
what is the order of the immune response?
1. WBCs identify a pathogen
2. macrophages engulf the pathogen and present the antigen on its surface
3. helper t-cells bind to and recognize the antigens, coordinating other cells to respond
4. killer t-cells destroy infected cells (virus)
5. b-cells produce antibodies
6. memory t and B cells are produced and remain in the body
7. suppressor t-cells signal the immune response to stop
77
what is an autoimmune disease?
this is when the body recognizes its own cells and tissues as foreign pathogens and launch an immune response
78
what are examples of autoimmune diseases?
multiple sclerosis, rheumatoid arthritis and lupus
79
what do vaccines do?
they prevent infection by having the immune system produce memory cells against a specific pathogen
80
what is a disease vector?
an organism that transmits pathogens to other organisms
81
what is an example of a disease vector?
mosquitos (malaria)
82
what WBC does the HIV virus attack?
helper T-cells
83
what can cause a vaccination to be ineffective?
if the virus has mutated
84
what is contained in a vaccination?
a weakened or altered form of the pathogen
85
why don't we use live pathogens in a vaccine?
so the full-blown form of the disease is not presented
86
what is rheumatoid arthritis?
the body's immune system attacking the bones and cartilage of the joints
87
why do we suppress the immune system of transplant patients?
so they don't reject the transplanted organ
88
what is a chromosome?
a strand of DNA that contains the instructions for making proteins
89
what is a gene?
a segment of DNA that carries instructions that result in the production of proteins
90
what is DNA?
the twisted ladder shaped molecule that contains genetic information
91
what is a centromere?
the region on a replicated chromosome that attaches the two identical copies during cell division
92
what is an autosomal cell?
a cell of the body not involved in sexual reproduction
93
what are homologous chromosomes?
a pair of identical chromosomes
94
what is a gamete?
a sex cell, such as a sperm and an egg, produced during meiosis with only one copy of each chromosome type
95
where is genetic information found?
in the nucleus of a cell
96
how many pairs of chromosomes does a human have?
23 pairs
97
how many chromosomes in total does a normal human have?
46
98
what is a karyotype?
an image of all chromosomes in a cell organized in pairs from largest to smallest
99
why are karyotypes useful?
they allow us to ID chromosomal errors and identify the sex of the offspring
100
how much of the mass of the body do proteins make up?
over 50%
101
what two processes are used in the reproduction of cells?
mitosis and meiosis
102
what is mitosis?
two identical daughter cells are produced to replace dead or damaged cells
103
in what type of cells does mitosis occur in?
autosomal
104
how do autosomal cells spend most of their time?
in the "rest" or "living" stage
105
how do chromosomes exists in the rest/living stage?
as chromatin
106
what is the first step of mitosis?
DNA replication
107
what happens during DNA replication?
1. chromatin condenses to form chromosomes composed of two chromosomes attached at the centromere
2. centrioles move to opposite sides of the cell and fibres extend from them to create the spindles
108
in what stage of mitosis does the nuclear membrane disappear?
stage 1 or DNA replication
109
how many stages are there in mitosis?
4
110
what is the second stage of mitosis?
the spindle fibres align the centromeres along the equator of the cell
111
what is the 3rd stage of mitosis?
1. the centromeres split and the chromosomes separate, moving to opposite sides of the cell
2. nuclear membranes form around each chromosome
112
what is the 4th stage of mitosis?what is the 2nd stage of meiosis?
1. the two cell membranes separate to form two distinct cells
2. the two new cells uncoil and enter the living stage
113
how many new cells are formed from mitosis?
2 identical cells
114
how many new cells are formed during meiosis?
4
115
how many chromosomes does each cell formed during mitosis have?
46 (diploid number)
116
how many chromosomes does each cell formed during meiosis have?
23 (haploid number)
117
what type of cells are formed during meiosis?
gametes
118
what is the first stage of meiosis?
DNA condense and replication
119
what is the 2nd stage of meiosis?
1. the chromosomes line up and twist together to transfer genetic information
2. the tetrad separates into two pairs of genetically unique chromosomes
120
what is the 3rd stage of meiosis?
cell division 1 -- the two pairs of chromosomes attach to spindle fibres and separate into two separate cells
121
what is the 4th stage of meiosis?
cell division 2 -- the chromosomes attach to spindle fibres and separate to form gametes
122
how many pairs of autosomal cells does the human body have?
22
123
how many pairs of sex cells does a human have?
1
124
what is a haploid cell?
a sex cell, it only has 23 total chromosomes
125
what sex chromosomes do males have?
one Y chromosome and one X chromosome
126
what sex chromosomes do females have?
two X chromosomes
127
what decides whether a baby is male or female?
the sperm, it can either have an X chromosome or a Y chromosome, but every egg has an X chromosome
128
in which type of cellular reproduction can chromosomal errors occur?
meiosis
129
what is an amniocentesis?
the process of removing some amniotic fluid to perform a karyotype and detect any chromosomal errors
130
what is non-disjunction?
this is a chromosomal error where the chromosomes have failed to separate during cell division
131
what does non-disjunction result in?
either having one extra chromosome (trisomy) or one less (monosomy)
132
what is a trisomy?
when there is an extra homologous chromosome, so there's 3 instead of 2
133
what is a monosomy?
when there is one less chromosome -- 45 instead of 46
134
what are the three types of mutations?
1. non-disjunction
2. point mutation
3. frameshift mutation
135
what is point mutation?
the substitution of one nucleotide base for another
ex. THE FAT CAT
THE BAT CAT
136
what are the two types of frameshift mutations?
1. addition
| 2. deletion
137
what is an addition?
a type of frameshift mutation, when a nucleotide base is replicated so there is one too many
ex. THE FAT CAT
THE FFA TCA T
138
what is a deletion?
when one nucleotide base is missing
ex. THE FAT CAT
THE ATC AT
139
who is considered the father of genetics?
gregor mendel
140
what did Gregor Mendel conduct experiments on?
pea plants
141
do genes apply to acquired traits?
no
142
what is an example of an acquired trait?
language
143
what is an example of an inherited trait?
eye color
144
what is an allele?
alternate forms of a gene, letters are used to represent them
ex. G = blue flowers
g = pink flowers
145
what is a dominant trait?
a gene that is stronger than a recessive gene, it only needs to be present in one parent in order to be shown in an offspring
146
what is a recessive trait?
the weaker allele, both parents must contain the recessive trait in order for the trait to be expressed in the offspring
147
what is a genotype?
a description using letters of the alleles present
ex. GG, Gg, gg
148
what is a phenotype?
a word description of the alleles
ex. blue eyes vs brown eyes
149
what does homozygous mean?
both alleles are the same
150
what does homozygous dominant mean?
the alleles are both the dominant trait
ex. BB
151
what does homozygous recessive mean?
the alleles are both the recessive trait
ex. bb
152
what does heterozygous mean?
the alleles are different
ex. Bb
153
what is the purpose of a punnet square?
to predict the possible genotype of offspring
154
what is co-dominance?
when two traits are not dominant over each other
155
what is sex-linked inheritance?
genes on sex chromosomes are responsible for sex-linked inheritance
156
what is the smallest unit in DNA called?
a nucleotide
157
what does a nucleotide consist of?
1. phosphate group
2. sugar molecule
3. nitrogenous base
158
what are the 4 nitrogenous bases?
1. adenine
2. cytosine
3. thymine
4. guanine
159
what does the double helix consist of?
a base pairs attaching together
160
what base does adenine bond to?
thymine
161
what base does guanine bond to?
cytosine
162
what base does thymine bond to?
adenine
163
what base does cytosine bond to?
guanine
164
what is the purpose of the double helix shape?
to make the shape of DNA thin and compact
165
what are proteins made up of?
chains of amino acids
166
what is a DNA triplet code?
a combination of any 3 bases that codes for a specific amino acid
167
what is a mutation?
a heritable change in the sequence of nitrogen bases along a DNA molecule
168
what is a genetic disease?
a disease caused by a mutation of one or more genes that can be inherited by future generations
169
what is a carrier?
an individual who has the allele for a disease but does not show the symptoms of it
170
what is a mutagen?
any agent that causes the likelihood of mutations to increase
171
what is a carcinogen?
any agent that causes the likelihood of cancer to increase, they are usually mutagens
172
what is genetic engineering?
the modification of genetic material through the actions of people
173
what is gene therapy?
the technique of using a vector such as a virus in the treatment and possible cure of diseases
174
what is a genetically modified organism?
an organism whose genetic material has been deliberately altered
175
what is a pedigree chart?
a genetic family tree
176
what represents females in a pedigree chart?
circles
177
what represents males in a pedigree chart?
squares
178
what represents affected individuals in a pedigree chart?
shaded symbol
179
what does a half-shaded symbol represent on a pedigree chart?
a carrier
180
how are antibiotic resistant genes passed?
some germs can give their resistance directly to other germs, but they occur naturally via mutations
181
what is a plasmid transfer?
this is when plasmids containing DNA are transferred meaning resistance genes are transferred with it
182
what is transformation?
this is the genetic alteration of a cell resulting from outside sources of genetic material
