Test 1 Flashcards
1
Q
What is biology?
A
It is the science of life (living organisms and their environment).
2
Q
What is the organisation of life?
A
- Atom
- Molecules
- Organelles
- Cell
- Tissue
- Organ
- Organ system
- Individual
- Population
- Community
- Ecosystem
- Biosphere
3
Q
What are emergent properties?
A
Emergent properties necessarily come from the interactions of the parts of the larger system.
4
Q
What do all organisms have in common?
A
- Contains the same macromolecules
- Composed of at least one cell
- Grows and reproduces
- Uses energy
- Responds to their environment
- Maintains homeostasis
- Evolves and adapts
5
Q
What are the macromolecules that all organisms have?
A
- Nucleic acids
- Proteins
- Carbohydrates
- Lipids
6
Q
What is the definition of metabolism?
A
It is the sum of all chemical activity (growth, repair, muscles, etc.)
7
Q
Where do we take our chemical energy from?
A
Food
8
Q
What is homeostasis?
A
It is the ability to keep a relatively stable state of equilibrium.
9
Q
What is one important mechanism of homeostasis?
A
Negative feedback
10
Q
What is negative feedback?
A
Primary mechanism of homeostasis, whereby a change in a variable triggers a response that counteracts the initial change.
11
Q
What are the three physiological components necessary to keep homeostasis?
A
- Receptors
- Control Center
- Effectors
12
Q
What pathway is used to go from receptors to control center?
A
Afferent pathway
13
Q
What pathway is used to go from control center to effector?
A
Efferent pathway
14
Q
What system has the role of receptor in the human body?
A
The nervous system
15
Q
What system has the role of the control center in the human body?
A
Nervous system
16
Q
What systems have the role of effectors in the human body?
A
Muscular system and endocrine system
17
Q
Name all organ systems
A
- Integumentary system
- Skeletal system
- Muscular system
- Neurons and nervous system
- Sensory system
- Endocrine system
- Cardiovascular system
- Respiratory system
- Digestive system
- Urinary system
- Reproductive system
18
Q
What system is the pancreas part of?
A
Endocrine
19
Q
What system is the heart part of?
A
Cardiovascular
20
Q
What system are the lungs part of?
A
Respiratory
21
Q
What system is the stomach part of?
A
Digestive
22
Q
What system are the kidneys part of?
A
Urinary
23
Q
What system are the testes and ovaries part of?
A
Reproductive
24
Q
What system are the eyes part of?
A
Sensory
25
What system is the brain part of?
Nervous system
26
What system are the muscles part of?
Muscular
27
What system are the bones part of?
Skeletal
28
What system is the skin part of?
Integumentary
29
What is the cell theory?
1. Cells are the smallest unit of life
2. All cells come from cells
3. All living organisms are made of at least one cell
30
What are the two types of cells?
Eukaryotic and prokaryotic
31
What type of cell are bacteria?
Prokaryotic
32
What are prokaryotes?
Simple organisms without a nucleus such as a bacteria
33
What are eukaryotes?
More complex organisms with a nucleus
34
What are the differences between eukaryotic and prokaryotic cells?
-Prokaryotic cells are 10 times smaller
-Prokaryotic cells contain less organelles; they only have ribosomes
-Prokaryotic cells do not have a nucleus to contain their genetic material (DNA)
35
Which type of cell specializes and adopts different shapes based on their function?
Eukaryotic
36
What do many cells working together form?
Tissue
37
What are the functions of a cell membrane?
1. Maintain structural integrity of the cell
2. Regulates movement of substances into and out of the cell
3. Provides recognition between cells
4. Enables communication between cells
5. Sticks cells together to form tissues and organs
38
The plasma membrane is said to be...
Selctively permeable
39
Why does the membrane need to control what comes in and out of the cell?
Because molecules and ions concentrations must be kept constant inside the cell
40
What does cell recognition serve for?
It protects cells from invaders like viruses
41
How does the cell membrane allow cell attachment?
Cell adhesion molecules are embedded in the cell membrane and allow cell to attach
42
What are the main composants of the plasma membrane?
-Proteins
-Phospholipids
-Carbohydrates
-Cholesterol molecules
43
What are phospholipids?
They are fluids
44
What do phospholipids of the membrane allow?
They allow to keep the structure of the cell
45
What do proteins in the membrane allow?
They allow cell-recognition, cell-attachment and cell communication
46
What characterizes the head of the phospholipids?
Water-soluble/hydrophilic
47
What characterizes the tail of the phospholipids?
Fat soluble/hydrophobic
48
Is the outside of the membrane hydrophobic or hydrophilic?
Hydrophilic
49
Does the membrane let hydrophilic or hydrophobic molecules in?
Hydrophobic
50
What can cross the membrane?
1. Small molecules
2. Hydrophobic molecules
51
What cannot cross the membrane?
1. Large hydrophilic molecules
2. Charged particles
3. Cells (bacteria) or viruses
52
What are the different mechanisms to move across the cell membrane?
-Simple diffusion (passive)
-Facilitated diffusion (passive)
-Osmosis (passive)
-With a carrier protein (active)
-Exocytosis (active)
-Endocytosis (active)
53
What are the two types of transport across cell membranes?
Active and passive transport
54
What is the definition of passive transport?
Movement of molecules that does not require energy. Generally, with their concentration gradient (high to low).
55
What is the definition of simple diffusion?
Movement of molecules from region of high concentration to a region of lower concentration.
56
What is the definition of facilitated diffusion?
Movement of substances across the cell membrane through a membrane protein.
57
When are carrier proteins involved in passive transport?
When a non lipid soluble molecule is transported from a high concentration area to a low concentration area.
58
What is the definition of osmosis?
Movement of water from a region of low concentration to a region of high concentration.
59
What does high concentration means?
Substance in which there is many dissolved particles ( high solute).
60
What does hypertonic mean?
High concentration solution
61
What does isotonic mean?
Equally concentrated solution
62
What does hypotonic mean?
Low concentration solution
63
What is the definition of active transport?
Movement of substances that requires energy (generally against their concentration gradient)
64
When are carrier proteins involved in active transport?
When a molecule crosses against its concentration gradient
65
When does endocytosis occur?
When a region of the plasma membrane engulfs large molecules (bulk transport)
66
When does exocytosis occur?
Occurs when large molecules leave the cell through the fusion of a vesicle with the membrane (bulk transport)
67
What are the different reasons why a cell would want to divide?
1.Growth and development
2. Asexual reproduction
3. Tissue repair/renewal
68
What does chromatin mean?
Genetic material in the nucleus when the cell is not dividing.
69
What does chromosomes mean?
Genetic material packed (DNA is coiled with proteins)
70
What does sister chromatids mean?
Sister chromatids are the exact copies of a chromosome.
71
What does genome mean?
Entire genetic composition
72
What do genes code for?
Proteins
73
What is a karyotype?
Genetic material is photographed and arranged by size.
74
What are autosomes?
They are chromosomes that do not include sex chromosomes. You get one from your dad and one from your mom so you have 22 pairs (44).
75
What are sex chromosomes?
These chromosomes determine the sex of a person. We get one from our dad and one from our mom. So, we have one pair (2).
76
What are the sex chromosomes for a male?
XY
77
What are the sex chromosomes for a female?
XX
78
What sex chromosome does the mother pass?
X
79
What is the phase before mitosis begins?
Interphase
80
What are the stages of interphase?
1. Growth 1
2. DNA synthesis
3. Growth 2
81
What happens during growth 2 (before mitosis)?
1. Growth and final preparations for cell division
2. Chromosomes consist of two chromatids
82
What happens during synthesis?
DNA replication during interphase forms two sister chromatids, which are banded together to form a chromosome.
83
What happens during cytokinesis?
The parent cell divides, forming two daughter cells. Each daughter cell has two copies of each chromosome (homologous pairs).
84
What are the stages of mitosis? Name them in order.
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase
85
What happens during prophase?
1. Chromatin condenses (becomes visible) into chromosomes
2. Nuclear membrane breaks down
3. Rails (mitotic spindles) are produced by the centrioles, which move away on each side of the cell
86
What happens during metaphase?
Sister chromatids align in the middle. These sister chromatids are exact copy of each other.
87
What happens during anaphase?
Sister chromatids of each chromosome separate, following the rails (mitotic spindles)
88
What happens during telophase?
Nuclear envelope forms around each group of chromosomes
89
What happens during cytokinesis?
Microfilaments start to pinch the cell until it separates the two cells
90
What is interphase and what happens during interphase?
1. Interphase is the period in between cell division
2. DNA is in form of chromatin; long thin threads
3. DNA is copied during the S phase
4. Growth occurs during G1 and G2 phases
91
What is cancer?
It is uncontrolled cell division
92
What are check points?
The cell needs to go through a control area at various stages of its cell cycle. If anything is wrong, the cell cycle will stop and the cell will not divide.
93
Where are the checkpoints?
1. G1 checkpoint
2. G2 checkpoint (G2-metaphase)
3. M checkpoint (metaphase-anaphase)
94
What is apoptosis?
Programmed cell death
95
What happens during apoptosis?
The cell develops bulges (blebs)
96
How are tumors created?
They are created when the checkpoints are not working and the cell divides without control.
97
What are the differences between malignant tumours and carcinoma situ tumors?
-Carcinoma situ tumors remain at their site of origin.
-Malignant tumors attract a blood supply (by releasing growth factors), gain the ability to leave the other cells and then spread to distant sites (metastasize)
98
What are the functions of the nucleus?
-The nucleus contains and protects the DNA during interphase.
-It is the site of ribosome production
-Molecules can move in and out of the nucleus through the pore of the membrane
99
What are the functions of the Rough Endoplasmic Reticulum?
-Responsible for the fabrications of proteins to be used outside the cell (exported) or that will end up in the membrane.
-The proteins produced are sent away via little pouches called vesicles
100
What are the functions of attached ribosomes?
-Production of proteins that will be used outside the cell or the proteins of the membrane
101
What are ribosomes made of?
Proteins and RNA
102
What are the functions of the smooth endoplasmic reticulum?
-Responsible for making lipids
-Detoxification of drugs by making the drugs inactive
103
What are the functions of the Golgi complex?
-Receives the proteins from the rER through the vesicles
-Adds some markers to the proteins before they are sent to the rest of the body through the blood
-The markers label and direct them to the correct areas in the body
104
What are the functions of mitochondrion?
-Uses glucose and oxygen to produce energy (ATP) for the body
-Also produces a toxic gas called CO2
105
What are the functions of the lysosomes?
-The enzymes of the lysosomes will eat any of the used organelles or pathogens that are present in the cell to make them inactive
-Then, the small parts will be reused for other purposes
-Considered to be the recycling centre of the cell
106
What are the functions of free ribosomes?
Free ribosomes make proteins, but only the ones that are used inside the cell.
107
What does sexual reproduction involve?
-It involves the fusion of two cells and the genetic information of each to create an organism
108
What is the function of sex?
Produces genetically unique offspring that share traits with the parents
109
What does sexual reproduction require?
Requires a meiotic cell division in the lifecycle of the organism to produce gametes.
110
What are gametes?
Gametes are our sex cells (sperm and egg cells)
111
What is the goal of meiotic cell division?
The goal in meiotic cell division is to produce genetically unique cells with half the number of chromosomes
112
Are cells produced by meiosis haploid or diploid?
Haploid
113
What is the function of meiosis?
Production of genetically unique cells with half of the number of chromosomes for sexual production
114
How many divisions of nucleus and divisions of the cytoplasm occur during meiosis?
Two division of nucleus and two divisions of cytoplasm
115
What are the stages of a meiotic cell division?
1. Interphase
2. Meiosis 1
3. Cytokinesis 1
4. Meiosis 2
5. Cytokinesis 2
116
Why is there only one interphase?
Because each chromosome is only replicated once.
117
How many chromatids are there at the beginning of Meiosis 1?
92
118
What happens during interphase of meiosis?
Uncondensed chromosomes are replicated in the parent cell.
119
What happens during early prophase 1?
Replicated homologous chromosomes pair forming tetrads (4 chromatids).
120
What happens during late prophase 1?
Crossing over occurs between chromatids of the homologous chromosomes. Sister chromatids of a replicated chromosome are no longer identical.
121
What happens during metaphase 1?
Tetrads line up along the middle of the cell. Orientation is random.
122
What happens during anaphase 1 and telophase 1?
Homologous chromosomes in the tetrad are separated and pulled to opposite poles. 2 nuclei for form and cytokinesis divides the cytoplasm (not shown).
123
What happens during anaphase 2?
Sister chromatids separate
124
What are the three aspects of sexual reproduction that create variation in the genetic makeup of offspring?
-Distribution of homologous chromosomes (variation in gametes)
-Crossing over (variation in gametes)
-Fertilization (variation in zygote)
125
What is a gene?
Segment of DNA located in a specific site on a specific chromosome that contains information for producing a particular protein.
126
What is an allele?
An allele is an alternative form of a gene located on a specific chromosome. One allele is inherited from the mother, and the other from the father.
127
How does the distribution of homologues produce genetic variation?
-Each time a cell divides using meiosis, homologous pairs line up in one of millions of possible ways.
-Each meiosis packages unique combinations of maternal and paternal chromosomes into gametes leading to unique combinations of alleles for all genes in the genome.
-There are millions of ways that maternal and paternal chromosomes can be stuffed into gametes creating millions of unique possible combinations for alleles.
128
How does crossing over produce genetic variation?
-Portions of chromosomes are exchanged between homologues making recombinant chromosomes.
-Alleles for genes on the same chromosome can be unlinked and shuffled into unique combinations in these recombinant chromosomes.
-Crossing over helps create even more unique combinations of alleles in gametes produced by meiosis.
129
How does fertilization produce genetic variation?
-Individuals are likely to contain different alleles for genes and produce different gametes.
-Two unique gametes combine randomly to form a unique zygote that develops into an offspring.
-An astranomical number of genetically distinct offspring can result from any one human mating.
130
What happens during spermatogenesis?
Spermatogenesis produces four sperm cells that are specialized to transport the male's genetic information to the egg.
131
What happens during oogenesis?
Oogenesis produces one egg that is packed with nutrients to nourish the early embryo. The polar bodies are not used as gametes.
132
What are the two types of mistakes in cell division?
Mutation and aneuploidy
133
What is mutation?
It is a change to chromosome structure
134
What is aneuploidy?
It is a change to chromosome number.
135
What can mutations alter?
1.The structure and function of the protein made from the gene
2. Regulation of the gene (turning on or turning off the gene)
136
What kind of mutations result from mitosis?
Somatic cell mutation
137
What kind of mutations results from meiosis?
Germ-line mutation
138
What causes aneuploidy?
Nondisjunction during cell division. That is, chromosomes fail to be separated correctly and daughter cells have an abnormal chromosome numbers.
139
Will a zygote formed by one aneuploid gamete and one normal gamete be normal?
No, will be aneuploid.
140
Does aneuploidy only involve sex chromosomes?
No, it can also involve autosomes.
140
Does aneuploidy only involve sex chromosomes?
No, it can also involve autosomes.
141
How many cells will be aneuploid if there is a disjunction during the first meiosis?
Four cells will be aneuploid (two cells will be missing a chromosome and the other two cells will have once extra chromosome)
142
How many cells will be aneuploid if there is a disjunction during the second meiosis?
Two cells will be aneuploid.
143
Which is the gravest, a disjunction during the first meiosis or a disjunction during the second meiosis?
During the first meiosis.
144
Which is the gravest, a disjunction during the first meiosis or a disjunction during the second meiosis?
During the first meiosis.
145
What happens to most aneuploid zygotes?
They do not develop into viable offspring. Aneuploidies account for most spontaneous abortions.
146
What are the two types of aneuploidies in offspring?
1. Monosomy
2. Trisomy
147
What is monosomy?
It is the condition in which somatic cells contain only one of a chromosome pair.
148
What is trisomy?
It is a condition in which somatic cells contain three copies of one chromosome.
149
What is the other name given to trisomy 21?
Down syndrome
150
Does trisomy involve sex chromosomes or autosomes?
Autosomes
151
What is the other name for monosomy X?
Turner's syndrome
152
What is Turner's Syndrome?
Occurs when an infant is born with one X chromosome. The infant is therefore a female suffering from Turner's Syndrome.
153
Apart from Turner's Syndrome, are there other monosomy observed in humans?
No
