Biology Final Flashcards
(184 cards)
1
Q
What are the four types of nitrogenous bases? How do they pair together?
A
Adenine—>Thymine.
Cytosine—> Guanine.
2
Q
What are the three structures that make up a DNA strand?
A
A nitrogenous base, deoxyribose sugar, and a phosphate group.
3
Q
What type of bond connects the nitrogenous bases together?
A
A hydrogen bond.
4
Q
What type of bond connects the deoxyribose sugar and the phosphate group together?
A
A covalent bond.
5
Q
What does 5’ connect to and what does 3’ connect to?
A
5’ connects the 5th carbon atom to the phosphate group, and the 3’ connects the 3rd carbon atom to the hydroxyl group.
6
Q
DNA molecules run ____ from one another.
A
antiparallel.
7
Q
How many chromosomes does each human have per cell?
A
46 chromosomes, 23 pairs.
8
Q
What connects the deoxyribose sugars together?
A
A phosphate group
9
Q
What happens to the DNA when it makes a copy of itself?
A
When the heavy DNA makes a copy of itself, it gets lighter.
10
Q
How does the leading strand copy?
A
The leading strand copies continuously towards the replication fork 5’ to 3’.
11
Q
How does the lagging parent template copy?
A
The lagging parent template copies 3’ to 5’ away from the replication fork.
12
Q
What is the first step of the DNA replication process?
A
The enzyme Helicase breaks H bonds between the Nitrogenous bases.
New strands are extended at the replication fork in both directions.
13
Q
What is the second step of the DNA replication process?
A
Primase works to identify the location of the gene where DNA polymerase is to replicate.
DNA Polymerase helps to attach the new nucleotides as they align with their base pair in the 5’ to 3’ direction.
14
Q
What is the third step of the DNA replication process?
A
Lagging strands (Okazaki fragments) extend in pieces away from the replication fork. The enzyme, DNA ligase attaches the fragments on the lagging strand into one piece.
15
Q
What are histones?
A
Protein molecules whose DNA is tightly coiled.
16
Q
What are the four enzymes used for DNA replication?
A
Primase, Ligase, DNA polymerase, and helicase.
17
Q
What is insertion? What is deletion? What is substitution?
A
When a base is added. When a base is deleted. When a base is changed or substituted.
18
Q
What type of mutation does insertion and deletion cause?
A
Deletion and Insertion may cause what’s called a frameshift mutation, meaning the reading ”frame” changes, thus changing the amino acid sequence from this point forward.
19
Q
What types of mutations does substitution cause?
A
Causes missense, nonsense, or a silent mutation.
20
Q
What is a silent mutation?
A
When only one codon is changed, it doesn’t affect the amino acid.
21
Q
What is a missense mutation?
A
When the codon(s) are changed, and the amino acid is affected.
22
Q
What is a nonsense mutation?
A
The codon changes the amino acid to a “stop” codon before the sequence is finished.
23
Q
What are the four bases of RNA?
A
Adenine-Uracil Cytosine-Guanine
24
Q
What is the definition of DNA versus RNA?
A
DNA has the genetic codes to control cell activities and create proteins.
RNA copies and translates genetic codes to build these proteins.
25
What is mRNA?
Stands for messager RNA. Copies the genetic code from DNA and carries it to the ribosomes to create proteins.
26
What is tRNA?
Stands for transfer RNA. Shaped like a T. Transfers specific amino acids by carrying them to the ribosome for protein synthesis.
27
What is rRNA?
Makes up ribosomes. Holds mRNA in place at the ribosome and catalyzes peptide bond formation.
28
What is transcription?
Making an mRNA copy of a gene on DNA in the nucleus.
29
What is translation?
Turning the copied mRNA into protein by decoding the mRNA at the ribosome.
30
What is a codon?
Three mRNA bases= 1 codon
| Each codon= 1 amino acid
31
What is an anti-codon?
3 nucleotides sequence complementary to the codon in an mRNA sequence.
Found at one end of a tRNA molecule.
32
List the four steps of cell division.
G1, Synthesis, G2, Mitosis
33
What steps are part of the interphase?
G1, Synthesis, and G2.
34
Explain what happens during each phase of the Cell Cycle.
In G1- The cell begins to grow
S phase- DNA is replicated
In G2- The cell grows even more and completely develops. Prepares for cell division.
Mitosis- The cell is divided into two daughter cells.
35
What are the different types of cell reproduction?
Sexually: Offspring is a combination of two parents.
Asexually: Offspring is identical to its single parent.
36
What parts of the Cell Cycle is interphase?
Interphase is not part of mitosis-it is the time between cell division. Interphase includes G1, S, and G2.
37
What are the three steps of prophase?
1. Mitosis begins. Chromatin is condensed into chromosomes.
2. Centrioles form spindle fibers and begin to move to opposite ends of the cell.
3. Nuclear membrane breaks down and disappears.
38
What are the two steps of Metaphase?
1. Chromosomes attach to the spindle fibers and line up at the equator (middle) of the cell, the metaphase plate.
2. Spindle assembly checkpoint: perfect chromosome separation can be guaranteed.
39
What are the two steps of anaphase?
1. The sister chromatids separate at the centromeres.
| 2. Each chromatid heads to opposite poles of the cell.
40
What are the three steps of telophase?
1. New nuclear membranes start to form around the DNA.
2. The chromosomes begin to decondense back to chromatin.
3. Cytoplasm begins to pinch in animal cells forming a cleavage furrow and a cell wall begins to form in plant cells- this is cytokinesis.
41
What do different checkpoints check for?
G1: The cell needs to have grown big enough.
G2: There can be no errors in DNA replication.
Middle of Mitosis (metaphase): DNA needs to be lined up evenly.
42
What is cancer?
Cancer is uncontrolled cell growth. They form in tumors of masses of abnormal cells.
43
What are the two steps of interphase?
1. Interphase is the stage of growth and preparation. 2. Chromosomes are copied (# doubles) and appear as threadlike unorganized coils, called chromatin, at first.
44
What is diploid?
Two complete sets of chromosomes, one from each parent.
45
What is a haploid?
One of each chromosome.
46
What is a gamete?
Sperm or egg cell, gametes are haploid.
47
What is fertilization?
The process of one male (sperm) gamete and one female (egg) gamete coming together.
48
What is a zygote?
A cell formed when two gametes come together.
49
How many divisions and DNA are in meiosis?
Two divisions, 1/2 DNA in each of the four cells, are four the cells are genetically different.
50
What is a somatic cell?
Any other cell other than reproductive cells.
51
What happens during prophase I?
1. Mitosis begins. Chromatin is condensed into chromosomes.
2. Centrioles form spindle fibers and begin to move to opposite ends of the cell.
3. Nuclear membrane breaks down and disappears.
4. Crossing over occurs.
52
What is crossing over?
Homologous Chromosomes exchange genetic information to create genetic diversity in gametes.
53
What are homologous chromosomes?
Homologous chromosomes are chromosome pairs (same number and length).
54
What happens during metaphase I?
1. Homologous Chromosomes attach themselves to spindle fibers.
2. Homologous Chromosomes align randomly at the equator as pairs.
3. Results in new genetic combinations/variations in gametes and therefore, offspring; greater genetic diversity.
55
What happens during anaphase I?
1. Homologous Chromosomes move apart to opposite poles once attached to spindle fibers (in metaphase).
56
What happens as an end result of telophase I?
1. The end result after cytokinesis is two cells with sister chromatids remaining to be separated.
57
Does DNA replicate again before meiosis II?
No, DNA doesn't replicate itself a second time.
58
What happens during prophase II?
1. Chromatin is recondensed into chromosomes.
2. Centrioles form spindle fibers and begin to move to opposite ends of the cell.
3. Nuclear membrane breaks down and disappears.
59
What happens during metaphase II?
1. Chromosomes attach to the spindle fibers.
| 2. Sister chromatids randomly line up along the metaphase plate like regular mitosis.
60
What happens during anaphase II?
1. During Anaphase II, centromeres break and each sister chromatid is pulled to opposite sides of the cell.
61
What happens during Telophase II?
1. The two cells split off, end result is 4 gamete cells that are genetically different from each other.
62
What are inherited mutations?
Inherited mutations are when mutations are passed from a parent onto an offspring. All of the offspring’s cells will carry the mutation.
63
What are new mutations in the germline?
New Mutations in Germline are when a mutation associated with a disease occurs during gamete production. The offspring can inherit the mutation from an unaffected parent.
64
What are somatic cell mutations in development?
The development of specific tissues and organs in the body can be affected by somatic cell mutations that occur early in life. Are inherited by a parent.
65
What are somatic cell mutations later in life?
Cancer can result from somatic cell mutations that occur later in life. Are inherited by a parent.
66
What are proto-oncogenes?
Proto-oncogenes normally function to accelerate cell growth/division.
67
What happens when proto-oncogenes are mutated?
If they’re mutated, they become oncogenes and accelerate cell division and growth way too quickly out of control.
68
What are tumor suppressor genes?
Tumor suppressor genes act to slow down cell division, repair DNA mistakes, and tell cells when to die.
69
What happens when tumor suppressor genes are mutated?
When mutated, they can cause cells to grow out of control which can lead to cancer.
70
What are DNA repair genes?
Normally functions to fix minor damages to DNA when the replication isn’t perfect.
71
What happens when DNA repair genes are mutated?
When tumor suppressor genes are mutated, this can lead to cancer because the replication damages aren’t fixed.
72
How do proto-oncogenes relate to a gas pedal?
Proto-oncogenes are similar to a gas pedal, helping cells grow and divide at a faster rate. When this gas pedal breaks, this causes the cells to divide uncontrollably.
73
How do tumor suppressor genes relate to a brake pedal?
Tumor Suppressor Genes are similar to a brake pedal. Keeps cells from dividing too quickly, just as a brake keeps a car from going too fast.
74
What is nondisjunction?
Failure of chromosomes to separate during anaphase in meiosis. This results in gametes having too many/few chromosomes.
75
When does nondisjunction occur?
Failure to separate can happen in homologous chromosomes during anaphase I or sister chromatids during anaphase II.
76
What happens when gametes that have nondisjunction are used during reproduction?
If these gametes are used during fertilization, this can lead to genetic disorders when the child develops and is born.
77
What is monosomy?
This refers to when a homologous chromosome lacks its partner in the genome. Presence of a single chromosome in the homologous pair. Represented as 2n-1.
78
What is trisomy?
When there is an additional copy of a chromosome present in the genome. Represented as 2n+`1.
79
What is down syndrome?
Down syndrome is when a patient has an extra 21st chromosome. Many facial characteristics, and can have cognitive disabilities.
80
What is Edward's syndrome?
Edwards's syndrome is when a patient has an extra 18th chromosome. Some characteristics are malformed ears and organs, cognitive disabilities, and there is a low survival rate after 6 months.
81
What is Klinefelter's syndrome?
Klinefelter's syndrome is when a patient has one or more extra X chromosomes; male. Some characteristics are small testes, female-like breasts, female-like voice, and developmental disabilities.
82
What is Patau's syndrome?
Patau's syndrome is when there is an extra 13th chromosome. Some characteristics are deafness, cleft lip/palate, and cognitive disabilities. A low survival rate after 3 months.
83
What is Turner's syndrome?
Turner's syndrome is when one of the sex chromosomes is missing. Is still female, some characteristics are swelling, broad chest, congenital heart disease, low hairline.
84
What is extra Y chromosome?
Extra Y chromosome is when there is an extra Y chromosome. Some characteristics are aggressiveness in behavior may have cognitive disabilities.
85
What is a gene?
A gene is a stretch of DNA that determines a certain trait.
86
What is a trait?
A trait is a noticeable characteristic (height, eye color, earlobe attachment).
87
What is an allele?
An Allele is an alternative form of a gene.
88
What are the dominant traits job?
Masks the other trait; the trait that shows if present. Represented by a capital letter.
89
What are the recessive traits job?
Recessive alleles for a particular trait will only show that trait when the dominant allele is not present. Represented by a lowercase letter.
90
What is a genotype?
The genotype is the set of genes in our DNA that is responsible for a particular trait.
91
What is a phenotype?
The phenotype is the physical expression, or characteristics, of that trait.
92
What is heterozygous?
A heterozygous individual is someone who has two different alleles.
93
What is homozygous?
A homozygous individual has two identical alleles.
94
What is heredity?
Heredity is when genetic traits are passed from one generation to the next.
95
What did Gregor Mendel discover through his plant peas?
Gregor Mendel, through his work on pea plants, discovered the fundamental laws of inheritance.
96
What is the Law of Dominance?
1. When one allele is dominant, it will always mask the recessive allele.
2. The recessive phenotype is only seen when two recessive alleles are present. (bb)
97
What is the Law of Segregation?
The alleles for a trait separate during meiosis and then randomly unite at fertilization.
98
What is the Law of Independent Assortment?
Dominant traits don’t have to travel together when traits are passed from parent to offspring.
99
How are unlinked genes created?
Due to the random orientation of homologous pairs during Meiosis I.
100
What are Punnet squares?
Punnett Squares help us determine possible phenotypes of offspring produced from the parent’s genotype combination.
101
What is Codominance?
Codominance is when both phenotypes from the parents are shown. Occurs when alleles of the same gene are present and shown in an organism.
102
What is Incomplete Dominance?
When there is a blend of dominant and recessive phenotypes shown in an offspring, this is called incomplete dominance.
103
Examples of Codominance?
Roan Cows, blood type
104
Examples of Incomplete Dominance?
Types of colors on flowers.
105
Why are most sex-linked traits inherited from the X-Chromosome?
Most sex-linked traits are inherited on the X-chromosomes simply because it is a lot bigger than the Y-chromosome (X-linked).
106
What is red-green color blindness?
A person cannot distinguish shades of red and green (usually blue-green).
107
What is hemophilia?
Hemophilia is a disorder where the blood cannot clot properly due to a deficiency of clotting factors. This results in abnormally heavy bleeding that will not stop, even from a small cut.
108
What is autosomal dominant?
1. Appears in both sexes.
2. Traits don't skip generations and unaffected parents don't transmit the genes.
3. Therefore, affected offspring must have an affected parent.
109
What is autosomal reccesive?
1. Appears in both sexes.
2. Traits skip generations.
3. Affected offspring are born to unaffected parents.
110
Is hemophilia a dominant or recessive disorder?
X-linked recessive disorder.
111
Is red-green color blindness a dominant or recessive disorder?
X-linked recessive disorder.
112
What is X-Linked Dominant?
1. Often, females are more affected than males.
2. Trait doesn't skip generations.
3. Affected sons must have affected mothers, affected fathers pass traits on to all of their daughters.
113
What is X-linked recessive?
1. Affected individuals are male.
2. Traits often skip generations.
3. Trait is never passed from father to son.
114
What is biodiversity?
Biodiversity is a measure of how many different species live in an ecosystem.
115
What is genetic diversity?
Genetic Diversity is the variety of genetic material within a species or a population.
116
What is species diversity?
The number and abundance of species present in different communities.
117
What is ecosystem diversity?
A variety of terrestrial and aquatic ecosystems is found in an area or on the earth.
118
What is camouflage?
Blending in with the environment.
119
What is seasonal change?
Changes body color with the changing seasons.
120
What is disruptive coloration?
A color pattern that is thought to disrupt the perceived contour of the body or parts of the body, thereby making the animal more difficult to see. Ex. Zebra
121
What is countershading?
The dorsal side (upper side) of the animal is darker than the ventral (lower) side. Ex. shark
122
What is cryptic coloration?
Coloration that allows an organism to match its background, therefore becoming less vulnerable to predator or recognition by prey. Ex. Walking stick
123
What is warning coloration?
The animal is not trying to conceal itself. The animal is advertising its presence. Ex. Bees, snakes
124
What are deceptive markings?
Markings or colors used to deceive (fool) a predator. Ex. Butterflies
125
What is mimicry?
Looking or sounding like another living organism.
126
What is Batesian Mimicry?
A harmless animal (the mimic) copies a known harmful animal (the model). Only one organism benefits from mimicry.
127
What is Mullerian Mimicry?
The monarch and the Viceroy butterfly both model and mimic are equally harmful to predators. Both organisms benefit from the mimicry.
128
What are some examples of animals that reproduce asexually?
Yeast, bacteria, and strawberries.
129
What is binary fission?
An asexual reproduction that primarily occurs in prokaryotes.
130
What is budding?
A form of asexual reproduction in yeast where a new cell grows out of the body of a parent.
131
What is a benign tumor?
An abnormal mass of cells that remains at its original site in the body.
132
What is a maglinant tumor?
An abnormal mass of cells that DOES NOT remain at its original site in the body and instead spreads throughout the body.
133
What are variations?
Variations are differences between individual members of a population.
134
What is a gene pool?
The sum of all the genetic information (genes) carried by members of a population.
135
What types of variation occur through in the gene pool?
Migration, Mutations, and Genetic Drift
136
What is fitness?
An organism’s ability to survive and reproduce in its specific environment.
137
What is Phylogeny?
Is the study of how living and extinct organisms are related to one another.
138
What are cladograms?
A clade is a group of species that includes a single common ancestor and all descendants of that ancestor- living and extinct.
139
What is speciation?
When a new species forms.
140
What is an outgroup?
A group of organisms not belonging to the group whose evolutionary relationships are being investigated.
141
What are derived characteristics?
The more derived characteristics two species share, the more recently they shared a common ancestor and the more closely they are related in evolutionary terms.
142
What is natural selection?
A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.
143
What is artificial selection?
Breeding organisms with specific traits in order to produce offspring with identical traits
144
Who was Charles Darwin?
English natural scientist who formulated a theory of evolution by natural selection.
145
Who was Jean-Baptiste Lamarck?
He proposed that by selective use or disuse of organs, organisms could acquire or lose certain traits which are then passed on to their children and future generations, eventually changing the species.
146
What is an adaptation?
Inherited characteristic that increases an organism's chance of survival
147
What is a node?
A place where a branch splits off from the rest of the cladogram, showing a speciation event
148
What is a root of a cladogram?
Represents common ancestor shared by all organisms
149
What is biogeography?
The study of the distribution of organisms around the world
150
What is embryology?
The study of embryos and their development
151
What is comparative anatomy?
The comparison of body structures in different species
152
What is a fossil record (planetology)?
Information about past life, including the structure of organisms, what they ate, what ate them, in what environment they lived, and the order in which they lived
153
What is comparative biochemistry?
Study of DNA, proteins, and chromosomes across species
154
What are homologous structures?
Structures that are similar in different species of common ancestry.
155
What are analogous structures?
Structures that do not have a common evolutionary origin but are similar in function
156
What are vestigial structures?
Remnants of organs or structures that had a function in an early ancestor
157
geographic isolation
Isolation between populations due to physical barriers
158
habitat isolation
Two species encounter each other rarely, or not at all, because they occupy different areas, even though not isolated by physical barriers
159
temporal isolation
form of reproductive isolation in which two populations reproduce at different times
160
mechanical isolation
Morphological differences can prevent successful mating
161
Behavioral isolation
Organisms don't recognize each other or the mating rituals
162
gamete isolation
Sperm cannot reach or fertilize egg
163
hybrid inviability
A postzygotic barrier in which hybrid zygotes fail to develop or to reach sexual maturity
164
hybrid sterility
Hybrid offspring mature but are infertile as adults
165
hybrid breakdown
Hybrid is fertile, but when they breed the next generation is sterile.
166
Allopatric speciation
The formation of new species in populations that are geographically isolated from one another.
167
Peripatric speciation
When a few individuals from a mainland population disperse to a new location remote from the original population and evolve separately.
168
Sympatric speciation
The formation of new species in populations that live in the same geographic area.
169
Parapatric speciation
Reproductive isolation evolves in neighboring populations that share small zones of contact and exhibit modest gene exchange
170
What is taxonomy?
The scientific study of how living things are classified.
171
What is evolution?
Change in a kind of organism over time; process by which modern organisms have descended from ancient organisms.
172
What is directional selection?
Occurs when natural selection favors one of the extreme variations of a trait.
173
What is stabilizing selection?
Natural selection that favors intermediate variants by acting against extreme phenotypes
174
What is disruptive selection?
Favors individuals at both extremes of the phenotypic range.
175
What is Hardy-Weinberg equilibrium?
The condition describing a non-evolving population (one that is in genetic equilibrium).
176
What is p (in hardy-weinberg)?
Frequency of dominant allele.
177
What is q (in hardy-weinberg)?
Frequency of recessive allele.
178
What is p2 (hardy-Weinberg equation)?
Homozygous dominant.
179
What is q2 (hardy-Weinberg equation)?
Homozygous recessive
180
What is pq (Hardy-Weinberg Equation)?
heterozygous
181
What is genetic drift?
A change in the allele frequency of a population as a result of chance events rather than natural selection.
182
What is the founder effect?
Change in allele frequencies as a result of the migration of a small subgroup of a population.
183
What is the bottleneck effect?
A change in allele frequency following a dramatic reduction in the size of a population.
184
What is antibiotic resistance?
Resistance evolving rapidly in many species of prokaryotes due to overuse of antibiotics.
