EXAM 4 Flashcards
(181 cards)
1
Q
The two cell divisions are called
A
Meiosis 1 / Meiosis 2
2
Q
What happens at the end of meiosis cell division
A
A single parent cell has produced four daughter cells
3
Q
How many chromosomes do sperm and egg have
A
23 each
4
Q
What are the three main characteristics of meiotic cell division
A
- Meiotic cell division results in four daughter cells instead of two
- Each of the four daughter cells contains half the number of chromosomes as the parent cell instead of the same number
- Each daughter cell is genetically unique instead of genetically identically
5
Q
What are gametes
A
Sperm and egg
6
Q
Gametes are produced by a form of cell division called
A
Meiotic cell division (meiosis)
7
Q
What is a phenotype
A
Physical expression of a gene
Ex: red hair, blonde hair, lactose intolerant
8
Q
What is a genotype
A
Total collection of genes
Ex: AA or aa (homozygous) Aa (heterozygous)
9
Q
What is an allele
A
Alternative version of gene
Ex: A or a
10
Q
What is an example of homozygous vs heterozygous
A
Homozygous: AA or aa
Heterozygous: Aa
11
Q
Are somatic cells diploid or haploid
A
Diploid
12
Q
At a biochemical level, it’s not A’s that are capital or lowercase. What is it?
A
It’s the dna that is different
13
Q
By definition, the sex that has the bigger gamete is
A
Egg (female)
14
Q
Fertilization goes from __ to __
A
Haploid to diploid
15
Q
How are gametes produced
A
Meiosis
16
Q
How do plants reproduce
A
Asexually
17
Q
How do you go from a single cell diploid mouse zygote to a full size mouse
A
Mitosis
18
Q
How does a spider plant reproduce
A
Spider plants reproduce by making new, identical baby spider plants. The plant will release plantlets that have the same DNA as the parent. If you plant the plantlets, you have a new spider plant
19
Q
How does meiosis 2 end
A
Four different cells with haploid chromosome numbers
20
Q
What is the haploid number
A
23
21
Q
What is the diploid number
A
46
22
Q
How many chromosomes do gametes have
A
Sperm: 23
Egg: 23
Human: 23
23
Q
If the sex chromosome are x and x, what gender is the baby
A
Female
24
Q
If the sex chromosome are x and y, what is the gender of the baby
A
Boy
25
In meiosis, how many rounds of DNA synthesis are done and where does it occur
One round of dna synthesis
Meiosis 1
26
Meiosis goes from __ to __
Diploid to haploid
27
What are the maternal and paternal pair of chromosomes called
Homologous chromosomes
28
What are the stages of interphase
G1
S
G2
29
What are the main characteristics of meiosis
1. Results in four cells
2. Genetically different
3. Four cells produced contain half the number of chromosome instead of same number
30
What can increase genetic diversity
Crossing over and random alignment
31
What happens during prophase 1
- chromosomes condense
-line up with homologous pairs
-crossing over
-nuclear envelope disappears
32
What happens in prometaphase 1
Spindles attach to kinetochores on chromosome
33
What happens during metaphase 1
Homologous pairs line up in the middle
Random alignment
Side by side
34
What happens during anaphase 1
Homologous chromosomes separate, but sister chromatids do not separate
35
What happens during telophase/ cytokinesis 1
Two new cells form
36
What happens during prophase 2
Nuclear envelope breaks down
Chromosome condense
No dna synthesis
37
What happens during prometaphase 2
Spindles attach to kinetochores on chromosome
38
What happens during metaphase 2
Sister chromatids align in middle
Single file
39
What happens during anaphase 2
Sister chromatids separate
40
What happens during telophase/ cytokinesis 2
The nuclear envelope reforms and four genetically different gametes are produced
41
What is the process called where homologous chromosomes pair with each other, coming together to lie side by side
Synapsis
42
What is the process that puts n and n together to go back to 2n
Fertilization
43
What needs to happen for meiosis to occur
Interphase needs to occur before meiosis begins
44
What organism can do meiosis
Anything with a true nucleus
Not prokaryotes
45
Who is known as the father of genetics
Gregor Mendel
46
What was Mendel known for crossing
Peas
47
What is the predicted ratio for monohybrid cross
3:1
48
What is the predicted ratio for dihybrid cross
9:3:3:3:1
49
Consider the characteristics for monohybrid and dihybrid cross. How many pairs are involved with each
A single pair of genes is involved in monohybrid
Two pairs of genes are involved
50
If you cross yellow and green pea, what color will the offspring be
Yellow
51
What is true-breeding
Physical appearance of the offspring in each successive generation is identical to the previous one
52
What is incomplete dominance and give an example
Incomplete dominance occurs when one trait is not completely dominant over the other trait
Ex: red and white flower mate to produce pink flower
53
What is codominance and give an example
Codominance occurs when both traits are full expressed. This usually results in spotted or speckled pattern in offspring
Ex: red and white flower mate to produce white/red flower
54
What are Mendel’s laws
Law of dominance
Law of segregation
Law of independent assort,ent
55
What does the law of dominance state
A dominant gene will express itself over the recessive gene
Ex: Paren plant: Tall (TT) X Dwarf (tt) F1 gen will be Tall
56
What is the law of segregation
When an organism produces gametes (sperm and egg), the two copies of each gene it has (one from each parent) are separated. This means each gamete gets just one of the two gene copies
57
What is the law of assortment
That genes for one trait are not inherited with another trait
58
What are the exceptions to Mendel’s laws
Incomplete dominance
Codominance
Multiple alleles
Epistasis
Polygenic inheritance
Environmental effect
59
Is truebreeding heterozygous or homozygous
Homozygous
60
What is an example of truebreeding
100% yellow peas generation after generation
100% green peas generation after generation
61
What is the process to mate peas
1. You cut the male genitalia off the flower
2. Then you have two separate plants: flower on female parent and flower on male parent. You would take a paintbrush and rub the male pollen on female
3. After fertilization, a small cloth bag is tied around the fertilized plant to prevent stray pollen from enetering
62
How does phenotype relate to character and trait
Phenotype is a combination of character and trait.
Phenotype: blonde hair
Character: hair color
Trait: what color the hair
63
Give an example of character and trait regarding peas
Character: pea color
Trait: yellow or green
64
Do the foil method for HhSs x hhss
F HS
O Hs
I hS
L ha
65
How do you find the genotype ratio
Genotype ratio would be the letter that represent alleles
66
Make a punnet square for Hh x hh
What is the genotype ratio and the phenotype ration
Genotype 2Hh : 2hh
Phenotype 2 hairy : 2 hairless
67
If the answer is always would the answer be true or false
False
68
What is the phenotype and genotype for type A blood
P: type a
G: ꞮA ꞮA or ꞮA i
69
What is the phenotype and genotype for type b blood
P: type b
G: ꞮB ꞮB or ꞮB i
70
What is the phenotype and genotype for type ab blood
P: type AB
G: ꞮA ꞮB
71
What is the genotype and phenotype for type O blood
P: type O
G: ii
72
In a pedigree what shape is female and what shape is male
Female: circle
Male: square
73
Open symbols vs darkened symbol on a pedigree
Open symbol means not affected
Darkened symbol means affected
74
What is example of epistasis
Desk with surge protector. If you unplug the surge but turn on the computer, nothing will work. If you connect the surge, the computer can be turned on or off
75
Is a virus a prokaryote or eukaryote?
Neither
76
How does a virus cell require to reproduce
A host cell
77
Explain the key and lock analogy for a virus
On the outside of a virus, they have “keys”. The keys will fit on the lock so genetic information can be injected
78
What is zoonotic
A disease causing agent that is transmitted to humans from other animals
79
What are bacterial viruses called
Bacteriophage or phage
80
What microscope do you see a virus under
Electron microscope
81
Why would a virus take part of the host cell
To hide within the plasma membrane
82
What is the process for the lytic pathway
In this pathway, the virus attacks to the bacterium and injects dna/rna. After an hour it will burst open to release more phages
83
What is the process for the lysogenic pathway
The phage injects genetic material but this time the genetic material stays hidden in the host’s genetic material. When the host makes new cells, it replicates its own genetic material and the virus genetic material
84
What is a capsid
Protein shell that surrounds the genome
85
When does the viral envelope come
Envelope comes from modified host membrane (after infection of the host cell)
86
What is the genetic material in viruses
Rna or dna
87
What is host range
A range of organisms that a virus can infect
88
What is an example of narrow host range
Measles
89
What is an example of wide host range (infect multiple species)
West Nile virus
90
What receptors can HIV bind to
Only some immune cells
91
What cells does the human cold virus infect
Human cold virus infect only the cells lining upper respiratory tract
92
What is the main difference between lytic cycle and lysogenic cycle
Virus genes remained dormant in lysogenic and in the lytic cycle the virus take over the host cell to replicate
93
How can a virus damage or kill cells
By causing the release of hydrolytic enzymes from host lysosomes
94
Are antibiotics effective against viruses? True or False
False
95
Are antibiotics effective against bacterial infection? True or False
True
96
What are vaccines
Harmless derivatives that stimulate the immune system
97
What is herd immunity
Occurs when a portion of individuals in a population are immune to a disease and stop its spread.
Ex: if a few people have a disease that can be spread then most of the population will get the shot
98
What is speciation
The process by which one species become two species
99
What is an example of same species
Dogs. They are all the same species even though they look different
100
Can two different species breed and have offspring?
Yes
101
If a donkey and zebra have a child, what is a characteristic of the zonky
It will not be fertile
102
Are all humans one species? True or false
True
103
What does prezygotic barrier mean
Barriers that occur before you can make a zygote
104
What are the two factors that cause reproductive isolation
Prezygotic barriers
Postzygotic barriers
105
What does postzygotic barrier mean
You mate and fertilize to create a zygote
106
What are prezygotic barriers
Behavioral isolation
Temporal isolation
Habitat/ecological
Geographic
Gametic isolation
Mechanical isolation
107
What is an example of habitat isolation
Organisms that live in the same area but their habitats aren’t the same
You could have two species of amphibians living in the same area but one could prefer aquatic environment and one prefer terrestrial environment
108
What is an example of temporal isolation
Species can breed at different times, seasons, or years
109
What is an example of behavioral isolation
Species can have different behaviors that isolate themselves
Ex: birds having different songs. This can prevent males from attracting females
110
What is a biology example for behavioral isolation
Eastern and western meadowlark
111
Is there any organism that lives forever
No
112
What is evolution
At a genetic level, evolution is a change in the frequency of an allele or a genotype from one generation to the next
113
Does evolution evolve individuals or populations
Populations
114
What is population genetics
Interbreeding groups of organisms of the same species in same geographical area
115
What does gene pool consist of
All alleles present in all individuals in the species. The human gene includes alleles that cause differences in skin color, hair type, eye color…etc
116
If a somatic cell has 10 chromosomes, then each gamete would have how many chromosomes
5
117
In meiosis, homologous chromosomes move to opposite sides of the cell in
Anaphase 1
118
A 9:3:3:1 phenotypic ratio is characteristic of what cross
Dihybrid cross
119
In peas, purple flowers are dominant over white flowers. If two heterozygotes are crossed, what fraction of the population will have white flowers?
1 out of 4 (25%)
120
In meiosis, homologous chromosomes align on the metaphase plate in
Meiosis 1
121
What is reduced hybrid fertility
When you mate two different species, the offspring will become sterile (unable to fertilize)
Example: donkey + horse = mule
122
What is hybrid breakdown
Skips one generation then ends
123
What is extant species
Alive right now
124
How does hair color relate to gene pool
Alleles that cause brown hair are drawn from that gene pool
125
What is present in gene pool
All alleles present in all individuals in a population or species
126
What is microevolution
Change in allele frequencies in a population over time
127
What is macro evolution
Multiple small changes over time lead to new species
128
What are two sources of genetic variation
Mutations and recombination
129
Mutations can be ___ or ___
Somatic or germ-line
130
What is a somatic mutation
Occur in Nonreproductive cells. Only affect one individual
131
What are Germline mutations
Occur in reproductive cells. Passed on to the next generation
132
What is allele frequency
Proportion among all the alleles of a gene in a population
133
What is an example of the hardy weinburg theorem
Imagine a scale perfectly balanced
134
Can speciation occur without natural selection?
Yes. Speciation can occur without or with natural selection
135
What is speciation
Formation of new species from an existing species
136
What is a species?
Group of organisms that breed together with one another and produce fertile offspring
137
What is biological species concept
BSC defines members of the same species can mate and have babies that can also grow up and have their own babies (dogs and dogs). Conversely, two different species cannot produce viable, fertile offspring (dogs and cats)
138
What is the key to biological species concept
Reproductive isolation
139
What causes reproductive isolation
Reproductive isolation is caused by barriers to reproduction before or after egg fertilization
140
What is an example of geographic isolation
Polar and grizzly bears are unable to produce offspring because they are not geographically located near each other
141
What is an example of gametic isolation
Incompatibility between pollen and flower, such that fertilization fails to take place
142
What is an example of mechanical isolation
Snails unable to mate due to physical incompatibility
143
Speciation is the by product of
Genetic divergence of populations
144
What is allopatric speciation
A population is isolated geographically
145
What are two examples of allopatric speciation
Dispersal and vicariance
146
What is an example of dispersal isolation
Individuals colonize an island
Ex: the first finches arriving to Galapagos island from South America
147
What is an example of vicariance isolation
Geographic barriers arise within population, separating them into two
Ex: a river, mountain
148
What is sympatric speciation
Speciation in the same geographic place
149
How does sympatric speciation occur
Speciation occurs in geographically overlapping populations when biological factors such as chromosomal changes (mutations) and nonrandom mating
150
The fossil record shows two types of speciation (the pace of speciation) :
Punctuated equilibrium and gradual model
151
What is an example of the punctuated model
Rapid evolution then nothing. An example can be bacteria. You start with a yellow shell then time passes and you have the full formed shell.
152
What is an example of gradual model
Shopworn changes over time. More common in animals. You start with a yellow shell and as time passes, details will be added
153
What are two sources of genetic variation
Mutation and recombination
154
Mutations can be __ or __
Somatic or germ-line
155
Mutations can be __ or __
Somatic or germ-line
156
What is an example of somatic mutation
Occur in non reproductive cells. Somatic cells on,y affect one individual
157
What is an example of germline mutations
Occur in reproductive cells. Passed on to the next generation
158
__ are the ultimate source of all genetic variation
__ shuffles ___ into new combinations
Mutations
Recombination
Mutations
159
Give an example of allele frequency (jelly beans)
Imagine you have a big jar of jelly beans. These jelly beans come in different colors: red and b,use. Now let’s say there are 100 jellybeans in the jar. 30 of them are red while the rest are blue. Allele frequency is like looking at how many red are compared to total number of jellybeans.
160
If you have a total of 100 jelly beans and 30 of them are red. What is the allele frequency of red jellybeans?
30 out of 100 or 30%
161
Give an example of the hardy Weinberg theorem (scale)
Imagine a scale is perfectly balanced, showing how common different alleles are in a population. This theorem describes a population where that scale stays perfectly balanced meaning no evolution happens
162
What is the Hardy Weinberg equilibrium
p^2 + 2pq + q^2 = 1
163
Explain the symbols in the hardy Weinberg equilibrium
p^2 (homozygous dominant genotype)
+ 2pq
+ q^2 (homozygous recessive genotype)
= 1
164
What is an example of homozygous
AA or aa
165
What is an example of heterozygous
Aa
166
What are the hardy Weinberg conditions
No mutation
Random mating
No natural selection
Large population size
No gene flow (migration)
167
What’s are the three factors that alter allele frequency and bring about most evolutionary change
Natural selection
Genetic drift
Gene flow
168
What are the three main types of natural selection
Directional selection
Disruptive selection
Stabilizing selection
169
What is an example of directional selection
White mice and black mice get put in a dark forest. The white mice will stand out so that population will die out
170
What is an example of disruptive selection
A squirrel has shirt tails to help keep predators from catching them. Long tails are good for balancing in trees. Medium tails don’t help
171
What is an ex apple of stabilizing selection
A good example is provided by birth weight. If a baby is very small, it’s chances of survival after birth are low. If baby is very big, there may be complications during delivery. The optimal weight is between two extremes
172
What is intersexual selection
Members of one sex compete with one another for access to the other sex
173
What is genetic drift
Random leads to changes in allele frequency. With genetic drift, the organism isn’t more fit they just won the game of chance
174
What is an example of genetic drift
Insects are on the sidewalk and you walk through and squash them. The ones that survived weren’t better adapted , they were lucky
175
What is bottleneck effect
A disaster caused by a sudden change in the environment may reduce population size
176
Give an example of bottleneck effect
Consider a natural disaster, such as a forest fire. The surviving organisms weren’t better adapted, they were in an area where they weren’t affected
177
What is the founder effect
When a few individuals become isolated from a larger population (by genetic drift or other reasons)
178
What population is more vulnerable to genetic drift? Big or small
Small
179
Give an example of founder effect
The few organisms that arrive to start a new population do not represent the original population that they came from
180
What is gene flow
Movement of individuals from one population to another
181
What is an example of gene flow
Pollination of a new population with an allele from a different population or a river carrying fish to a new lake
