Science Midterm Exam - Physics/Biology Flashcards
1
Q
What is an equation’s use?
A
Equations are used to calculate quantities, using mathematical concepts
2
Q
What is the equation for average speed?
A
Speed = distance/time
3
Q
Define speed
A
How fast the position of an object moves over time (scalar quantity)
4
Q
Why do we use “average speed”?
A
Most things do not travel at a consistent speed (unless they are on cruise control) so average is used
5
Q
What is instantaneous speed?
A
How fast an object is travelling at a particular moment. ie - reading speed from a speedometer.
6
Q
Is average speed and speed the same?
A
Yes
7
Q
What units are speed measured in?
A
m/s (metres per second) or km/h (kilometers per hour)
8
Q
If something is stationary, it is…
A
Stationary relative to us
9
Q
What is a scalar quantity
A
Numerical value (eg. weight, speed, “70km/h”)
10
Q
What is a vector quantity
A
Speed and direction (eg. “80km/h going North”)
11
Q
How to get m/s to km/h?
A
x3.6
12
Q
How to get km/h to m/s?
A
/3.6
13
Q
What is velocity?
A
Speed with direction (eg. 5 km/h South)
14
Q
What is the equation for velocity?
A
Same as speed (s=d/t)
15
Q
What is the equation for distance?
A
Distance = speed x time
16
Q
What is the equation for time?
A
Time = distance / speed
17
Q
What is acceleration?
A
Increasing change in motion, increase in speed
18
Q
What is deceleration?
A
Decreasing speed
19
Q
Name types of relevant graphs
A
Distance/Time, Displacement/Time
(and speed/time but not as relevant)
20
Q
In Distance/Time graph, what does a horizontal line mean?
A
Stationary
21
Q
In a graph, what does a upward curve mean
A
Accelerating
22
Q
In Distance/Time graph, what does a leveling curve mean
A
Slowing/stopping
23
Q
In Distance/Time graph, what does a increasing line mean
A
Constant, fast speed
24
Q
In a displacement/time graph, what does a horizontal line mean
A
Constant Speed
25
What is mass?
The quantity of matter in a given object
26
What can mass be measured by?
Kg, G
27
What is mass vs weight?
Weight is mass relative to gravity, mass is amount of matter in object
28
What are forces measured in?
N = Newtons
29
What are some examples of forces?
Gravity, thrust, friction, elastic tension
30
What is the acceleration due to gravity on Earth?
Approximately 10m/s/s
31
How many laws did Newton theorize?
3
32
What does an object's inertia depend on?
Speed and Mass
33
What is the law of inertia?
A body at rest will remain at rest, and a body in motion will remain in motion unless an UNBALANCED force acts upon it
34
What is the law of acceleration?
An object travelling in a straight line will continue to do so unless acted upon by an unbalanced force
35
What is the law of interaction?
When two bodies interact, they apply forces to one another that are equal in magnitude and opposite in direction.
36
What impacts acceleration?
Size of force, mass of object
37
What quantity is acceleration measured in?
m/s/s (meters per second per second)
38
How do you calculate acceleration?
V - V0 (initial velocity) / time
39
What is energy measured in?
Joules = J
40
Examples of energy
elastic, kinetic, gravitational potential
41
What are the two categories of energy?
Kinetic, potential
42
Name examples of kinetic energy types
Heat, light, sound
43
Name examples of potential energy
Gravitational, elastic, chemical
44
What is energy transformation?
Energy goes from one energy type to another. EG: Kinetic to heat, gravitational potential to kinetic
45
What is energy transfer?
Energy is maintained but transferred/shifted from one object to another
EG: Punching a bag - kinetic energy transfer from fit to bag
46
What is EPgrav, and how is it calculated?
Gravitational potential energy:
Mass (kg) x Gravity (N) x Height (m)
47
What is EK, and how is it calculated?
Kinetic energy:
1/2 x Mass x Velocity²
48
How is EPgrav increased?
With increased height
49
How is EK increased?
With increased speed
50
How is EPelastic increased?
With increased bending, stretching, or compression
51
What is the Law of Conservation?
Energy cannot be created nor destroyed, only transformed or transferred.
52
How can energy transfer appear?
Through heat, light (sparks), and mechanical (collision). No energy is lost, just transformed.
53
What is an action force?
Refers to the force exerted by one object on another object in a particular interaction.
54
What does a reaction force do?
Acts in the opposite direction to the action force.
55
How many alleles are in a sector of genes?
2 alleles
56
What are genes?
A sector of code that lies in the DNA. It contains alleles that determine the physical attributes of a person.
57
What is non-mendelian?
Recessive
58
What is mendelian?
Dominant
59
What sex can be a carrier for x-linked diseases?
Female as they have two X chromosomes
60
What sex chromosomes do males have?
X Y
61
What sex chromosomes do females have?
X X
62
What is inheritance?
The passing down of physical traits through a family line. Characteristics come from parents
63
What do we call the passing of traits?
Heredity
64
What type of cell division allows for traits to be passed down?
Meiosis, but can also be through mitosis
65
How do we represent dominant traits?
A capital letter, eg. GG
66
How do we represent recessive traits?
A lowercase letter, eg. gg
67
What are the two types of genetic inheritance?
Dominant and Recessive
68
What is a recessive trait?
A characteristic that will ONLY show is both lowercase letters are shown. Example: gg will show the recessive gene, but gG will show dominate (even though there is a recessive) as dominant dominates overall.
69
What is a dominant trait?
A characteristic that will always show is presented in the allele. Example: Gg will show a dominant trait as G overpowers g.
GG is also dominant
70
Describe a genotype
The genes given to the offspring, the letters given to represent them (eg. gg)
71
How do you write out a genotype?
Use the letters, so either GG, gg, Gg, gG
72
Describe a phenotype
The physical appearance expressed in the offspring.
73
How do you write a phenotype?
Refer to specific physical attributes.
EXAMPLE: Red hair = 25%
Brown = 75%
74
What is heterozygous?
Having two different alleles = one dominant and one recessive (one uppercase and one lowercase)
75
What is homozygous?
Two of the same alleles = two dominant or two recessives (eg. AA or aa)
76
What is a hereditary carrier?
An organism that has inherited a recessive allele from a parent for a trait or mutation. It is not typically shown in the carrier organism, but its offspring may inherit that trait.
77
Define DNA
Organic material is found in the cells of most living things. It is the genetic code for an organism and gives information on an organism's traits.
78
How do you spell DNA?
Deoxyribonucleic Acid
79
Who theorized the structure of DNA?
Watson & Crick
80
What is the modern model of DNA called?
Double Helix structure
81
What are things that can be inherited from a parent?
Alleles, genetic disorders, traits, characteristics eg. height
82
How many backbones are in the double helix model?
2
83
What are DNA's backbones made of?
Sugar-phosphate
84
Where in the cell is DNA located?
Nucleus
85
What is a nucleotide?
Organic molecules in DNA. They are a repeating sequence made of sugar, phosphate, and nitrogen
86
What are base pairs?
Complimentary pairs, bonded by hydrogen, are found in genes. They form DNA's building blocks and hold the structure together. They are nitrogenous bases.
87
What pairs with adenine?
Thymine
88
What pairs with guanine?
Cytosine
89
What pairs with thymine?
Adenine
90
What pairs with cytosine?
Guanine
91
Why are base pairs bonded by hydrogen?
As it is weak, it allows DNA to replicate
92
What type of chemical bond joins the two DNA bases?
Hydrogen
93
Which nucleotide parts make up the outside of the DNA?
Sugar, phosphate
94
Which nucleotide parts make up the inside of the DNA?
Nitrogen
95
How many chromosomes does a human have, and what are they?
23 total pairs, 46 induvidual. 22 pairs of autosomes and 1 pair of sex (X, Y) chromosomes.
96
What is the acronym for cell division?
IPMAT+C
97
What is mitosis?
A type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus. Reproduction, repair, and growth
98
Why is mitosis important?
Without it, dead cells would never be replaced, organisms would never grow or heal.
99
What is meiosis?
2 rounds of cell division, ending up with half the amount of DNA as it is half from each parent. Meiosis can introduce genetic variation, important as it creates diversity in the population
100
What is unique about homologous chromosomes?
Homologous chromosomes can swap parts to look different (random process)
101
What is a haploid cell?
The daughter cells of meiosis (half set of DNA)
102
Define a diploid cell
The daughter cells of mitosis (full set of DNA)
103
Why must haploid cells have half the amount of DNA?
If egg and sperm have two full sets, then there is too much DNA. Otherwise, mutations can occur.
104
What is a chromosome?
An X structure is made of DNA. They allow DNA to be accurately replicated.
105
What is a homologous chromosome?
Two chromosomes in a pair, one from mother and one from father.
106
Define a chromatid
The single strand of a chromosome
107
What are chromosomes made up of?
DNA tightly coiled many times around proteins called histones
108
Define sister chromatids
The two chromatids are in the same chromosome.
109
Define a centromere
Part of the chromosome where spindles attach.
110
What is the role of meiosis?
To introduce genetic diversity
111
Describe interphase
Pre-mitosis where DNA replication occurs
112
Describe prophase
Prophase prepares the cell for division. Parent cell begins to break the nucleus down, chromosomes become visible and organised
113
Describe metaphase
Chromosomes line up in the middle of the cell to allow them to separate to opposite ends of the cell. Chromatids prepare to be broken apart and spindle fibres come out of centrioles and attach, preparing to separate the chromosomes.
114
Describe anaphase
Sister chromatids (previously a chromosome) separate due to spindle fibres pulling them apart. Chromatids separated to opposite ends of the cell
115
Describe telophase
* Daughter cells that are formed are beginning to separate
* Nucleus reforms in each cell around DNA
* Not completely separated
* Centrioles disappear
116
Describe cytokinesis
* Daughter cells separate fully
* DNA disorganises and is no longer visible
117
What is a centriole?
Organisims inside a cell that aid organisation
118
What is a zygote?
A fertilized cell
119
What is a gamete?
The reproductive cell of an animal or a plant
120
Define a somatic cell
Any cells in the body that are not involved in reproduction. They are diploid cells that contain 46 chromosomes arranged in 23 pairs, 22 autosomes and 1 sex chromosome (e.g xy, xx)
121
Define a gamete cell
Reproductive cells such as sperm or egg. They are haploid and contain no pairs
122
What is a sex chromosome
Determine sex of a person, are one pair e.g XY or XX
123
Define autosome
A chromosome that isn't used to determine the sex of someone. There are 22 pairs of autosomes in a cell. The other pair is a sex cell
124
Where are alleles found?
On a chromosome
125
What is an allele?
A variant of a gene for a trait. They are located in chromosomes and there are two alleles per sector of gene.
126
What is natural selection?
It is a mechanism of evolution. It "chooses" which organisms can survive based on their phenotype and genotype. It occurs randomly but follows a pattern in which it wipes out.
127
What is artificial selection?
The identification, by humans, of desirable traits. This might include fast running or good vision. Humans may choose to breed these traits down generations, "weeding" out those inferior.
128
What is a mutation?
An alteration in the genetic sequence that varies an organism's phenotype.
129
What can cause mutations?
Fluctuations in weather, UV radiation, chemical exposure
130
What is an abiotic factor?
Non-living, physical, or chemical aspects of environment eg. bushfires, rain, temperature.
131
What is a biotic factor?
Living pressures eg. predators, algae, snakes
132
How can organisms adapt?
As the population changes, genetic traits will appear more commonly in organisms. These traits have been passed down generations as they have allowed the previous to survive. The next generation takes these traits among others to adapt to their surrounding environment.
