BIO EXAM (all) Flashcards
1
Q
M6 (Quiz) - What language does the word “evolution” (originate from)?
A
Latin (evolvere)
2
Q
M6 (Quiz) - The formation of new organisms by the transformation of ancestral forms is termed:
A
Organic evolution
3
Q
M6 (Quiz) - Which system did Linneaus invent and what did it do?
A
Binomial. Classified organisms into genera and species.
4
Q
M6 (Quiz) - What was Cuvier’s Theory of Catastrophism
A
Explained different assemblages of extinct organisms found in layers of earth strata at different depths
5
Q
M6 (Quiz) - What is the name given for all those natural agencies which comprise the mechanisms of evolution and their products?
A
Processes
6
Q
M6 (Quiz) - Where is it believed that Galapagos Finches originated from?
A
Ecuador
7
Q
M6 (Quiz) - What is a sequential relationship of fossils?
A
When comparing fossils of similar organisms in a series of older to younger rock strata trends one sees progressive changes in body form
8
Q
M6 (Quiz) - The independent evolution of similarity between species as a result of their having similar ecological roles and selection pressures is referred to as:
A
Convergent evolution
9
Q
M6 (Quiz) - What are the heritable novelties thtat evolution requires?
A
Genetic Drift
Mutation
Non-random mating
10
Q
M6 (Quiz) - Which theorem states ‘a population’s gene and genotype frequencies don’t change from generation to generation, unless acted on by agents of evolution’?
A
The Hardy-Weinberg Theorem
11
Q
M6 (Quiz) - Over its geographic range, a species generally has many populations, which taken together are termed a:
A
Metapopulation
12
Q
M6 (Quiz) - What is punctured equilibrium?
A
How fossils show periods of rapid evolution followed by long periods of little change
13
Q
Module 5 (Quiz) - How did Krebs define ecology?
A
The scientific study of the interactions that determine the distribution and abundance of organisms
14
Q
Module 5 (Quiz) - What is the simplest component of the ecological hierarchy?
A
The individual / organism
15
Q
Module 5 (Quiz) - What happens to complexity of processes and interactions as we move through the ecological hierarchy?
A
It becomes more complex
16
Q
Module 5 (Quiz) - What are the two types of explanation recognised in ecology?
A
i) Proximal
ii) Ultimate
17
Q
Module 5 (Quiz) - What kind of relationship do organisms and the environment have?
A
Interdependent
18
Q
Module 5 (Quiz) - In some situations humans have managed to dramatically increase productivity by supplementing the factor that is most:
A
Limiting
19
Q
Module 5 (Quiz) - Producers convert energy from the environment (inorganic sources) into high energy _______ bonds
A
Carbon
20
Q
Module 5 (Quiz) - What do endotherms expend a large amount of energy to maintain?
A
Body temperature (internal)
21
Q
Module 5 (Quiz) - Which of the following IS NOT one of the important biological conversions of nitrogen critical to the nitrogen cycle?
a. nitrogen fixation
b. denitrification.
c. nitrogen leaching
d. nitrification
A
c. Nitrogen leaching
22
Q
Module 5 (Quiz) - The zone including all the water above the bottom of the ocean and the organisms that live there is called the ______ zone?
A
Pelagic
23
Q
Module 5 (Quiz) - Which of the following IS NOT one of the three major cultural developments that are generally recognised to have had a significant effect on early human ecology and relationships to the environment:
a. aqueducts
b. the use of tools
c. the development of language
d. development of social organisation and cooperation
A
a. Aqueducts
24
Q
Module 5 (Quiz) - Which of the following IS NOT one of the main types of pollutants which are generally recognised:
a. substances that occur naturally in the environment but which may not be present in high quantities
b. substances that are naturally occurring but are not normally free in environment
c. substances that are not naturally occurring in the environment
d. all of the above
A
d. All of the above
25
Module 3 (Energy Quiz) - If ΔG is < 0, a reaction will:
Occur spontaneously
26
Module 3 (Energy Quiz) - In the equation G = H – TS, what does each letter stand for?
```
G = Free energy (proportion of energy that can be used for work)
H = Total energy
T = Absolute temperature
S = Entropy
```
27
Module 3 (Energy Quiz) - Reactions that release energy are called:
Exergonic
28
Module 3 (Energy Quiz) - What does 'entropy' refer to?
A measure of disorder or randomness
29
Module 3 (Energy Quiz) - What is the basic reaction for respiration?
Organic molecules + O2 → H2O + CO2 + energy
30
Module 3 (Energy Quiz) - Which of the following IS NOT one of the three main kinds of cellular work:
Select one:
a. transport
b. mechanical
c. chemical
d. casual
Casual
31
Module 3 (Energy Quiz) - Can energy be destroyed or created?
No
32
Module 3 (Energy Quiz) - List 3 functions of metabolism
i) Convert nutrients to molecules
ii) Obtain energy
iii) Make cell structures (eg proteins, DNA, membranes, etc.)
33
Module 3 (Energy Quiz) - What are the two most important metabolic processes from a cycle of molecules and energy in life?
Photosynthesis and respiration
34
Module 3 (Energy Quiz) - What are the two most important metabolic processes from a cycle of molecules and energy in life?
Photosynthesis and respiration
35
Module 3 (Energy Quiz) - The chemical energy released by __________ is captured in the conversion of ADP back to ATP.
Catabolism
36
Module 3 (Energy Quiz) - ATP is typically used to provide energy by removal of its:
Terminal phosphate group
37
Module 3 (Energy Quiz) - When are reactions said to be at equilibrium?
When their forward and back reactions occur at the same time
38
Module 3 (Energy Quiz) - The exergonic liberation of the terminal phosphate from the ATP molecule requires water and thus it is known as:
A hydrolysis reaction
39
Module 3 (Energy Quiz) - The proportion of energy that can be used to perform work is referred to as:
Free energy
40
Module 3 (Energy) - What is the difference between an anabolic and catabolic pathway?
Anabolic: Consume energy in building molecules
Catabolism: Release energy on breaking down complex molecules
41
Module 3 (Energy) - What is kinetic, potential and chemical energy?
i) Kinetic: Energy of motion
ii) Potential: Stored energy (due to location or structure)
iii) Chemical: Conversion of simple molecules to more complex molecules involves the storage of energy in these molecules, which is referred to as chemical energy
42
Module 3 (Energy) - What is bioenergetics?
The study of how organisms manage their energy resources
43
Module 3 (Energy) - What is thermodynamics? What is the First Law of Thermodynamics?
The study of energy transformations in matter.
The First Law suggests that the Universe is constant; energy can be transferred or transformed; Energy cannot be created or destroyed
44
Module 3 (Energy) - What is thermodynamics? What is the Second Law of Thermodynamics?
Every energy transfer increases the entropy (disorder or randomness) of the universe.
45
Module 3 (Energy) - What happens to free energy at equilibrium?
It is at its lowest, and does not change.
46
Module 3 (Energy) - What does ΔG < 0 and ΔG > 0 mean?
ΔG < 0 = the release (exergonic) of free energy
ΔG > 0 = the consumption (endergonic) of free energy
ΔG = 0 = equilibrium
47
Module 3 (Energy) - What is metabolic disequilibrium?
If a cell is at equlibrium, it is dead.
48
Module 3 (Energy) - How does ATP work?
It is used to provide energy by removal of its terminal phosphate group, providing Adenosine Di Phosphate and inorganic phosphate (Pi). This hydrolysis provides free energy and is coupled to endergonic reactions to provide energy necessary for them to occur.
The ATP drives cellular work.
The chemical energy released by catabolism is captured in the conversion of ADP back to ATP.
49
Module 3 (Energy) - What kind of reaction is respiration and photosynthesis and photosynthesis (endergonic or exergonic)?
Respiration: spontanteous / exergonic
Photosynthesis: spontaneous backwards / endergonic
50
Module 3 (Energy) - What is activation energy?
The energy that is required to activate free energy (ie pushing a ball down a slide). Energy from the sun is the activation energy in photosynthesis.
51
Module 3 (Energy) - What is energy?
Energy is everything. It is the ability to do work.
52
Module 3 (Enzymes Quiz) - Since most reactions could not occur at an appreciable rate without catalysis by enzymes, cells can control metabolism by:
Activation or inhibition of enzymes
53
Module 3 (Enzymes Quiz) - What can feedback inhibition prevent?
A cell wasting chemical resources
54
Module 3 (Enzymes Quiz) - The 3D structure of an enzyme is related to physical factors such as temperature and pH, since these factors may change the chemical bonds that _______ the shape of the enzyme
Stabilise
55
Module 3 (Enzymes Quiz) - What is allosteric regulation?
Where molecules alter an enzymes functional site by binding onto it at another site
56
Module 3 (Enzymes Quiz) - What is the optimal pH for an enzyme inside the human stomach?
2
57
Module 3 (Enzymes Quiz) - What is it called when a subtrate binds to an enzyme?
Enzyme-substrate complex
58
Module 3 (Enzymes Quiz) - The active site of an enzyme has a precise 3D shape, in which certain chemical groupings are arranged in such a way as to encourage a substrate molecule to change to the ____________ state
Transition
59
Module 3 (Enzymes Quiz) - What shape is the active site of the enzyme?
3D shape
60
Module 3 (Enzymes Quiz) - Enzyme catalysed reactions are grouped into:
Metabolic pathways
61
Module 3 (Enzymes Quiz) - What is the 'cofactor' that many enzymes require to aid their function?
Metals or vitamins
62
Module 3 (Enzymes Quiz) - Enzymes ma act to lower the activation energy of a reaction by way of:
a. providing an amino acid which briefly participates in the reaction
b. providing a template on which the substrates can more efficiently come together
c. providing a microclimate which is more conducive for the reaction to occur
d. all of the above
d. All of the above
63
Module 3 (Enzymes Quiz) - Metabolic control in a cell can be achieved :
a. by separating groups of enzymes into compartments
b. through structural mechanisms such as grouping enzymes into multi-enzyme assemblies
c. at the level of individual enzymes
d. all of the above
d. All of the above
64
Module 3 (Enzymes Quiz) - Which if the following IS NOT a factor on which the rate of an enzyme-catalysed reaction may depend:
a. amount of substrate
b. amount of inhibitor compounds if they are present
c. the time of day
d. amount of enzyme
c. The time of day
65
Module 3 (Enzymes Quiz) - Feedback inhibition may occur when the end product of a metabolic pathway binds to an enzyme which reacts ________ that pathway
Early in
66
Module 3 (Enzymes Quiz) - The rate of the enzyme catalysed reaction is related to the amount of enzyme and also to
The amount of substrate
67
Module 3 (Enzymes) - What do enzymes do?
They are biological catalysts (mostly proteins) and speed up metabolic reactions by lowering energy barriers.
They are not consumed in a reaction but can speed up a reaction.
68
Module 3 (Enzymes) - All chemical reactions have to have an ______ that can speed up that reaction (ie catalase for Hydrogen Peroxide).
Enzyme
69
Module 3 (Enzymes) - What are the two types of inhibition?
i) Competitive - Blocking the active site of the enzyme
| ii) Allosteric - changing the shape
70
Module 4 - What understanding do genetics provide us with?
How traits are passed down from generation to generation.
71
Module 4 - What are the two critical processes of the cell cycle?
i) Replications of cells genetic material
| ii) Cellular division
72
Module 4 - What is the process of cellular replication called?
Mitosis
73
Module 4 - What are the two major classes of cellular reproduction?
i) Asexual reproduction - Results in cells identical to the parent cells
ii) Sexual reproduction - Results in mixing of the genetic material and thus cells that differ from the parent cells
74
Module 4 - The cell cycle allows _____ organisms (e.g. bacteria) to divide and reproduce and allows ______ organisms to grow and develop from fertilized eggs.
The cell cycle allows unicellular organisms (e.g. bacteria) to divide and reproduce and allows multicellular organisms to grow and develop from fertilized eggs.
75
Module 4 - In eukaryotes, which have very large genomes, the genetic material (DNA) is packaged in linear chromosomes which allows easier replication and distribution. Each chromosome is made up of chromatin.
What is chromatin?
DNA + protein
76
Module 4 - What is the difference between somatic cells and gametes?
i) Somatic cells are the normal cells of the body. In humans, somatic cells have 46 chromosomes.
ii) Gametes are the reproductive cells (sperm and egg cells). They have 23 chromosomes.
When sexual reproduction occurs, and two gametes (sperm and egg) fuse, the number of chromosome is restored to 46.
77
Module 4 - The cell cycle incorporates stages for both _____ growth and ______.
The cell cycle incorporates stages for both cellular growth and replication.
78
Module 4 - What are the 5 distinct stages of mitosis?
i) Prophase
ii) Prometaphase
iii) Metaphase
iv) Anaphase
v) Telophase / cytokinesis
79
Module 4 - Explain prophase
Step 1 - In the nucleus, chromatin fibres condense so chromosomes become visible, consisting of identical sister chromatids joined at the centromere.
The mytotic spindle begins to form in the cytoplasm and centrosomes begin to move apart to either end of the cell.
80
Module 4 - Explain Prometaphase
Step 2 - The nuclear envelope begins to disintegrate, allowing microtubules to attach at the kinetochore.
The spindle extend from each polar centrosome towards the cells equator. Not all spindle fibres attach to chromosomes however.
81
Module 4 - Explain metaphase
Step 3 - Chromosomes move towards the centre of the cell and centromeres of all chromosomes line up equidistant from either pole.
82
Module 4 - Explain anaphase
Step 4 - Paired sister chromosomes split apart to allow individual chromosomes to move to opposite ends of the cell, ensuring that each new cell later ends up with one copy of the duplicated chromosome.
Chromosomes dragged apart by kinetochore microtubules. Poles of the cell move further apart, making cell oval shaped.
83
Module 4 - Explain Telophase / cytokinesis
Step 5 - Cell further elongates. Daughter nuclei begin to form at the two poles. Nuclear membranes begin to form around the chromosomes. Nucleoli reappear. Chromosomes become less condensed and harder to see. Cell cleaves into two daughter parts (cytokinesis).
84
Module 4 - What are the 3 important ways that meiosis allows genetic variation to be produced?
i) Independent assortment of chromosomes
ii) Crossing over (homologuous recombination)
iii) Random fertilisation
85
Module 4 - What is the difference between meiosis and mitosis?
i) meiosis: Involves the division of sex cells
| ii) mitosis: Involves the division of body cells
86
Module 4 - What is S-phase?
The phase of the cell cycle in which DNA is replicated
87
Module 4 - What is interphase?
Refers to all stages of the cell cycle that is not mitosis (about 90% of the cycle time). It is not accompanied by observable changes under the microscope.
During interphase the cell grows, replicates its DNA and prepares for mitosis, during the 3 sub-components:
G1) Cell growth occurs. DNA synthesis occurs.
G2) Cell growth continues. Cell prepares to divide.
Mitotic phase) Short part of the cycle whereby the cell actually divides.q
88
Module 4 - As a result of mitosis, cells divide and two identical daughter cells are produced, a process that is thought to have evolved from simple bacterial _____ _____
As a result of mitosis, cells divide and two identical daughter cells are produced, a process that is thought to have evolved from simple bacterial binary fission.
89
Module 4 - Meiosis involves one round of _____ _______ followed by two rounds of ______ (meiosis I and meiosis II). This results in the production of four ______cells
Meiosis involves one round of DNA replication followed by two rounds of division (meiosis I and meiosis II). This results in the production of four daughter cells
90
Module 4 - How can cellular reproduction occur?
```
By asexual or sexual means.
Asexual process (binary fission in bacteria and mitosis in eukaryotes) allows cells to produce identical daughter cells.
Sexual process (meiosis) allows genes to be mixed both during gamete formation and as a result of random fertilisation.
```
91
Module 4 - What is the location of a gene on a chromosome called?
Locus
92
Module 4 - What is Mendels 1st Law of Segregation?
When pairs of alleles segregate during the formation of gametes (meiosis) and the pairing is
restored by the fusion of gametes during fertilization.
93
Module 4 - What is the difference between a test cross and a back cross?
Testcross: A cross between an unknown genotype and a true breeding recessive phenotype (e.g P? ×
pp). Although the genotype of one parent is not certain (? could be either P or p), the phenotype is purple. A testcross ‘tests’ what the unknown genotype is.
Backcross: crossing F1 offspring to one or other parent
94
Module 4 - What is a monohybrid cross?
Results in the 3 in 4 result where 2 true breeding parents.
95
Module 4 - What is Mendels 2nd Law of Independent Assortment?
Pairs of alleles at different loci segregate into gametes independently
96
Module 4 - What is incomplete dominance?
Dominant genes may not be fully dominant resulting in heterozygote that is intermediate between the two homozygotes
97
Module 4- Chromosomes of the same type and numbers in both sexes are called:
Autosomes
98
Module 4- Genes on a particular chromosome may be split apart by _______ breaking and rejoining during meiosis I. Thus meiosis may give rise to new combinations of genes in gametes.
Genes on a particular chromosome may be split apart by chromatid breaking and rejoining during meiosis I. Thus meiosis may give rise to new combinations of genes in gametes.
99
Module 4 - The further two genes are apart on a chromosome, the ______ likely they are to split during Meiosis I
more likely
100
Module 4 - What kind of fashion are genes organised in along chromosomes?
Linear
101
Module 4 - What does DNA consist of?
Deoxyribose (sugar), a phosphate and one of four bases (A, T, G or C).
102
Module 3 (Quiz) - The process of respiration consumes oxygen and releases the energy from ______________, converting them ultimately back to carbon dioxide and water.
Organic molecules
103
Module 3 (Quiz) - What is metabolic energy ultimately released as?
Heat
104
Module 3 (Quiz) - Electrons transferred through the process of respiration are eventually donated to oxygen, resulting in its reduction to form:
Water
105
Module 3 (Quiz) - Metabolism is basically a collection of simple chemical reactions, each _________ by an enzyme.
Catalysed
106
Module 3 (Quiz) - True or false: The Calvin Cycle is a main stage in respiration
False (photosynthesis)
107
Module 3 (Quiz) - Glycolosis may occur in the first part of the fermentation of ________ by yeasts to lactate (where there is an absence of oxygen)
Ethanol
108
Module 3 (Quiz) - What happens to electrons when oxidation occurs?
They are lost
109
Module 3 (Quiz) - What kind of energy provides life to organisms?
Free energy
110
Module 3 (Quiz) - When matter is recycled through a system, there is also a flow of:
a) Electrons
b) Energy
Energy
111
Module 3 (Quiz) - What is acetaldehyde?
An intermediate compound formed during the process of ethanol fermentation
112
Module 3 (Quiz) - What is the final electron acceptor of the TCA (The Citric Acid) cycle?
Oxygen
113
Module 3 (Quiz) - In each turn of TCA cycle, how many molecules the following are regenerated:
i) ATP
ii) NADH
iii) FADH2
i) 1
ii) 3
iii) 1
114
Module 3 (Quiz) - Which 2-carbon molecule enters the TCA cycle?
Acetyl CoA
115
Module 3 (Quiz) - What do the NADH and FADH2 produced during the TCA cycle do?
Transport electrons
116
Module 3 (Quiz) - The final electron transport chain in the process of respiration consists of a series of proteins located:
In the inner mitochondrial membrane
117
Module 3 (Quiz) - The final stage of respiration is the process of ATP synthesis by what?
Oxidative Phosphorlyation
118
Module 3 (Quiz) - What is the name of the membrane protein that allows protons to flow back into the mitochondrial matrix?
ATP synthase
119
Module 3 (Quiz) - What does potential energy do at the end of respiration?
It is an electrochemical gradient that fuels the activity of ATP synthase protein
120
Module 3 (Quiz) - Why is the electrochemical gradient that moves across the mitochondrial membrane called as such?
Because +ve charges are moved, and the chemical H is also moved
121
Module 3 (Quiz) - How many ATP molecules may be produced during oxidative phosphorylation:
26-28
122
Module 3 (Quiz) - What is the role of the electron transport chain in the mitochondrial membrane?
to set up an electrochemical gradient across the mitochondrial membrane
123
Module 3 (Quiz) - Most of the carbon dioxide we breathe out has been produced by the conversion of:
pyruvate to acetyl CoA
124
Module 3 (Quiz - photosynthesis) - What groups are included as photoautotrophs?
Plants, algae and some prokaryotes
125
Module 3 (Quiz - photosynthesis) - What do chemoautotrophs provide through the oxidisation of inorganic chemicals?
Energy
126
Module 3 (Quiz - photosynthesis) - Name 3 structural components of a chloroplast
i) Stroma
ii) Thylakoid
iii) Grana
127
Module 3 (Quiz - photosynthesis) - What chemical energy do the light reactions of photosynthesis convert solar energy to?
ATP and NADH
128
Module 3 (Quiz - photosynthesis) - To convert CO2 to organic compounds (sugars, what does the Calvin Cycle use?
ATP and NADH
129
Module 3 (Quiz - photosynthesis) - What photosynthetic pigments capture light energy?
i) Chlorophyll a
ii) Chlorophyll b
iii) Carotenids
130
Module 3 (Quiz - photosynthesis) - What colour light do photosynthetic pigments not absorb?
Green
131
Module 3 (Quiz - photosynthesis) - Where are light harvesting pigment complexes located?
Thylakoid membrane of chloroplasts
132
Module 3 (Quiz - photosynthesis) - Noncyclic and cyclic electron flow are the two types of electron flow in what kind of reaction?
Light
133
Module 3 (Quiz - photosynthesis) - Which of the following IS NOT a phase of the Calvin cycle:
a. oxidative phosphorylation
b. reduction
c. regeneration of a CO2 acceptor
d. carbon fixation
a. oxidative phosphorylation (respiratory)
134
Module 3 (Quiz - photosynthesis) - What is the final product of the Calvin cycle?
glyceraldehyde 3 phosphate
135
Module 4 (Quiz - Genetics) - The ‘cell cycle’ involves two critical processes - the replication of cells genetic material followed by:
Select one:
a. cellular division
b. cellular fusion
c. apomixis
d. cell expansion
cellular division
136
Module 4 (Quiz - Genetics) - RNA is read three bases at a time - the three bases read each time being called a:
Select one:
a. tryptich
b. nucleotide
c. codon
d. centriole
codon
137
Module 4 (Quiz - Genetics) - DNA is made up of a series of bases strung along a sugar and _________ backbone.
Select one:
a. nitrate
b. calcium
c. potassium
d. phosphate
phosphate
138
Module 4 (Quiz - Genetics) - The 'lagging' strand of DNA is initially made as a series of small pieces called ____________ which are later joined up by an enzyme called DNA ligase.
Select one:
a. takoyaki fragments
b. origami fragments
c. suzuki fragments
d. okazaki fragments
okazaki fragments
139
Module 4 (Quiz - Genetics) - Some tRNAs recognise more than one codon -this is known as the :
Select one:
a. null hypothesis
b. wobble hypothesis
c. excess RNA hypothesis
d. evolutionary hypothesis
wobble hypothesis
140
Module 4 (Quiz - Genetics) - In eukaryotes, the mRNA must first be transferred from the nucleus to the cytoplasm before _____________ can read and translate it.
Select one:
a. nucleoli
b. ribosomes
c. golgi
d. spindles
ribosomes
141
Module 4 (Quiz - Genetics) - Genes on a particular chromosome may be split apart by chromatid breaking and rejoining during:
Select one:
a. prophase 2
b. interphase
c. anaphase I
d. meiosis I
meiosis I
142
Module 4 (Quiz - Genetics) - In humans, there are 22 pairs of:
Select one:
a. Y chromosomes
b. autosomes
c. sex chromosomes
d. none of the above
autosomes
143
Module 4 (Quiz - Genetics) - The basic laws of genetics were first discovered by Gregor Mendel by studying the inheritance of simple traits in:
Select one:
a. Drosophila
b. corn
c. peas
d. humans
peas
144
Module 4 (Quiz - Genetics) - Unlike simple dominance, the phenotype of the heterozygote may be intermediate between the two homozygotes and this is called:
Select one:
a. epistasis
b. pleiotrophy
c. a testcross
d. incomplete dominance
incomplete dominance
145
Module 4 (Quiz - Genetics) - What is the probability of a heterozygous organism with alleles for a gene Aa passing on the A allele?
Select one:
a. 0.5
b. 0.25
c. 1.0
d. none of the above
0.5
146
Module 4 (Quiz - Genetics) - Pairs of alleles segregate during the formation of gametes (meiosis) and the pairing is restored by the fusion of gametes during fertilization. This is known as:
Select one:
a. Mendel's first law
b. Mendel's second law
c. Chargaff's rule
d. Morgan's law
Mendel's First Law
147
Module 4 (Quiz - Genetics) - Chromosomes move toward the centre of the cell and centromeres of all chromosomes line up equidistant from either pole during which mitotic phase:
Select one:
a. prophase
b. metaphase
c. anphase
d. telophase
metaphase
148
Module 4 (Quiz - Genetics) - In _______________ organisms, cell division may allow replacement of damaged or dead cells.
Select one:
a. extinct
b. unicellular
c. multicellular
d. amoeboid
multicellular
149
Alternative versions of genes are called:
Select one:
a. chromatids
b. alleles
c. heterozygotes
d. codominant
Alleles
