Unit 3-4 Flashcards
(108 cards)
1
Q
An organism with two identical alleles for a trait is said to be _____________ for the trait.
A
homozygous
2
Q
Differentiate a gene from an allele.
A
allele is a variation of a gene
3
Q
Which of the following is not a condition for a population to be Hardy-Weinberg equilibrium?
A
The population is infinitely small
4
Q
A person who is heterozygous for a recessive genetic disease, such as Tay-Sachs, is said to be
A
carrier
5
Q
A dihybrid cross involving two traits at the same time will typically produce which of the following phenotypic ratios in the F₂ generation?
A
9:3:3:1
6
Q
The _________ of an organism can be homozygous or heterozygous.
A
genotype
7
Q
Mendel started with ____________ crosses and studied F₁ and F₂ generation of these crosses. Based on his results, Mendel designated alleles as either dominant alleles or recessive alleles.
A
monohybrid
8
Q
Codominance
A
The allele that is present will be expressed irrespective of the other alleles.
9
Q
Polygenic inheritance
A
traits resulting from the combined additive effects of multiple genes with multiple genes with multiple alleles. Ex height
10
Q
Hybrid vigor
A
The phenomenon of hybrids between inbred homozygous strains being more robust and productive than either parent is commonly called hybrid vigor or heterosis
11
Q
Genotype
A
The genetic makeup of an organism
12
Q
Phenotype
A
the physical makeup of an organism that specific alleles of genes influence
Phenotype ratio for dominant and recessive traits: 9:3:3:1
13
Q
If an organism is diploid and has 64 chromosomes, how many chromosomes will its gametes have?
A
32
14
Q
In a diploid organism with 56 chromosomes, what term describes a cell that has 55 chromosomes?
A
monosomy
15
Q
A female carrier of an X-linked recessive trait plans to have a child with an affected male. What is the probability that a male child will have the trait?
A
50%
16
Q
___________, such as human body cells, contain two sets of chromosomes (2n)
A
Diploid cells
17
Q
_________, such as gametes, contain one set of chromosomes (n).
A
Haploid cells
18
Q
During prophase I of meiosis, homologous chromosomes align and exchange genetic information, a process called
A
crossing over
19
Q
All chromosomes, other than the sex chromosomes, are ____________ chromosomes
A
autosomal chromosomes.
20
Q
involves genes that are located on the sex chromosomes.
A
sex-linked inheritance
21
Q
Pedigree:
A
A genealogical chart that identifies individuals with a specific trait.
22
Q
Nondisjunction
A
The erroneous movement of two homologous chromosomes to the same pole during meiosis, resulting in one gamete with two homologues and one gamete with none.
23
Q
Karyotype
A
A picture of a cell’s complete set of chromosomes that are organized by size.
24
Q
Autosomal recessive trait
A
a genetic condition occurs when the child inherits one mutated copy of a gene from each parent. The parents usually do not have the condition. The parents are called carriers because they each carry one copy of the mutated gene and can pass it to their children.
25
Autosomal dominant trait
a way a genetic trait or condition can be passed down from parent to child. One copy of a mutated (changed) gene from one parent can cause the genetic condition. A child who has a parent with the mutated gene has a 50% chance of inheriting that mutated gene.
26
Sex-linked recessive trait:
A female carrying a mutation in one gene, with a normal gene on the other X chromosome, is generally unaffected
27
The transfer of information from DNA to RNA is called
transcription
27
Meiosis
a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores.
27
Where does RNA polymerase bind?
the promoter
28
Which of these is not a component of RNA?
Thymine
29
Which of these RNA modifications occurs last?
A poly-A tail is added to the end of the RNA strand.
30
What is the function of a chaperonin?
to guide the folding of a polypeptide molecule
31
The lac operon is an example of __________ in prokaryotes.
gene regulation
32
Three RNA types are involved in protein synthesis
mRNA,tRNA,rRNA
33
During _______________, the double helix is unwound, and RNA polymerase adds complementary nucleotides to the DNA template strand to form RNA.
transcription
34
_________ are removed from the transcript, and__________ are spliced together.
Introns ,exons
35
The ___________is the set of rules that determine which mRNA codons code for which amino acids.
genetic code
36
Translation:
the process of translating the sequence of a messenger RNA (mRNA) molecule to a sequence of amino acids during protein synthesis.
37
Anticodon:
a three-nucleotide sequence on a tRNA molecule that is complementary to the codon
38
Biotechnology
The use of living organisms and biological processes to meet human needs and wants.
39
Restriction enzymes
an enzyme, usually produced by bacteria, that can cut a DNA strand at a specific sequence of nucleotide base pair.
40
Polymerase chain reaction
A technology that allows scientists to make many copies of DNA sequences.
41
Recombinant DNA
A sequence of DNA that has been artificially formed by combining DNA from two different organisms.
42
Genetically modified organisms
an organism that expresses a trait acquired through genetic engineering.
43
DNA fingerprinting:
A method of comparing DNA from individuals to an unknown DNA sample by looking for sequences unique to that individual.
44
1. How many parts does a scientific name have?
two
45
Which of the following lists the taxa from the most specific to the most general?
species, genus, family, order, class, phylum, kingdom
46
Which word describes a group of organisms and their most recent common ancestor?
monophyletic clade
47
What are the three domains?
Bacteria, Archaea, Eukarya
48
Head shape is which type of character?
morphological
49
__________________ is the process of placing living things into groupings according to the characteristics they share.
Classification
50
_____________ is the system of naming and classifying organisms based on shared characteristics and a universal set of rules.
Taxonomy
51
_____________ are groups into which organisms with shared characteristics are organized. The most specific taxon is the species.
Taxa (singular taxon)
52
According to the ____________ concept, a species is a group of organisms of the same type that can interbreed to produce fertile offspring.
biological species
53
Linnaeus developed binomial nomenclature. The levels of this classification system are: species, genus, family, order, class, phylum, and kingdom.
binomial nomenclature
54
____________characters are unique characteristics differing from the ancestral ones that originate in a clade.
Derived
55
Taxonomy
The science of classifying living things
56
Taxa
a group into which organisms with shared characteristics are organized.
57
Characters:
inherited traits shared by a group of organisms.
58
Clade
a group of organisms believed to have evolved from a common ancestor.
59
Derived characteristics:
a more recent, unique character that originates in a clade.
60
Ancestral characteristics:
a relative term describing a trait that is considered to be older than the derived trait.
61
Monophyletic trait
groups of organisms, including their most recent common ancestor and the descendants of that most recent common ancestor.
62
Polyphyletic clade
a group of organisms that is not monophyletic and does not include the most recent common ancestor, usually because the common ancestor does not have the same characteristics as the group.
63
Homoplasy
similarities in organisms that are not due to common ancestry, but rather due to similar adaptations to environmental pressures.
64
Which of the following structures is found in viruses?
a protein coat
65
During times of environmental stress, bacteria may form
endospores.
66
Prokaryotes include
archaea and bacteria.
67
Which structures are used by paramecium for movement and feeding?
pseudopodia
68
Kelp belong to which kingdom?
Protista
69
_________ are nonliving particles that infect cells by inserting their genetic material into the host cell.
Viruses
70
___________ can be helical, polyhedral, spherical, or complex. All viruses are made of either DNA or RNA surrounded by a protein coat.
Viruses
71
Viruses are often _________ and cause disease in other organisms, including humans, plants, and bacteria.
pathogens
72
Viruses may replicate through either the ___________ ________, or the lysogenic cycle.
lytic cycle
73
Retroviruses must convert their RNA to DNA using _______________ before the DNA can be incorporated into the host cell’s genome.
reverse transcriptase
74
____________ are simple, unicellular organisms that lack a nucleus
Prokaryotes
74
____________ have close relationships with many other organisms. They form symbiotic partnerships, take part in food webs, and act as decomposers. Some protists cause diseases in humans and other organisms
Protists
74
Pathogens:
an organism, virus, or infectious protein that causes diseases or illness in another organism.
75
Lytic cycle
a form of viral replication in which many copies of viruses are made within the host cell, causing the cell to burst.
76
Lysogenic cycle
a form of viral replication in which the viral genes are added to and copied along with the host cell genome without destroying the host cell.
77
Endospores
: a protective, dormant cell formed by bacteria during environmental stress.
78
Flagella
A long whip-like structure found in some cells that facilitate movement.
79
Conjugation
the exchange of genetic material between two bacterial cells.
80
Algae:
plant-like protists that make their own food through photosynthesis.
81
Chitin
a tough yet flexible carbohydrate found in the cell walls of fungi and in the exoskeleton of some arthropods.
82
Mycorrhizae
a mutualistic relationship between fungi and plant roots.
83
. Which of these is only found in angiosperms?
A. vascular bundles
B. seeds
C. gametophytes
D. fruits
fruits
84
What is transpiration?
A. the loss of water through stomata
B. the movement of sugar through phloem
C. the absorption of water through root hairs
D. an area of elongation at the tips of stems
the loss of water through stomata
85
Which of these is not a function of auxin?
A. maintains apical dominance
B. ripens fruit
C. prevents leaves from falling
D. inhibits branch formation
maintains apical dominance
86
Which of the following plant parts is composed of ground tissue?
A. cuticle
B. xylem
C. pith
D. palisade mesophyll
xylem
87
What process results in the formation of endosperm?
A. alternation of generations
B. double fertilization
C. germination
D. gravitropism
double fertilization
88
1. What distinguishes invertebrates from other animals?
A. They can reproduce asexually.
B. They do not have a backbone.
C. They have jointed appendages.
D. They have bilateral symmetry
They do not have a backbone.
89
What characteristic do sponges share with mollusks and arthropods?
A. They exchange matter with the environment.
B. They have an open circulatory system.
C. They only live in aquatic habitats.
D. They have a coelom.
They exchange matter with the environment.
90
Which characteristic is true of cnidarians but not ctenophores?
A. They have a gastrovascular cavity.
B. Their life cycle has both polyp and medusa stages.
C. They have a nerve net.
D. They develop from two germ layers.
Their life cycle has both polyp and medusa stages.
91
Which characteristic distinguishes annelid body plans from roundworms?
A. a tough exoskeleton
B. segmentation
C. a gastrovascular cavity
segmentation
92
Which organisms have radial symmetry?
A. cnidarians and echinoderms
B. arthropods and annelids
C. rotifers and mollusks
D. mollusks and echinoderms
cnidarians and echinoderms
93
Which group of invertebrates is the most numerous on Earth?
A. cnidarians
B. echinoderms
C. arthropods
arthropods
94
. Which organisms infect humans as parasites?
A. echinoderms
B. cnidarians
C. porifera
D. roundworms
roundworms
95
Vertebrates differ from invertebrates because vertebrates have
A. muscles and nerves.
B. a bony internal skeleton.
C. wings and legs.
a bony internal skeleton.
96
Goldfish differ from sharks because goldfish have
A. a bony skeleton.
B. paired fins.
C. gills.
D. a complete digestive system.
a bony skeleton.
97
Which is true of all amphibians?
A. They have a tadpole stage.
B. They have four legs.
C. They have a two-chambered heart.
D. They have soft, moist skin.
They have soft, moist skin.
98
Which of the following is not a strategy reptiles use to regulate temperature homeostasis?
A. behavioral thermoregulation
B. endothermy
C. ectothermy
D. hibernation
endothermy
99
Mammals are the only kind of animals
that have
A. live birth.
B. mammary glands.
C. teeth.
D. a single bone that attaches the leg
to the body.
mammary glands.
100
. Which of these describes a trace fossil?
A. a space left in sedimentary rock after an organism is buried
B. a two-dimensional flattened outline within a rock layer
C. the fossilized shell of a marine invertebrate
D. serrated bite marks on a bone
a two-dimensional flattened outline within a rock layer
101
How might an entire organism become fossilized?
A. The hard parts of an organism deteriorate slowly.
B. An organism becomes trapped in amber.
C. A cast forms when a mold fills with calcium carbonate.
D. A burrow of an animal is visible within rock layers
An organism becomes trapped in amber.
102
The abrupt appearance of many different organisms in the fossil record is an example of
A. stasis.
B. mass extinction.
C. radiation.
D. coprolites.
mass extinction.
103
In the fossil record, scientists observe that species increase in number, but phyla decrease. This is an example of which pattern in the fossil record?
A. species increase while higher taxa decrease
B. stasis
C. less familiar to more familiar
D. marine to land
a. species increase while higher taxa decrease
104
Which of the following supports the idea that fossils formed millions of years in the past?
A. the presence of macromolecules in fossilized bone
B. radiometric dating of surrounding rock layers
C. rapid burial of organisms
D. mass extinction events
radiometric dating of surrounding rock layers
