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a3.1 (diversity of organisms) Flashcards

1
Q

define organism

A

An organism is any biological system that functions as an individual life form. All organisms are composed of cells.

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2
Q

define population

A

A population is a group of organisms of the same species in the same area (C4.1.1). Even though they are the same species, the individual organisms of the population vary from each other.

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3
Q

define community

A

Communities are the populations of two or more different species occupying the same geographical area at the same time (C4.1.10) . There is great variation between different species.

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4
Q

define variation

A

Variation is a defining feature of life. Variation refers to differences between members of a group. Variation can be discrete or continuous.

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5
Q

define discrete variation

A

traits that can be put into distinct qualitative categories

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6
Q

what is discrete variation caused by?

A

usually influenced by only one or a few genes. They can also be influenced by environment, although usually not significantly (it is a one or the other deal)

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7
Q

examples of discrete variation (name a few)

A

lefty/righty, petal colour in a flower, blood type

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8
Q

define continuous variation

A

traits that vary along a quantitative continuum. Most types of biological variation are continuous.

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9
Q

what is continuous variation caused by?

A

result from complex interaction between many different genes (“polygenic”), often with the environment playing a significant part in the expression of the phenotype (D3.2.14).

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10
Q

examples of continuous variation (name a few)

A

height, body mass, milk yield of cow, root length of plant, skin colour

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11
Q

examples of variation at different levels of biological variation x4

A

molecular, such as between genomes (A3.1.19)

cellular, such as between specialized cells in multicellular organisms (A2.2.13)

organisms, such as in the speed of nerve impulses (C2.2.4)

ecosystems, such as between biomes (B4.1.7).

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12
Q

define intraspecies variation & provide an example

A

inheritable variation within a species (giraffe spots, eye colour, hair colour)

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13
Q

4 different ways for intraspecies variation to be observed

A

Mutation: the changes in the sequences of genes in DNA (D1.3.7)

Gene flow: the movement of genes between different populations of organisms (D4.1.9*)

Meiosis: formation of egg and sperm which leads to the creation of new combinations of alleles (D2.1.11)

Sexual reproduction: random fertilization between egg and sperm (D3.1.2)

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14
Q

what is the main driver of evolution

A

natural selection

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15
Q

what does the amount of variation between individual organisms depend on?

A

how closely related they are

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16
Q

order of classification of organisms (least to most specific) x8

A

domains, kingdom, phylum, class, order, family, genus, species (and breeds, not very significant)

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17
Q

define species

A

groups of living things recognizably distinct from all others by their shared characteristics

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18
Q

how to denote a species

A

the first term indicates the genus
the second term indicates the specific species

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19
Q

4 rules for binomial nomenclature (naming)

A

the genus name begins with a capital letter

the species name begins with a lowercase letter

in print, the name is in italics (underline if handwritten)

after one use in a text, Genus name can be abbreviated to the first letter (i.e. H. sapiens)

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20
Q

two benefits of binomial nomenclature

A

Reflects evolutionary relationships between organisms AND Enables scientists to talk to each other in the same language

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21
Q

define species according to the biological species concept

A

a group of organisms that can breed and produce fertile offspring.

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22
Q

why can’t hybrid species reproduce?

A

because they have an odd # of chromosomes

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23
Q

examples of hybrid species (name a few)

A

mules, liger, coywolf, narluga, sheep-goat

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24
Q

how do hybrid species arise?

A

Occurs when two different species can reproduce to create offspring.

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25
how do starfish asexually reproduce?
through regeneration (In binary fission, the parent organism's cell divides exactly into two genetically identical daughter cells. During the process, the central discs present in the mature starfish break into two pieces.)
26
when does genetic mosaicism occur?
the presence of two or more cell lineages with different genotypes arising from a single zygote in a single individual (when a multicellular organism contains more than one genetic line as a result of mutation)
27
how does speciation occur?
If two populations of the same species do not interbreed, physical and/or behavioural differences may accumulate and they can diverge to the point of becoming separate species
28
what is a result of the slow and gradual divergence during speciation?
a grey zone where the periods of time between there clearly being 1 species and there clearly being two resulting species, difficult to distinguish between the two
29
diploid cell main characteristic
2 copies of every chromosome organized in homologous pairs (46 chromosomes) (most cells)
30
haploid cells are seen in humans as _____
gametes/sex cells (23 chromosomes)
31
what animals are exceptions to most animal adult cells being diploids and sex cells being haploids?
adult male bee, wasp and ant cells are haploid
32
exceptions to haploids = n AND diploids = 2n for individual species (name a few)
chromosomal disorders, cells without a nucleus OR with multiple nucleui, gametes, polyploids (species containing more than two sets of chromosomes)
33
define karyogram
a representation of chromosomes found in a cell
34
how are chromosomes arranged in karyograms?
the chromosomes are arranged by size and shape (position of centromere)
35
define karyotype
the number and appearance of chromosomes specific to a person
36
banding on chromosomes indicate a stronger presence of what?
A-T bonding
37
5 steps to creating a karyogram
Cells are stained and prepared on a glass slide to observe chromosomes with light microscope. Photomicrograph images obtained during the mitotic metaphase (second) (why? = so they are still attached). Images of chromosomes are cut out and separated (manually or via computer). Images of chromosomes are arranged in pairs and placed in order by size and centromere position. Band positioning on chromosomes helps to identify pairs.
38
define genome
the complete set of genetic material found in an organism
39
define gene
a distinct sequence of nucleotides as part of a chromosome, giving rise to a protein product
40
define allele
one of two or more alternate forms of a gene that arise by mutation and are found on the same place on a chromosome
41
humans share the same _____ (unity) but have different versions of these _____ (diversity) called _____
genes, genes, alleles
42
alleles can be ___________ or ___________
heterozygous (Aa) OR homozygous (AA, aa)
43
which blood types have which ABO glycoproteins? are they homo/heterozygous? x4
type a (AA, AO) (has type A glycoproteins) type b (BB, BO) (has type B glycoproteins) type ab (AB) (has type A&B glycoproteins) type o (OO) (doesn't have A or B glycoproteins)
44
what is SNPs? (function and acronym)
single nucleotide polymorphisms (SNPs) are variations at a single position in a DNA sequence among individuals. they are the most common type of genetic variation
45
when do SNPs occur?
when a single nucleotide (A, T, C, or G) in the genome differs between members of a species
46
what can SNPs influence?
how individuals respond to drugs, susceptibility to diseases, and other traits
47
what are SNPs useful for? x2
studying genetic associations AND for personalized medicine
48
what ~percentage of SNPs are functional? what are the rest?
5, the remainder are neutral & do not affect the phenotype
49
genotype VS phenotype
genotype: genetic sequence phenotype: gene expression
50
what was the human genome project? what was its aim?
an international research initiative completed in 2003 that aimed to map and sequence the entire human genome
51
what did the human genome project accomplish?
it identified and cataloged all the genes in human DNA, providing a comprehensive blueprint of human genetic makeup
52
what did the human genome project determine about human gene count?
humans have about 22000 genes
53
how many eukaryotic species are there on our planet? give or take what>
8.7 million, give or take 1.3 million
54
what are pseudogenes?
considered to be evolutionary “leftovers” of once functional genes that have acquired too many insertions or deletions
55
why do we have pseudogenes? what benefit does it serve?
because it shows a history of our evolution overtime, it can also be a sort of protective factor to the functional genes.
56
why is protein sampling often done from mitochondria DNA?
because it works well and is essential, so it is very stable and will not change its function (some mDNA is a part of the electron transport chain in the generation of ATP)
57
define phylogenetics
the comparison of whole genomes to determine relatedness
58
define sanger sequencing
a technique developed by Frederick Sanger in 1977 for determining the nucleotide sequence of DNA
59
6 steps of sanger sequencing
DNA Fragmentation Preparation of Reaction Mixtures Extension and Termination Separation of Fragments Detection and Sequencing Sequence Assembly
60
define next generation sequencing
a set of advanced technologies that allow for rapid and cost-effective sequencing of large amounts of DNA or RNA
61
differences between next generation sequencing and sanger sequencing
Unlike traditional Sanger sequencing, which sequences one DNA fragment at a time, NGS can sequence millions of fragments simultaneously
62
biological species concept does not work well with what groups of organisms? x3
reproduce asexually (i.e. bacteria) form populations of related, but genetically isolated clones (i.e dandelions) acquire genes from other groups without reproduction (i.e. bacteria)
63
define asexual reproduction
occurs when a single parent passes on its full set of genes to offspring, resulting in genetically identical offspring
64
how are asexually reproducing organisms classified as a species?
based on appearance or biochemical similarities
65
define apomixis, what species reproduce in this way?
some species of plants that produce flowers but do not require fertilization of gametes to produce seeds. instead, seeds are asexually produced by mitosis and the seedlings that germinate are genetically identical clones of the parent plant
66
define horizontal gene transfer
the movement of DNA between individuals through mechanisms that are not the normal movement of DNA from parent to offspring (often thru a virus)
67
what is horizontal gene transfer frequent among?
bacteria
68
define conjugation
a process that involves the transfer of DNA via a plasmid from one bacteria to another during cell-to-cell contact
69
when is cross-breeding between closely related species unlikely to result in fertile offspring?
if parent chromosome numbers are different
70
define DNA barcoding
a technique used to identify and classify organisms based on a short, standardized region of their DNA
71
define dichotomous key
a tool used to identify a species based on observable traits, where each step gives two distinct choices that will lead users to the correct identification
72
5 steps to DNA barcoding
1. Selection of a barcode region 2. DNA extraction 3. Amplification using PCR 4. Sequencing 5. Comparison and identification
73
what purpose do bioindicators/indicator species include?
indicates a lack of that specific pollution and vice versa
74
environmental DNA pros x4
Doesn’t involve capturing species. Single sample used to determine presence of hundreds of organisms. Sequencing is relatively quick. More time efficient than ecological surveying when tracking an environment over time.
75
environmental DNA cons x3

biology hl (20 decks)

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