Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

biology - genetic Info, variation + relationships > key terms > Flashcards

key terms Flashcards

(63 cards)

Start Studying
1
Q

what is an adaptation?

A

a feature of an organism that increases its chances of survival in its environment - anatomical, behavioural or physiological

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is an allele?

A

different versions of a gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is an anticodon?

A

a sequence of three nucleotide bases at one end of a tRNA molecule that is specific to an mRNA codon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is binomial system?

A

universal system of naming organisms that consists of two parts: the Genus and species e.g. Homo sapiens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is biodiversity?

A

the variety of genes, species and habitats within a particular area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is a chromatid?

A

one strand of a replicated chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is a chromosome?

A

consists of long, coiled molecule of DNA and its associated with histone proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is a chromosome mutation?

A

a change to the number or structure of chromosomes that can occur spontaneously

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is classification?

A

the organisation of organisms into groups - artificial and phylogenetic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is artificial classification?

A

type of classification that organises organisms into groups based on analogous characteristics such as leaf shape, number of legs and type of wing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is a codon?

A

a sequence of three bases on mRNA that codes for a specific amino acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is conservation?

A

the maintenance of ecosystems and biodiversity by humans in order to preserve the earths resources

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is courtship behaviour?

A

a set of behaviour exhibited by members of species to attract a mate. It enables organisms to recognise members of their own species, identify a mate that is capable of breeding, form a pair bond and synchronise mating.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is crossing over?

A

process in meiosis 1 in which homologous chromosomes align, their chromatids twist around each other and their alleles are exchanged at the chiasma by putting tension of chromatids, causing them to break and rejoin on the other chromatid. creates genetic variation by creating new combination of alleles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what does degenerate mean?

A

feature of the genetic code
more than one triplet can code for the same amino acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is deletion?

A

a form of gene mutation in which one or more nucleotide bases are removed from a DNA sequence. This changes all codons from this point (frameshift) This may change all amino acids in a sequence causing the protein to be non-functional

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is directional selection?

A

-selects for one of the extremes
- occurs in changing environments
- the modal trait changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is ecosystem diversity?

A

a measure of the range of different habitats in a particular area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is Eukaryotic DNA?

A
  • linear molecules of DNA which together with histones form chromosomes
  • DNA in the mitochondria and chloroplasts of eukaryotic cells is circular and does not have associated proteins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is an exon?

A
  • a sequence of dna that codes for an amino acid sequence
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is fertilisation?

A

the random fusion of haploid gametes during fertilisation to produce a zygote, creating genetic variation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is a gene?

A

a sequence of DNA bases that codes for a polypeptide and functional RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is a gene mutation?

A

a change in the DNA base sequence, occurs spontaneously during DNA replication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is the genetic code?

A

universal, degenerate and non-overlapping

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what is genetic diversity?
The number of different alleles of each gene in a population - investigated by comparing observable characteristics, DNA and mRNA base sequences and amino acid sequences
26
what is the genome?
the entire genetic material of one cell
27
what are histones?
proteins that associate with DNA to form chromosomes in eukaryotic cells
28
what are homologous chromosomes?
A pair of chromosomes that have the same genes in the same location, same size but may have different alleles
29
what is independent segregation?
the random alignment of homologous chromosomes along the equator that creates many possible combinations of maternal and paternal chromosomes (2 to the power of n)
30
what is the index of diversity?
describes the relationship between the number of different species and the number of individuals in each of these species within a community
31
what is an intron?
a non coding sequence of DNA
32
what is a locus?
the fixed position of a gene on a chromosome
33
what is meiosis?
a type of cell division that produces four genetically different daughter cells (gametes) with a haploid number of chromosomes. it involves two nuclei devisions
34
what is mRNA?
a type of RNA that carries genetic information from the nucleus to the ribosomes for protein synthesis. it is a single helix consisting of thousands of nucleotides
35
what is mitosis?
a form of cell division that produces two genetically identical diploid daughter cells
36
what is a mutagenic agent?
an agent that increases the rate of gene mutations e.g. tobacco, alcohol, UV
37
what is natural selection?
the process by which the frequency of advantageous alleles gradually increases in a populations gene pool over time
38
what is a non-coding sequence?
a sequence of DNA that doesn’t code for an amino acid sequence e.g. introns, make up significant portions of eukaryotic DNA
39
what is non-disjunction?
a change in the number of chromosomes due to the failure of homologous chromosomes separating during meiosis. may result in a gamete with one more or one less chromosome
40
what is non-overlapping?
a feature of the genetic code each base in a sequence is read once as a discrete unit, only part of one triplet
41
what is phylogenetic classification?
divides organisms into groups based on evolutionary relationships and origin, uses a hierarchy in which smaller groups are arranged within larger groups with no overlap between groups
42
what is phylogeny?
the evolutionary relationships between individuals or groups of organisms
43
what is prokaryotic DNA?
circular DNA that is not associated with histones
44
what is random sampling?
sampling technique used to avoid bias e.g. using random co-ordinates
45
what are ribosomes?
where protein synthesis takes place, made from rRNA and protein
46
what is RNA polymerase?
an enzyme that moves along the DNA template strand and joins adjacent nucleotides by forming phosphodiester bonds to form pre-mRNA
47
what is a species?
a group of similar organisms that can interbreed to produce fertile offspring
48
what is species diversity?
a measure of the number of different species and the number of individuals in each of these species within a community
49
what is species richness?
A measure of the number of different species within a community at a particular time
50
what is splicing?
removal of introns from pre-mRNA following transcription in eukaryotic cells, to form mRNA
51
what is stabilising selection?
- occurs in unchanging environments - selects for the modal traits - standard deviation decreases
52
what is substitution?
form of gene mutation in which one nucleotide base is exchanged for another. This may change an amino acid or have no effect because the of the degenerate DNA code
53
what is a taxon?
each group within a phylogenetic classification system
54
what is transcription?
the formation of pre-mRNA in eukaryotes and mRNA in prokaryotes from a section of the template strand of DNA
55
what is stabilising selection?
- occurs in unchanging environments - selects for modal traits - standard deviations decrease
56
what is substitution?
a form of gene mutation in which one nucleotide base is exchanged for another. this may have no effect on the amino acid sequence due to DNA code being degenerate
57
what is a taxon?
each group within a phylogenetic classification system
58
what is transcription?
the formation of pre-mRNA in eukaryotes and mRNA in prokaryotes from a section of the template strand of DNA, first stage of protein synthesis
59
what is tRNA?
a form of RNA that carries specific amino acids to the ribosomes. It is single stranded and has a clover-leaf shape, one side is longer than the other to allow the attachment of an amino acid. At the opposite end is an anticodon specific to an amino acid.
60
what is translation?
the second phase of protein synthesis, takes place in the ribosomes. mRNA is used as a template for the attachment of tRNA molecules with complementary anticodons. the amino acids carried on adjacent tRNA molecules are joined to form a polypeptide chain
61
what is a triplet?
sequence of three bases that codes for an amino acid
62
what does universal mean?
feature of the genetic code the same codon codes for the same amino acid in all organisms
63
what is variation?
the differences between individuals due to genes, the environment

biology - genetic Info, variation + relationships (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions