Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology > 4 genetic information, variation and relationships between organisms > Flashcards

4 genetic information, variation and relationships between organisms Flashcards

kms

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

what are the properties of dna in eukaryotes

A

. molecules are longer and linear and histone bound
. dna wound to fit into the nucleus, histones support dna
. dna and histones coil tigjtly to form chromosomes

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

what are the propertiesof dna in prokaryotes

A

. dna molecules are shorter, circular and not histone/protein bound
. (mitochondria and choroplasts in eukaryotes also contain this type of dna)

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

what is a gene

A

. dna contains genes
. gene is a sequence of bases on dna which determine aa sequence of a polypetide
. does this by coding for functional RNA

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

what is a locus

A

. fixed position occupied by a gene ona particular dna molecule

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

whta si an allele

A

. genes exist in different forms
. different versions called alleles
. order of bases in each allele varies so code for different versions of the same polypeptide

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

what is triplet code

A

. a sequence of three dna bases that code for a specific amino acid
. a triplet is known as a codon

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

what is one codon

A

. one amino acid

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

explain the features of teh genetic code

A

. code is universal for all organisms
. non overlapping so each triplet is read separately
. degenerate - some aa have more than one triplet code
.

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

what are genome and proteome

A

. genome - all genes ina cell
. proteome - all proteins that a cell ca produce

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

What are Introns and exons

A

. Exons - sequences within a gene code for amino acid sequences. 
. Intro - non-coding sequences.

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

What are the features of mRNA and T RNA? 

A

. MRNA-single-stranded, linear chain, long chain, corresponds to genetic sequence of a gene, unpaired bases.
. tRNA - single-stranded folded into clover shape, hydrogen bonds, anticodon, amino acid attachment, or similar lengths. 

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

Explain polypeptide synthesis

A

. The sequence of nucleotides on a gene on DNA act as template
. Complementary copies transcribed on mRNA in nucleus.
. Ribosomes, mRNA axis template that is translated into chain of AA using complementary tRNA which carries specific AA which are linked together.

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

What is pre-mRNA and splicing?

A

. Happens in eukaryotic cells only.
. mRNA produced during transcription contains introns and exons (pre-mRNA)
. introns need removing because they don’t contain genetic info that can be translated to aa sequence
. spliced out of mRNA sequence with enzyme
. produces strand of mRNA containing exons only, known as mature mRNA

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

Describe how mRNA is formed by transcription in eukaryotes

A

. Hydrogen bonds between bases broke.
. One DNA strand acts as template.
. RNA nucleotides aligned by complementary base pairing
. Uracil base pairs with adenine
. RNA polymerase joins nucleotides.
. Phosphide bond form between adjacent nucleotides.
. Pre mena Sliced and introns removed.

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

Describe how polypeptide is formed by translation of mRNA

A

. mRNA attaches to ribosome.
. tRNA Anticodons bind to complementary mRNA codons (2 bind at same time)
. TNA brings a specific amino acid.
. AA joints together with ATP
. tRNA released.
. Ribosome moves along mRNA to form the polypeptide 

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

What is a Homologous chromosome?

A

. Chromosome with the same genes equals homologous

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

What is meiosis?

A

. Produces gametes (haploid) using two divisions.
. Meiosis one is reduction division separation of homologous pair of chromosomes introduces variety.
. Miosis two is similar to my toes with separation of cyst chromatids for haploid cells produced with the diploid no. of chromosomes

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

How does meiosis lead to variation and genetic diversity?

A

. Produces unique gametes that are genetically different.
. Crossing over (prophase) with formation of chiasmata
. Homologous pies of chromosomes associates formed bivalent, chiasmata forms, equal length of non sister chromatids are exchanged, produces new combinations of alleles
. Independent assortment of homologous chromosomes.
. In metaphase one homologous pairs lineup at either side of the equator, completely random which side, once separated one of each pair ends up in Daughter celL, shuffling leads to different combinations of maternal and paternal chromosomes in daughter cells.
. Random meeting with Gammy results in variation.
. Mutations.

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

What is a mutation?

A

. Are changes in base sequence of chromosomes resulting in a new allele and can rise spontaneously during DNA replication.
. Substitution, deletion, insertion 

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are substitution deletion and insertion mutations?

A

. Substitution – one base minimum change for another during replication, only affects one cold on surrounding triplet stay sage.
. Deletion - one base Left out in DNA replication, results in frames shift all codons after mutation or affected.
. Insertion – an extra based added during DNA replication resulting in frames shift, all codons after mutation affected. 

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What does it mean that genetic code is degenerate

A

. Not obey substitutions cause change in sequence of encoded AA
. More than one codon code is the same AA
. Move my result in codon coding for same amino acid and t struc does not change

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

How could the change in a codon affect the genetic code

A

. Amino acid sequence changes
. Hydrogen/ionic/disulphide bonds between R group changes
. Tertiary structure changes
. Could make a S not complimentary to substrate so cannot form complexes

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

What is nondisjunction and how is it caused

A

. Chromosome mutation that occurs in mitosis where chromosomes not properly separated/not shared equally between daughter cells in metaphase and anaphase resulting in daughter cells have a different chromosome numbers
. Caused by spindle not attaching so not separating in anaphase or centromere not splitting in metaphase
. Down syndrome is as a result of nondisjunction

24
Q

What is a mutagenic agent and what does it cause

A

. Something that increases rate of Gene mutations
. Examples are UV, cigarette smoke, human papilloma virus, x-rays, benzyl peroxide, nitrate nitrate preservative, barbecuing

25
Q

Defined Univision and explain how gene mutation can have no effect on an individual or a positive effect on an individual

A

. Changing base/ nucleotide sequence
. Results in formation of new allele
. Genetic code is de generate a mutation is in an intron
. I was genuinely wanted but no effect on tertiary structure
. New allele is recessive so doesn’t influence phenotype
. Result in changing polypeptide that positively changes the properties
. May result in increased reproductive success or increase survival chances

26
Q

Define population

A

. A group of the same species living in a particular habitat

27
Q

Why is having a greater number of alleles in a population beneficial

A

. More alleles equals more genetic diversity
. How many ways of genetic diversity in population/species beneficial as give species growth a chance to survive a changing environment

28
Q

Define genetic diversity

A

. The total number of different alleles exist in a population

29
Q

Name factors that can affect genetic diversity

A

Lower
. Population size - smaller pops normally have lower G Div
. inbreeding
. Genetic bottlenecks
. Founder effect
Increase
. Migration-increases genetic diversity (called Gene flow)
. Mutations

. Natural selection - increase is beneficial allele frequency decreases nonbeneficial

30
Q

What is the genetic bottleneck

A

. Random event (cannot adapt) causing big reduction in population E.G.hunting
. Large number of population die before reproducing
. Reduces number of alleles in gene pool
. Survivors and larger population is produced from few individuals with smaller genetic diversity
. Survival is down to luck not genetic advantage

31
Q

What is the founder effect

A

. Fancy migration
. Few organisms from larger population start new population
. New population has less variety of alleles in initial gene pool
. Few individuals reproduce together to establish larger population with different frequencies of alleles than original population

32
Q

What is natural selection

A

. Changing our frequency population where an advantage allele increases
. When is the population becoming better adapted to survive in environment
. Caused by mutation, advantage in survival/reproductive success, reproduction, change in allele frequency

33
Q

How does mutation cause natural selection

A

. Natural selection starts with Gene mutates
. create new allele
. Some mutations harmful so less likely to reproduce
. Summarisations beneficial causing increased survival and reproduction E.G.camouflage

34
Q

Why does survival cause natural selection

A

. Individuals with particular alleles better able to face challenges of environment
. More likely to survive until age of sexual maturity and reproduce

35
Q

How does reproduction affect natural selection

A

. Organisms with great reproductive success with more offspring
. Organisms with good allele more likely to reproduce
. Offspring more likely to inherit good allele so next generation better adapted to the environment

36
Q

Summarise processes of natural selection

A

. Mutation occurs forming new allele with advantage
. Due to advantage organism more likely to survive and breed
. New Ali or pasta offspring making generation more suited to the environment
. Overtime many generations frequency of beneficial allele increases to the detriment of all the less beneficial alleles

37
Q

What is directional selection

A

. Caused by natural selection
. Occurs when environment changes
. Organisms with extreme alleles more likely to survive and reproduce
. Overtime most population will have extreme allele
. Example is antibiotic resistant bacteria

38
Q

What is stabilising selection

A

. Individuals with alleles for middle range more likely to survive and reproduce
. Occurs when environment is stable
. Conditions for average Alelle almost favourable
. Average hourly or shift towards the middle of the range

39
Q

What are anatomical, physiological, and behavioural adaptations

A

. Are caused by natural selection
. Anatomical adaptations – structural features affect shape or morphology of organism, observable, E.G.Wales with layer of blubber
. Physiological adaptations - processes within organism, adaptations of cells/organs are you don’t you don’t hibernation, camel store in fat
. Behavioural activation - ways organism acts, instinct Or learned behaviours, E.G.possums play dead near predators

40
Q

What are taxonomy, taxa, and taxoon

A

. Taxonomy is the science of classification
. Taxa is 8 individual groups used to classify organisms
. Taxon is each individual group

41
Q

What is phylogenic classification

A

. Attempts to arrange species into groups based on the evolutionary origins and relationships

42
Q

Define species

A

. Similar organisms which can interbreed and form fertile offspring

43
Q

What is the binomial system

A

. Used to avoid confusion with names around the world
. Includes genius and species name Capital genus lowercase species Homo sapien
. Do you keep ponds clean or frogs get sick
. Domain kingdom phylum class order family genus species

44
Q

Why can different species not breed

A

. Different species have different chromosomes
. Gametes contain different number of chromosomes
. Hybrid will have chromosomes but don’t have them on the bus pass preventing meiosis

45
Q

Why can observable features not be used in classification

A

. Species may look alike Due to convergent evolution
.  two organisms evolve similar features but not closely related
. Live in similar environments and expose the same selection pressures
. Similar I will provide similar selective advantages

46
Q

How are evolution of relationships between organisms found

A

. DNA/mRNA sequences, aa sequences - more similarities between bases/AA sequences = more closely related
. Immunology - similar proteins in organisms bind to same antibodies
. Antigens of one species another, larger precipitate forms equals more closely related organisms

47
Q

What is a phylogenic tree

A

. Show evolutionary relationships
. Each branch is a common ancestor

48
Q

What is courtship behaviour and why is it needed

A

. Used to attract mate of the right species
. Stimulates release of gametes
. Recognition /attraction of mate
. Indicate sexual maturity
. Formation of pi bond between two organisms to increase survival of offspring

49
Q

What is biodiversity

A

. Variety of organisms living in an area

50
Q

What is a habitat to

A

. Place where organism lives

51
Q

What is a community

A

. All the populations of different species in a habitat

52
Q

What is species richness

A

. Measure of the number of different species in a community
. Calculate if I take a random samples of community and counting numbers of different species

53
Q

What is biodiversity a measure of

A

. Species richness and abundance of each species

54
Q

What is index of diversity

A

Relationship between number of species in community and number of individuals in each species
. N = total number of organisms of all species
. n = total number of organisms of each species
. The higher d is the more diverse an area is
. Icl ur cooked lol

55
Q

What is agriculture and how does it reduce diversity

A

. Agriculture is the cultivation of soil to grow crops
CAN INVOLVE:
. Removing Woodland/hedgerows - less habitat, less VARIETY of food sources
. Using pesticides - kills insect species, reduces VARIETY of food sources for organisms higher on food chain
. using herbicide - kill species of weeds, reduces VARIETY of food for herbivores
. Growing one type of crop - less VARIETY in food source, less VARIETY of habitats

56
Q

What is conservation and what practices are in place to help it

A

. Conservation is a balance between the need for agriculture and maintaining biodiversity
. Endangered species are given legal protection you don’t you don’t restrictions on hunting or fishing
. Environmental stewardship scheme encourages farmers to conserve biodiversity
. Science of special scientific interest protected under wildlife and countryside act

57
Q

How do you collect species data from areas

A

. Divide area in Grid
. Use random number generator to generate coordinates
. Use large number of samples to collect reliable and representative sample to avoid bias
. RANDOM REPRESENTATIVE UNBIASED

Biology (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions