Genetics of living systems M6
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- Created by: kaylee17ne
- Created on: 14-03-24 22:07
Mutation is a change in __________ of bases in DNA. What are the 3 types of mutations?
If one nucleotide is affected, it's called a _____ mutation.
If one nucleotide is affected, it's called a _____ mutation.
Mutation is a change in sequence of bases in DNA. Mutations are substitution, deletion, or insertion. If one nucleotide is affected, it's called a point mutation.
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Substitution:
When a single nucleotide is substituted it changes the _____ in which it occurs. If the new _____ codes for a different amino acid, this changes the ________ structure of the protein.
When a single nucleotide is substituted it changes the _____ in which it occurs. If the new _____ codes for a different amino acid, this changes the ________ structure of the protein.
When a single nucleotide is substituted it changes the codon in which it occurs. If the new codon codes for a different amino acid, this changes the primary structure of the protein.
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The _________ nature of the genetic code may mean that the new codon still codes for the same amino acid, leading to no change in the protein __________.
The degenerate nature of the genetic code may mean that the new codon still codes for the same amino acid, leading to no change in the protein synthesised.
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Insertion and deletion:
The triplet code means base sequences are transcribed in non-_________ groups of 3. Each 3 codes for one amino acid. The mutation moves the _______ frame of the base sequences, changing every codon
The triplet code means base sequences are transcribed in non-_________ groups of 3. Each 3 codes for one amino acid. The mutation moves the _______ frame of the base sequences, changing every codon
The triplet code means base sequences are transcribed in non-overlapping groups of 3. Each 3 codes for one amino acid. The mutation moves the reading frame of the base sequences, changing every codon from the mutation point.
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Effects of mutations
No effect means there's no effect on the _________ of an organism because normally functioning proteins are still synthesised
No effect means there's no effect on the _________ of an organism because normally functioning proteins are still synthesised
No effect means there's no effect on the phenotype of an organism because normally functioning proteins are still synthesised.
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Damaging effect means the _________ of an organism is affected negatively because proteins are no longer synthesised, or if they are they don't ________. This interferes with essential processes.
Damaging effect means the phenotype of an organism is affected negatively because proteins are no longer synthesised, or if they are they don't function. This interferes with essential processes.
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Beneficial effect means a protein synthesised results in a new and useful _______________ in the phenotype. This is rare.
Beneficial effect means a protein synthesised results in a new and useful characteristic in the phenotype. This is rare.
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What are the 4 mechanisms that affect the transcription of genes?
- chromatin remodelling
- histone modification
- the lac operon
- cyclic AMP
- histone modification
- the lac operon
- cyclic AMP
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Chromatin remodelling:
_____________ is tightly wound DNA causing chromosomes to be visible during division. __________ is loosely wound DNA present during interphase.
_____________ is tightly wound DNA causing chromosomes to be visible during division. __________ is loosely wound DNA present during interphase.
Heterochromatin is tightly wound DNA causing chromosomes to be visible during cell division.
Euchromatin is loosely wound DNA present during interphase.
Euchromatin is loosely wound DNA present during interphase.
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Transcription isn't possible when DNA is tightly wound because RNA __________ can't access the genes, but in euchromatin they can be freely ___________. Protein synthesis occurs during interphase to ensure proteins for cell division are synthesised in ___
Transcription isn't possible when DNA is tightly wound because RNA polymerase can't access the genes, but in euchromatin they can be freely transcribed. Protein synthesis occurs during interphase to ensure proteins for cell division are synthesised in tim
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Histone modification:
Addition of _____ or _______ groups reduces the + charge on histones, causing DNA to coil less tightly, allowing certain genes to be __________. Addition of _____ makes histones more hydrophobic, DNA coils tightly, prevents _________
Addition of _____ or _______ groups reduces the + charge on histones, causing DNA to coil less tightly, allowing certain genes to be __________. Addition of _____ makes histones more hydrophobic, DNA coils tightly, prevents _________
Addition of acetyl or phopshate groups reduces the + charge on histones, DNA coils less tightly, certain genes are transcribed. Addition of methyl groups make histones more hydrophobic, DNA coils tightly, prevents transcription. This is called epigenetics
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Lac operon:
A group of genes which are under the control of the same ________ and are _________ at the same time. If the products of the genes aren't needed, these genes can be ________ off.
A group of genes which are under the control of the same ________ and are _________ at the same time. If the products of the genes aren't needed, these genes can be ________ off.
A group of genes which are under the control of the same mechanism and are expressed at the same time. If the products of the genes aren't needed, these genes can be switched off.
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Operon is a group of 3 genes: lac_, lac_ and lac_. They are structural genes as they code for 3 enzymes and transcribed onto a single ____. Lac_ is a regulatory gene which codes for a repressor protein.
Operon is a group of 3 genes: lacA, lacY, lacZ involved in lactose metabolism. Structural genes which code for 3 enzymes and transcribed onto a single mRNA. LacI is a regulatory gene which codes for a repressor protein.
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A repressor protein prevents transcription of structural genes in the absence of _______. Binds to the operator, preventing RNA ________ binding to DNA and beginning transcription. The DNA binding site is called the _________.
A repressor protein prevents transcription of structural genes in the absence of lactose. Binds to the operator, preventing RNA polymerase binding to DNA and beginning transcription. The DNA binding site is called the promoter.
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Lactose is present, binds to ________ protein, changes shape, no longer binds to ________, RNA polymerase binds to ________, 3 structural genes are transcribed, enzymes synthesised.
Lactose is present, binds to repressor protein, changes shape, no longer binds to operator, RNA polymerase binds to promoter, 3 structural genes are transcribed, enzymes synthesised.
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Cyclic AMP:
Binding of RNA ________ results in a slow transcription rate, needs to be increased to produce the right quantity of enzymes to metabolise _______. So cAMP ________ protein also binds.
Binding of RNA ________ results in a slow transcription rate, needs to be increased to produce the right quantity of enzymes to metabolise _______. So cAMP ________ protein also binds.
Binding of RNA polymerase results in a slow transcription rate, needs to be increased to produce the right quantity of enzymes to metabolise lactose. So cAMP repressor protein also binds.
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What are the 2 mechanisms which affect post-transcriptional control?
- RNA processing
- RNA editing
- RNA editing
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RNA processing:
Product of transcription is pre-____, modified to form mature ____. A cap (modified nucleotide) added to the _' end and a tail (chain of adenine) added to _' end.
Product of transcription is pre-____, modified to form mature ____. A cap (modified nucleotide) added to the _' end and a tail (chain of adenine) added to _' end.
Product of transcription is pre-mRNA, modified to form mature mRNA. A cap (modified nucleotide) added to the 5' end and a tail (chain of adenine) added to 3' end.
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These help _______ the mRNA and delay __________ in the cytoplasm. Cap also binds mRNA to _______. Splicing occurs where the RNA is cut at specific points, the ______ are removed (non-coding DNA), _____ (coding DNA) are joined together which occurs in the
These help stabilise the mRNA and delay degradation in the cytoplasm. Cap also binds mRNA to ribosomes. Splicing occurs where the RNA is cut at different points, the introns are removed and the exons are joined together which occurs in the nucleus.
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RNA editing:
sequence of mRNA can be changed through ________, ________, or ____________. Same effect as point mutations, resulting in synthesis of different proteins with different ______. Increases the range of proteins a single mRNA produces.
sequence of mRNA can be changed through ________, ________, or ____________. Same effect as point mutations, resulting in synthesis of different proteins with different ______. Increases the range of proteins a single mRNA produces.
sequence of mRNA can be changed through addition, deletion or substitution. Same effect as point mutations, resulting in synthesis of different proteins with different functions. Increases the range of proteins a single mRNA produces.
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What are the 4 mechanisms which affect translational control?
- degradation of mRNA
- binding of inhibitory proteins to mRNA
- activation of initiation factors
- protein kinases
- binding of inhibitory proteins to mRNA
- activation of initiation factors
- protein kinases
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Degradation of mRNA:
the more resistant the molecule, the longer it lasts in the ________, the greater quantity of protein _________.
the more resistant the molecule, the longer it lasts in the ________, the greater quantity of protein _________.
the more resistant the molecule, the longer it lasts in the cytoplasm, the greater quantity of protein synthesised.
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Binding of inhibitory proteins to mRNA:
prevents mRNA binding to ________, therefore preventing the synthesis of proteins.
prevents mRNA binding to ________, therefore preventing the synthesis of proteins.
prevents mRNA binding to ribosomes, therefore preventing the synthesis of proteins.
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Activation of initiation factors:
aid the binding of mRNA to ________,
aid the binding of mRNA to ________,
aid the binding of mRNA to ribosomes
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Protein kinases:
enzymes that catalyse the addition of ________ groups to proteins, changing the ______ structure and the function of the protein.
enzymes that catalyse the addition of ________ groups to proteins, changing the ______ structure and the function of the protein.
enzymes that catalyse the addition of phopshate groups to proteins, changing the tertiary structure and the function of the protein.
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4 modifications affecting post-translational control:
- addition of non ______ groups
- formation of _____ such as disulfide bridges
- _______ or ________ of proteins
- cAMP
- addition of non ______ groups
- formation of _____ such as disulfide bridges
- _______ or ________ of proteins
- cAMP
- addition of non protein groups
- formation of bonds such as disulfide bridges
- folding or shortening of proteins
- cAMP
- formation of bonds such as disulfide bridges
- folding or shortening of proteins
- cAMP
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Body plans - homeobox genes
A group of genes which all contain a homeobox. This is a DNA section ___ base pairs long which codes for a part of the protein that is highly ________ in plants, animals and fungi. The part is called a _________, switching gene
A group of genes which all contain a homeobox. This is a DNA section ___ base pairs long which codes for a part of the protein that is highly ________ in plants, animals and fungi. The part is called a _________, switching gene
A group of genes which all contain a homeobox. This is a DNA section 180 base pairs long which codes for a part of the protein that is highly conserved in plants, animals and fungi. The part is called a homeodomain, switching genes on or off.
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Hox genes:
One group of homeobox genes that are only present in _______. Responsible for correct __________ of body parts. Hox genes are found in gene _______. The order in which they appear along the chromosome is the order in which the effects are _____
One group of homeobox genes that are only present in _______. Responsible for correct __________ of body parts. Hox genes are found in gene _______. The order in which they appear along the chromosome is the order in which the effects are _____
One group of homeobox genes that are only present in animals. Responsible for correct positioning of body parts. Hox genes are found in gene clusters. The order in which they appear along the chromosome is the order in which the effects are expressed in a
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Layout of living organisms:
__________ animals have 2 primary tissue layers and __________ animals have 3 primary tissue layers. Hox genes in the head control ________ development, hox genes in the thorax control _____ or limbs or ____ development.
__________ animals have 2 primary tissue layers and __________ animals have 3 primary tissue layers. Hox genes in the head control ________ development, hox genes in the thorax control _____ or limbs or ____ development.
Diploblastic animals have 2 primary tissue layers and triploblastic animals have 3 primary tissue layers. Hox genes in the head control mouthparts development, hox genes in the thorax control wings or limbs or ribs development.
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Vertebrae and associated structures have developed from ______, which are segments of the embryo. These are directed by ___ genes to develop in a particular way depending on their _______ in the sequence.
Vertebrae and associated structures have developed from somites, which are segments of the embryo. These are directed by Hox genes to develop in a particular way depending on their position in the sequence.
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Mitosis in controlling body plans:
increases the number of cells leading to ______
increases the number of cells leading to ______
increases the number of cells leading to growth.
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Apoptosis in controlling body plans:
Apoptosis is programmed cell _____. It shapes body parts by removing unwanted ____ and ______. Cells undergoing apoptosis release chemical signals, stimulating ______ and cell ___________, leading to remodelling of tis
Apoptosis is programmed cell _____. It shapes body parts by removing unwanted ____ and ______. Cells undergoing apoptosis release chemical signals, stimulating ______ and cell ___________, leading to remodelling of tis
Apoptosis is programmed cell death. It shapes body parts by removing unwanted cells and tissues. Cells undergoing apoptosis release chemical signals, stimulating mitosis and cell proliferation, leading to remodelling of tissues.
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Factors affecting regulatory gene expression:
Stress, the ________ balance of an organism becomes upset, due to change in temperature or light (external) or _______ release (internal).
Stress, the ________ balance of an organism becomes upset, due to change in temperature or light (external) or _______ release (internal).
Stress, the homeostatic balance of an organism becomes upset, due to change in temperature or light (external) or hormone release (internal).
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Other cards in this set
Card 2
Front
Substitution:
When a single nucleotide is substituted it changes the _____ in which it occurs. If the new _____ codes for a different amino acid, this changes the ________ structure of the protein.
When a single nucleotide is substituted it changes the _____ in which it occurs. If the new _____ codes for a different amino acid, this changes the ________ structure of the protein.
Back
When a single nucleotide is substituted it changes the codon in which it occurs. If the new codon codes for a different amino acid, this changes the primary structure of the protein.
Card 3
Front
The _________ nature of the genetic code may mean that the new codon still codes for the same amino acid, leading to no change in the protein __________.
Back
Card 4
Front
Insertion and deletion:
The triplet code means base sequences are transcribed in non-_________ groups of 3. Each 3 codes for one amino acid. The mutation moves the _______ frame of the base sequences, changing every codon
The triplet code means base sequences are transcribed in non-_________ groups of 3. Each 3 codes for one amino acid. The mutation moves the _______ frame of the base sequences, changing every codon
Back
Card 5
Front
Effects of mutations
No effect means there's no effect on the _________ of an organism because normally functioning proteins are still synthesised
No effect means there's no effect on the _________ of an organism because normally functioning proteins are still synthesised
Back
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