Unit 4 AOS 2 Flashcards
True or false
Everyone has two copies of each gene
True
One form of a gene
Allele
The observable characteristics of an organism
Phenotype
What makes up a phenotype?
Genotype + environment
The section of DNA that codes for a protein (to give a trait)
Genes
The combination of alleles for a gene
Genotype
The entire set of an individuals genes
Genome
A pair of chromosomes that have genes in the same locations
Homologous chromosomes
Requires only one allele to show in the phenotype, represented by a capital letter
Dominant trait
Requires two alleles to show in the phenotype, represented by a lower case letter
Recessive trait
The information in a gene used to synthesize protein
Gene expression
A group of organisms of the same species living within the same geographical area at the same time
Population
Things that change the phenotype in a population
Polygenes
Sexual reproduction
Mutations
Biochemical
Physiological influences
Developmental stages
Behaviour
Monomorphic variation
Polymorphic variation
Polygenes
Many genes contributing to a trait
Many genes contributing to a trait
Polygenes
Causes the recombination of alleles
Sexual reproduction
_________ produce new alleles
Mutations
Acidic soils (low pH) = blue flowers. Alkaline soils (high pH) = pink flowers
What is this an example of?
Biochemical influences
The arctic fox makes many physiological changes depending on the season
What is this an example of?
Physiological influences
An adult python is green, whereas a juvenile python is yellow
What is this an example of?
Developmental stages
Genes of two chromosomes that switch during meiosis and decides the alleles of the offspring
Crossing over
The annual migration of red crabs on Christmas Island changes the population
What is this an example of?
Behaviour
When members of a population may show no variation of an observable trait
Monomorphic variation
When there are two or more variations for an observable trait
Polymorphic variation
The complete set of alleles carried by all the individuals in a population
Gene pool
The sum of all variation in a population (includes all the possible alleles present)
Gene pool
______ ___________ can represent the gene pool
Allele frequencies
All the genetic information (the base pairs) found in one complete set of an organism’s genetic material
Genome
How frequent an allele occurs in a population
Allele frequency
What causes allele frequencies to change
Mutations as a source of new alleles
Different types of mutations
Environmental selection pressures
Gene flow (migration and inter-breeding
Genetic drift (bottleneck & founder effect)
The permanent change in the nucleotide sequence of an organism, resulting in changes to proteins
Mutations
Mistakes in DNA replication can cause _________
Mutations
Two types of causes to mutations
Spontaneous
Induced
What is spontaneous mutation
Naturally occurring and random
What is induced mutation
Exposure to mutagenic agents
What will happen if the repair of mutations cannot be made
Cells will undergo apoptosis
What will happen if there is a large exposure to a mutagen
The body will be unable to repair all the damage
What is a nucleotide
Basic building block of DNA/RNA composed of a sugar, a nitrogenous base and a phosphate group
Types of genetic mutations
Point mutations
Block mutations
Chromosome number mutations
A mutation that affects a single nucleotide in the sequence of a gene
A point mutation
Two different types of point mutations
Substitution mutations
Frameshift mutations
A mutation that occur when a single nucleotide in either DNA or RNA is exchanged for another
Substitution mutation
Three different types of substitution mutations
Silent mutations
Missense mutations
Nonsense mutations
Mutations caused by the insertion or deletion of a single nucleotide which alters the entire sequence of amino acids from the point of mutation onwards
Frameshift mutations
A mutation that changes a segment of a chromosome leading to large scale changes to the DNA of an organism. May result in a number of genes may be moved around. Includes; inversion, deletion, duplication and translocation
Block mutations
What mutation occurs during crossing over
Block mutations
When does block mutation occur in meiosis
During crossing over
The four types of block mutations
Inversion
Deletion
Duplication
Translocation
Inversion (block mutation)
Reversal of a section of DNA (causes a block of genes to be inverted)
Deletion (block mutation)
Removal of a section of DNA
Duplication (block mutation)
Replication of a section of DNA (lengthening of DNA)
Translocation (block mutation)
Switching of two sections of DNA on different chromosomes
Changes to the number of specific chromosomes (missing/extra)
Aneuploidy
Changes to the numbers of whole sets of chromosomes (e.g. common in plants, frogs, salamanders & leeches)
Polyploidy
Failure in anaphase I and/or II of meiosis
Results in gametes with an incorrect number of chromosomes (aneuploidy)
Non-disjunction
Difference between aneuploidy and polyploidy
Aneuploidy refers to a numerical change in part of the chromosome set, whereaspolyploidy refers to a numerical change in the wholeset of chromosomes
Giant strawberries are an example of selective breeding for __________
Polyploidy
Can result in immediate speciation (new species)
Polyploidy
“Survival of the fittest!”
Natural selection
What is ‘fitness’ in biology
A measure of reproductive success
Individuals which are more adapted to a particular environment and so are able to survive, reproduce and make a greater contribution to the gene pool of the next generation, they are ____________ ______
biologically fitter
The process of natural selection
Variation in the population
The individuals whose phenotype is not suited to the environment die (selected against)
Those individuals most suited to their environment survive (selected for)
The survivors have offspring
Offspring look like parents
Allelic frequency changes
Four conditions of natural selection
Variation
Selection pressure
Selection advantage
Heritability
Variation
Individuals in a population that vary genetically, which leads to phenotypic differences
Individuals in a population that vary genetically, which leads to phenotypic differences
Variation
Selection pressure
Environmental factors that impact the survivability of an organism within a population and their ability to reproduce
Environmental factors that impact the survivability of an organism within a population and their ability to reproduce
Selection pressure
Selection advantage
Individuals with phenotypes that are fitter or more advantageous under the environmental selection pressure
Individuals with phenotypes that are fitter or more advantageous under the environmental selection pressure
Selection advantage
Heritability
A heritable advantageous trait, allowing it to be passed on from the parents to the offspring and therefore increase frequency of the advantageous allele
A heritable advantageous trait, allowing it to be passed on from the parents to the offspring and therefore increase frequency of the advantageous allele
Heritability
Characteristics of primates
Sexually dimorphic
Live in social groups
Large forward-facing eyes
Large brain = intelligence
Opposable thumbs
Flat fingernails
Sensitive fingertips
What is sexual dimorphism
A difference in features between males and females
Homonoid
Human-like
True or false
Apes have tails
False
What comprises in the Strepsirrhini suborder
Lemurs
Lorises
What comprises in the Haplorrhini suborder
Tarsiers
New world monkeys
Old world monkeys
Gibbons
Orangutans
Gorillas
Chimpanzees
Humans
What comprises in the monkey superfamily
New world monkeys
Old world monkeys
What comprises in the Hominoidea (apes) superfamily
Gibbons
Orangutans
Gorillas
Chimpanzees
Humans
What comprises in the Hominidae ( great apes) family
Orangutans
Gorillas
Chimpanzees
Humans
True or false
Gibbons are in the Hylobatidae subfamily
True
What comprises in the Hominini tribe
Humans and our extinct upright walking human ancestors (e.g. australopithecus, paranthropus, kenyanthropus, sahelanthroupus and anything else in the genus homo)
True or false
In Australia, a chimp is a hominid, NOT a hominin
True
What are hominoids
Apes but not monkeys, tarsiers or lemurs
What are hominids
Great apes but not other apes such as gibbons
What is selective breeding/artificial selection
Mating individuals with traits that are desirable to cause a change in the allele frequencies of the population and steer evolution
Similar to natural selection, although the selecting agent is a person and is instead artificial as opposed to natural
Causes of natural selection
Predator
Disease
Shortage of food
Define artifical
Made or produced by human cleverness or ingenuity rather than naturally occurring
