topic 3: genetics Flashcards
how do bacteria reproduce
asexually through binary fission
pros and cons of sexual reproduction
Pro - Because gametes fuse it leads to a large amount of variation
Pro - Population is less likely to wiped out by a disease or extreme event
Pro - Species can adapt to changing conditions by evolution
Con - It requires two parents
Con - Individuals may have have to spend large amounts of time and energy searching for a mate
Con - Many species spend resources impressing their mates even though it doesn’t aid survival
what is a genotype
the collection of genes an organism has
what is a gene
a section of DNA that controls part of a cells chemistry
what is a phenotype
the physical characteristics of an organism
(something you can see!)
what does meiosis create
4 genetically diverse haploid cells, which specialises into different sex cells
why is sexual reproduction better from asexual
.Allows for genetic variation/diversity
.This can allow for genetic mutation that can help individuals in a species to adapt and survive over generations
.
Which bases go together
.A+T
.C+G
what are the names of the four bases in order A,T,C,G
Adenine
Thymine
Cytosine
Guanine
what is DNA short for
DNA (deoxyribonucleic acid)
what is a Genome
the entire genetic makeup
what is the name for the shape of DNA
double helix
what are the pair of bases held together by
weak hydrogen bonds
how many pairs of bases create an amino acid
three
why is the structure of DNA described as
Cytosine and Thymine are bigger than Adenine and Guanine
True?
No
what is a chromosome
contains DNA
why are proteins polymers
they are made up of many amino acids joined together
differences between DNA compared mRNA and tRNA
different bases than DNA
DNA is in a double helix formation whereas mRNA and tRNA are both single stranded
why is washing liquid used to extract DNA
.breaks down the cell membrane and the nucleic membrane
what is each triplet of three bases
codon
what is an allele
a version of a gene
what is a mutation
a change in the base of a DNA molecule
what could cause a mutation
radiation
what is a gene
A piece of DNA that codes for a single protein
what is DNA
general idea
blueprint/code to make an individual
what is a chromosome
a long thread like strand of DNA found in the nucleus of a cell
what is a domminat allele
an allele which overrides other alleles (written with a capital letter)
what is the difference between homo and heterozygous
Homozygous is when your alleles are the same
Heterozygousl is two different the alleles
what was the work of Mendel
He cross breed peas to detect the power of inheritance
What is true breeding
when two pure organisms are bred with each other to determine which is the receive and which is the dominant
what is a codon
each amino acid is coded for by a sequence of three bases called condons
what are mutagens
something that causes/increases chance of a mutation
how can changes in the DNA sequence affect individuals and how could DNA sequencing a person influence treatments
.DNA has 4 different bases, and changes to the DNA are mutations, this will result in different alleles for these genes and so can affect the phenotype/produce variation
.DNA sequencing of an individual can identify genetic diseases, identify the risks of developing different disease and impact the individual to modify their lifestyle or seek medical treatment.
how can non-coding DNA still effect likelihood of mutations
three bullets
mutations in this region of DNA can effect how easy it is for RNA Polymerase to bind to it for protein synthesis
this effects how much mRNA is transcribed and so how much protein is made.
depending on the function of the protein how much is made may effect an organisms phenotype
how can genetic variants in coding DNA lead to changes in phenotype
.mutations occur in the base sequence within the gene of an organism
.this genetic variant could code for a different sequence of amino acids and so change the shape of the final protein produced changing its activity
.(activity of an enzyme could increase, decrease or stay the same)
.this can change the characteristics due to activity.
how can genome mapping help in medicine
.determine the risk of developing certain diseases caused by alleles of genes
.provide information on which course of treatment is best for individuals as certain alleles can affect how medicine works on people.
when do most mutations occur and explain the process
.during cell division, mutations can happen when there is a mistake in copying DNA during cell division. Where one base in a DNA sequence is replaced by another.
(it can happen naturally or due to radiation or certain substances)
why do most genetic mutations not effect the phenotype
the change occurs in the DNA sequence of a non-coding region of the DNA
