Genetics Flashcards
What is Heredity
‘passing of features from one gen to another’
what are genetics
science that studies heredity
define: characteristic variation inherited traits acquired traits organisms population
1- is a feature of the body/behaviour
2- means differences in traits between individuals. can he inherited/acquired
3- comes from parents eg eye colour, hair colour
4- traits learned after birth eg food preference, language
5- any living thing
6- a group of the same organisms in one area
Define bases triplets gene chromosome genome
1- bases are made of dna sub units and are the letter in dna language
2- groups of 3 bases. are dna words and tells cells to put amino acids into a protein chain
3- is a sentence of dna and tells cells to make a whole protein
4- is a page of dna sentences
5- is complete book of dna page and tells cells to make every protein for organism.
what is dna and what does it do?
It is a molecule that stores coded info and is used for making protein. DNA tells a cell how to put the links into the protein chain.
what are proteins and what do they do?
it gives shape to cells and tissue in organisms and makes chemical reactions in cells go faster.
what are proteins made from?
Proteins are large molecules made from C, H, O & N.
Proteins are ‘chains’ built up from smaller molecules called amino acids.
what kind of molecule is dna called
self replicating molecule
How is Dna a self replication molecule?
If you split it down the middle, it can regrow into two identical new molecules.
What are the two matching strands that allow DNA to copy itself?
Template strand and Complementary strand
What is the shape of the dna molecule
double helix
What are the parts that make up dna
a sugar molecule
a phosphate molecule
a base molecule
look at diagram in onenote also
How does a nucleotide form?
sugar and phospate molecules join to each other. sugar joins to the base and together they form a nucleotide.
what are the 4 nucleotide bases?
Adenine, thymine, Cyostine and Guanine
How are the rungs in dna formed?
when 2 different bases join together
what is the aim of protein synthesis?
to express the information in the dna
what is protein synthesis and explain
-is process used by the body to make proteins. first step is transcription where mrna copies dna. the dna is unzipped and mrna strand copies a strand of dna.
what is a mutation? - explain
any permanent change in dna sequence of a gene
most mutations are harmful often causing genetic diseases such as cystic fibrosis/haemophilia. mutation rates are increased by mutagens including viruses, chemicals and radiation.
what are the 3 types of gene mutations
addition- adding of a base/dna segment
deletion- loss of a base/dna segment
substituition- exchange of one base for another
what are point mutations and frame shift mutations?
mutations which alter only one base.
addition and deletion are particularly serious point mutations because they cause an alteration in the genetic spelling. for this reason they are knows as frame shift mutations. they result in the production of non functional proteins.
what are the effects of mutations?
beneficial- lead to new proteins that give organism better chance of surviving
harmful- creates proteins that do not function normally if at all and can lead to genetic disorders
neutral- most mutations are neutral because they do not change the amino acid in the protein that they code for
neutral=silent mutation
what are the differences between sexual and asexual reproduction
sexual requires two parents however asexual only requires one. asexual is less time consuming, sexual is more time consuming. sexual provides more genetic variety however asexual reproduces identically.
what are the phases of mitosis- explain
Interphase- cell grows, replicates its chromosomes, and prepares for cell division
Prophase- chromatin condenses into chromosomes, and the nuclear envelope (the membrane surrounding the nucleus) breaks down
Metaphase-all the genetic material is condensing into chromosomes
Anaphase-each chromatid pair separates into two identical chromosomes that are pulled to opposite ends of the cell by the spindle fibres
Telophase- the spindle disappears and the nucleus reforms around each set of chromosomes.
define- somatic cells diploid and haploid gametes meiosis homologues
1- cells that make up the body of an organism
2- the number of chromosomes in somatic cells are diploid(2n) number of chromosomes in gametes are haploid(n )
3- cells for sexual reproduction
4- process in which one somatic cell divides to form four gametes
5- the twin of any chromosome is called its homologue.
what stages does meiosis occur
stage 1: homologues are separated
stage 2: the chromatids of each chromosome are seperated
phases of meisos
look in notebook
phases of meisos
look in notebook
comparison of meisois and mitosis
look in notebook there is a worksheet
what is karyotype and karyotyping
karyotype- an organised picture of a persons chromosomes
karyotyping- process of examining the chromosomes in a persons cells
what are the features scientists use to identify chromosomes
size, banding pattern and centromere position
what does karyotyping involve? explain
counting the number of chromosomes, determining sex and looking for faults.
counting involves working out if the correct number of chromosomes are present
next sex is determined
finally faults are identified if there are any
name the 3 kinds of faults in karyotyping
excessive chromosome numbers
missing chromosomes
missing genes
what happens when an individual has too many or too few chromosomes
-Klinefelter syndrome
turner syndrome
what happens if they have a missing piece in their chromosome
cri-du-chat syndrome
williams syndrome- missing genetc info from chromosome 7 including the gene elastin
what is the difference between DNA and rna
dna- double stranded Thymine (T) base
Deoxyribose sugar
rna- single stranded, uracil base, ribose sugar
