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Variation in an offsprings genotype

process of meiosis
process of fertilisation
germ cell mutations


Independent assortment of chromosomes

is the process where the homologous chromosomes line up randomly at the equator and then move to seperate poles, independently of each other during the first division of meiosis


how many gametic combinations are possible if any chromosome from each of the 23 pairs is inherited by chance?

n= chrom pairs
or haploid number


Crossing over

sections of chromatids on adjacent chromosomes will break off and reconnect to the other chromosome

occurs when they r paired up on equator during 1st meiotic division


Random fertilisation

it is random as to which male gamete will fertilise which female gamete (with its 8 mil combs)

it increases variation on offspring
2^23x2^23=70 trillion



mutations in germ cells will ever have a chance to be passed onto next generation
Usually not beneficial tho
result in offspring not developing to maturity(so they can't pass on mutation)


what kind of germ cell mutations can happen

point mutations (SNPs). or can be due to mutagens or Chromosomal mutations like nondisjunction (fail to seperate)



is an interdisciplinary field that develops methods and software tools for understanding biological data


comparative genomics

is the study of the genome sequences of different species looking for similarities and differences


A phylogenic tree is

a tree that shows the evolutionary interrelationships among various species or other entities that are believed to have a common ancestor


A clade

is a common ancestor and all of its descendants


Deoxyribonucleic acid

macromolecule that is tightly wound up as chromosomes and contains genes which code for protein production



all of the genetic material contained on an organism or a cell (chroms and dan in chloroplasts and mitochondria)



a display of the number and appearance of chromosomes of an organism


DNA 2 functions

replication: DNA able to make copies of itself. before cell division DNA has to replicate so that each daughter cell has an exact set of chromosomes

Protein synthesis(gene expression): DNA can manufacture proteins for use in the body.
Genes in chroms contain the genetic code for producing proteins this ultimately controls the characteristics that the organism has


HOW is DNA chroms and genes related?

A DNA molecule in cells is organised into coiled structures called chromosomes. DNA wraps around histone proteins to fit in nucleus. Genes are the basic units of inheritance made of DNA segments


DNA structure

Has a double helix structure. Double stranded and the strands coil around each other like a twisted ladder.
each strand is polynucleotide made of many nucleotides joined together



a deoxyribose sugar
nitrogenous base(ACTG)
phosphate group


Sugar phosphate backbone

the sugar of one nucleotide joins to the phosphate group of the next.
The uprights of the ladder and are antiparallel. 1 runs in 3'-5' the other opposite


The nitrogenous bases in DNA

face inwards towards each other and are known as complimentary bases that make up the rungs of the ladder and are bonded by H bonds. BC of their them structure they follow the base pairing rule


The order of bases

is the code for making proteins


Most prokaryotic DNA

is in a circular ring in the nucleoid region of the cytoplasm
Also have plasmids, smaller rings of DNA that contain limited number of genes
they don't have a histone protein framework of eukaryotic cells



are made from linear sequence of aa that are joined to each other by peptide bonds resulting in a polypeptide chain
always contain CHON


Structural protiens

provide the shape and structure of the cell to carry out its function


Functional proteins:

transport, storage, receptor, motor, denese proteins and
Enzymes: specialised protein that control rate of them runs in cells
Hormones: chemical messengers made by certain them runs happening in cells


Primary structure

unique linear sequence of amino acids in the polypeptide chains that make the proteins


Secondary structure

coils or folds in the primary structure


Tertiary structure

folding in the secondary structures into a complex and compact molecule


Quaternary structure

the interaction between several polypeptide chains to produce the functional macromolecule


Gene expressions

is the process by which the instructions in our DNA are converted into a functional product (protein)
acts as on off switch to determine which proteins will be made and volume control to control how many proteins produced