Topic 3 - Genetics Flashcards
what are found inside the nucleus?
chromosomes
Which substance forms a long strand in each chromosome?
dna
How do body cells make copies of themselves?
mitosis
How many chromosomes are there in a human body cell nucleus?
46
what happens in fertilisation?
two gametes fuse
what is the cell formed in fertilisation called?
zygote
what is the name of the human gamete?
sperm cell
The DNA strand in a chromosome contains sections that carry instructions for characteristics. What are these sections called?
genes
What molecule forms the genome of an organism?
dna
where are genes found?
[in sections of DNA] on chromosomes
What does a gene carry the instructions for?
making a protein
A protein is made by linking together smaller molecules. What are these smaller molecules called?
amino acids
what is a group of molecules joined together called?
a ploymer
A human cell contains 46 strands of DNA. Is it diploid or haploid?
diploid
are the cells produced by meiosis haploid or diploid?
haploid
Are the cells produced by mitosis haploid or diploid?
diploid
What shape is DNA?
double helix
What is a chromosome made out of?
dna and proteins
What are the letters of the bases that form the DNA code?
A,C,T,G
How do these bases pair up in DNA?
A&T , C&G
Give an example of a protein
enzymes
how is the active site of an enzyme formed?
folding of protein
why are proteins polymers
they are made of many amino acids joined in a chain
how many bases does a codon contain?
3
whats a mutation
a change in the bases of a gene that creates a genetic variant
whats an organisms phenotype?
its observed characteristics
whats an organisms phenotype?
its observed characteristics
what are different versions of the same gene called?
alleles
what sort of variation do alleles cause in organism
genetic variation
what word describes both alleles are the same?
homozygous
if a dominant allele has the letter A, how would u show an organism is heterozygous?
Aa
what word describes the characteristics of a gene?
a phenotype
what word describes the alleles of a gene found in an organism
genotype
whats a recessive allele
a
a genotype is written QQ. What does this tell you?
It is homozygous and dominant
whats probability?
the chance of an event happening
how can we show the possible offspring through two peoples alleles?
punnett square
what do x and y chromosomes make?
male
probibalitly of having a boy
50%
Formation of DNA
- Two strands coil to form a double helix
- Strands linked by complimentary base pairs
- Base pairs joined by weak hydrogen bonds
What are the DNA bases made out of
Sugar & phosphate
How are the base pairs joined together?
Weak hydrogen bonds
What’s the first step of extracting DNA from fruit?
Use detergent to break down cell membrane and release DNA
Why do you add salt when extracting DNA in fruit cells
Salt makes the DNA stick together
What’s the last step of extracting DNA from fruit cells?
Add ice-cold ethanol
Why do You add ethonal to fruit cells?
because the DNA isn’t soluble in cold alcohol
What happens after alchol has been added?
It will appear as a white stringy precipitate
4 stages of genetic engineering
- Gene extracted using restricted enzyme
- Plasmid extracted from bacterial cell
- Enzyme used to cut open plasmid
- Gene inserted into plasmid, sealed by an enzyme.
