YR10 DNA - Topic Test Revision Flashcards
what makes up the DNA’s structure
phosphate and deoxyribonucleic sugar (backbone) and the 4 bases (adenine and thymine, guanine and cytosine) and hydrogen bonds holding the bases together
function of DNA
contains the genetic instructions for the development and function of living things. The main role of DNA in the cell is the long-term storage of information.
extracting DNA
crushing the strawberry
breaks open the cell
add detergent to the mixture
pulls apart the lipids and protein that makes up the membrane around the cell and nucleus.
add salt to the mixture
to neutralize the charge of the DNA’s sugar and phosphate
pour cold ethanol into the mixture
increases the yield of DNA, low temperatures protect the DNA by slowing down the enzymes that could break it apart.
precipitate DNA from the mixture
so you can get a clump of DNA which is visible
mitosis cell cycle step 1
I
interphase - 42 chromosomes replicate = 92 chromosomes
mitosis cell cycle step 2
P
prophase - chromosomes shorten and thicken
mitosis cell cycle step 3
M
metaphase - chromosomes line up on the equator
mitosis cell cycle step 4
A
anaphase - chromatids separate and start moving towards the poles
mitosis cell cycle step 5
T
telophase - chromatids are at the poles, and cell splits into two new cells (cytokinesis)
meiosis cell cycle step 1
M1
metaphase 1 - replicated chromosomes form (matching) homologous pairs, attached to spindle fibres and lined up in the middle
meiosis cell cycle step 2
A1
anaphase 1 - one replicated chromosome of each pair moves to each pole
meiosis cell cycle step 3
T1
telophase 1 - two cells are formed, each with one replicated chromosome
meiosis cell cycle step 4
M2
metaphase 2 - chromosomes line up on the equator attached to spindle fibres
meiosis cell cycle step 5
A2
anaphase 2 - chromatids separate and move to poles
meiosis cell cycle step 6
T2
telophase 2 - four cells result with one copy of each chromosome, they are haploid gametes.
mitosis definition
a part of the cell cycle when replicated chromosomes are separated into two new nuclei.
site of process in both
mitosis - somatic cells
meiosis - ovaries/testes
parent cells (haploid/diploid)
mitosis - diploid
meiosis - diploid
chromosome replication?
yes to both
line up in homologous pairs? (matching)
mitosis - no
meiosis - yes
fibres pull chromosomes apart?
yes to both
number of daughter cells
mitosis- 2
meiosis - 4
daughter cells haploid/diploid
mitosis - diploid
meiosis - haploid
nucleotide (DNA)
DNA is made up of this. Nucleotides are made up of sugar, phosphate and a base.
nucleotide (RNA) function
their role is to send the message from DNA to ribosomes
DNA is located where
the nucleus
scientists who discovered DNA
Oswald Avery
James Watson
Friedrich Miescher
Rosalind Franklin
what is the basic unit of DNA
a nucleotide
3 parts of DNA
sugar, phosphate and bases
describe the structure of a DNA molecule
twisted ladder, double helix, DNA twisted around a protein
whats a gene
genes are a part of DNA that codes a series of amino acids
describe a chromosome
- made from DNA molecule
- wound around histone (protein)
- x and y chromosomes
- contains genetic information
- double helix shape
- made from nucleotides
diploid
full chromosomes number of cells (normal)
haploid
half of the normal chromosome number
daughter cell
the new cells produced as a result of mitosis and meiosis
what parts of the body do mitosis occur
everywhere except the ovaries, testes and red blood cells
recombinant DNA
are DNA molecules formed by laboratory methods of genetic recombination to bring together genetic material from multiple sources, creating sequences that would not otherwise be found in the genome.
sugar + phosphate in dna
The sugar phosphate backbone is an important structural component of DNA.
double helix
refers to the structure formed by double-stranded molecules of nucleic acids such as DNA.
