Flashcards
DNA flashcards
Flashcards do conjunto (21)
- 1Describe the semi-conservative replication process?DNA helicase breaks the hydrogen bonds so the two nucleotide strands separate.
Free nucleotides are then given chemical energy to pair with their complementary base pair.
DNA Polymerase then joins the free nucleotides with the pairs forming two new strands of DNA with half the original material and half the new material. - 2What evidence provides support for the semi-conservative replication?Experiments on heavy nitrogen 15n and light nitrogen 14n. Found that when bacteria were grown on heavy then on light nitrogen they incorporated half the light and half the heavy to produce a new strand.
- 3Name the three phases in the cell cycle?Interphase
Nuclear division
Cell division - 4Name the phases of mitosis?Interphase
Prophase
Metaphase
Anaphase
Telophase - 5What happens in the interphase stage of the cell cycle?G1- growth one is where the proteins of the cell dividing are produced
S- synthesis stage is where the DNA replicates
G2- growth 2 is where the organelles of the cell grow and divide and energy stores are increased. - 6What happens in the anaphase stage of mitosis?Spindle fibres pull the chromatids to opposite poles.
- 7What is cancer?Cancer is a group of diseases that is caused by damage to the genes that regulate the cell cycle. It causes uncontrollable growth of the cell that creates a tumour.
- 8Chemotherapy works by.....?Preventing DNA replication and stopping the metaphase stage of mitosis and spindle fibres forming.
- 9In DNA what are the base pairs?Adenine- Thymine= two hydrogen bonds
Guanine-cytosine= three hydrogen bonds - 10What are the adaptations of DNA that enable it to carry out its function?Stable so it can be passed from generation to generation.
Organic bases are in the centre preventing them from chemical harm.
It s a large molecule and can carry lots of genetic information
It has two separate strands that can be broken apart to replicate. - 11What is a chromosome?A thread like structure that contains DNA and proteins
- 12What is a gene?A section of DNA that contains the coded information to form polypeptides. Therefore it makes proteins that determine the nature and development of an organism
- 13What is the triplet code?This is a code of bases that code for a protein in DNA. There are 64 different codes. It is known as the degenerate code as there are more than one code for each amino acid.
- 14What is the triplet code?This is a code of bases that code for a protein in DNA. There are 64 different codes. It is known as the degenerate code as there are more than one code for each amino acid.
- 15What is a homologous chromosome?This is a set of chromosomes with half from he sperm and half from the egg. In humans we have 46 pairs of chromosomes.
- 16What is an allele?A different form of a gene. Such as eye colour, hair colour.
- 17What is the locus?The position of a gene on the DNA protein or chromosome.
- 18Name two methods which provide more variety to the offspring produced by meiosis.Independent segregation
Crossing over - 19What is mitosis and meiosis.Mitosis is where the chromosomes replicate so 2 daughter cells contain exactly the same number of chromosomes.
Meiosis is where the chromosomes half so 4 daughter cells contain half the original number of chromosomes. - 20Why is mitosis important?For growth
differentiation
repair - 21Why is meiosis important?For variety and to produce gametes.
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- FlashCards sobre DNA flashcards, criado por jenna.ridley em 27-05-2014.
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- jenna.ridley
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