DNA, genes and chromosomes Flashcards
what does diploid mean?
-2 copies of each chromosome
-46 altogether
haploid?
-23 chromosomes
DNA…
-2 strands coiled together in double helix
-held together by chemicals (bases)
what are the 4 bases?
Adenine, Cytosine, Guanine, Thymine
what is a gene?
-section of DNA that codes for a specific function
transcription processes (5)
-RNA binds to region of non coding DNA
-2 DNA strands unzip
-base pairing between DNA and RNA
-MRNA molecule moves out of nuclear
-joins with ribosome
translation processes (4)
-amino acids are brought to ribosomes by a transfer RNA
-pairing of codon and anticodon
-amino acids joined together by ribosome
-making a protein
what does asexual reproduction involve?
-one parent
-identical genes
-no variation
what is mitosis?
-cell reproduces itself
-by splitting to form 2 cells
-with identical sets of chromosomes
mitosis process…
-DNA duplicated
-chromosomes line up at centre of cell
-cell fibres pull them apart
-2 arms of each chromosome go to opposite ends of cell
-membranes form around each sets
-becoming nucei
-cytoplasm divides
sexual reproduction?
-2 parents
-diff genes
-genetically different
what are gametes? (haploid or diploid)
haploid (23 chromosomes)
what is fertilisation?
-male gametes fuse with female gamete to form zygote
-zygote divides by mitosis to form embroyo
what is meiosis?
-produces 4 haploid cells which are not identical
