t6-reproduction and genes Flashcards
what is needed in asexual reproduction and what is produced
-one parent
-offspring that are genetically identical to parent
describe sexual reproduction and what is produced
-2 parents
-offspring are genetically different
what is mitosis and describe stages
-asexual reproduction
-used for growth and repair
-DNA and subcellular structures are replicated
-chromosomes line up in centre of cell
-chromosomes are pulled apart to either end
-cytoplasm and cell membrane divide
-2 genetically identical daughter cells are formed
what is meiosis and describe stages
-sexual reproduction
1.chromosomes duplicate and cell divides
2.the 2 cells divide to form gametes. number of chromosomes is halved
3.fertilisation- male+female gametes fuse- 23 pairs of chromosomes in zygote
4.zygote divides by mitosis to form an embryo(group of identical cells)
what is DNA 4 points
-located in nucleus
-2 polymer chains with 4 nucleotides in the form of a double helix
-contains genes which code for specific proteins/characteristics
-4 bases- thymine, cytosine, guanine, adenine
what is the human genome
-complete set of DNA found in humans
uses of the human genome
3 points
-search for genes linked to disease
-helps us understand inherited disorders and their treatment
-can trace human migration patterns from the past
what is proteinsynthesis
-RNA moves from nucleus to ribosomes in cytoplasm where proteins are synthesised
-protein produced depends on template used
what do carrier molecules do
-bring specific amino acids to add to the protein in the correct order
what is a mutation
rare, random change in gene/chromosome. can be inherited
what are the three types of mutations
-substitutions: one of the bases is changed for another base
-insertion: an extra base is added to the sequence
-deletion: one of the bases is removed from the sequence
