why do scientists look at a sample of a population, rather than the whole population?
it is too time-consuming and would be impossible to catch all the individuals to sample the whole population.
4 of 21
why does a population sample have to be chosen at random?
to remove any bias and to make sure the results are accurate and reliable and are not due to chance.
5 of 21
what does the standard deviation of data show us?
the variation within a sample
6 of 21
what are the three main components of nucleotides?
phosphate, sugar and a base
7 of 21
which bases join together in a DNA molecule?
A-T C-G
8 of 21
what type of bonds join the bases together?
hydrogen bonds
9 of 21
why is DNA coiled so tightly?
so a lot of genetic material can fit into a small space
10 of 21
what is a DNA triplet?
three bases that code for one amino acid
11 of 21
what is an intron?
sections of DNA that do not code for amino acids
12 of 21
what is an allele?
A different form of a gene
13 of 21
how can mutation result in a non-functional enzyme?
mutations change the base sequence of an organisms DNA, so a non-functional or different protein could be produced
14 of 21
explain what is meant by the term haploid
one copy of each chromosome
15 of 21
explain what is meant by the term diploid
two of each chromosome
16 of 21
what happens to the chromosome number at fertilisation?
diploid number of chromosomes
17 of 21
what is a chromatid?
A chromatid holds the replicated DNA of each individual chromosome
18 of 21
how many divisions are there in meiosis?
2
19 of 21
how many cells does meiosis produce?
4
20 of 21
how does the founder effect reduce genetic diversity?
only a few organisms start a new colony so there is a lot of inbreeding and so the gene pool is limited to those individuals that started the colony unless there is any immigration.
21 of 21
Other cards in this set
Card 2
Front
what is interspecific variation?
Back
variation that exists between different species
Card 3
Front
which two kinds of factors can cause variation?
Back
Card 4
Front
why do scientists look at a sample of a population, rather than the whole population?
Back
Card 5
Front
why does a population sample have to be chosen at random?
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