Answer:
The double helix describes the appearance of double-stranded DNA, which is composed of two linear strands that run opposite to each other, or anti-parallel, and twist together. Each DNA strand within the double helix is a long, linear molecule made of smaller units called nucleotides that form a chain.
Explanation:
What causes Evolution-
Mutation
Migration
Genetic drift
natural selection
Answer:
<u>Sister chromatids are identical forms of chromatids of a chromosomes. They are mostly formed by semi-conservative replication of DNA molecule of a single chromosome.Thus they are like </u><u>'photocopies' </u><u> of original parent chromosomes; joined together at the Centromere</u>.
They are exactly similar in all ramification; with the same gene and allele compositions..
<u>However; slight differences arise between the two identical sisters due to </u><u>mutation</u><u> from</u><u> errors </u><u>at replication;and also in the length of telomere repeats.</u>
Non-sister chromatids are dissimilar forms of chromatids of a chromosomes formed when each half of a chromosome at fertilisation from separate haploid sex-cells, of each parent. fused.They contain different genetic composition;because they are not on the same homologous chromosomes.Therefore crossing -over ensure variation.
<u>However, they are genetically similar in composition; if they are contained in homologous chromosomes</u>. This is because Synapsis of bivalent of these chromosomes allow genetic material to be shared by chromosomal crossing-over between the non-sister chromatids on the chromosomes ; therefore identical genetic characteristics are shared .
Explanation:
Bones teeth and maybe scull
Water is able to dissolve varieties of all kinds of different substances, which is the whole reason why it's such a good solvent.
It's also called the "universal solvent" bcuz it dissolves more substances than any liquid has ever been able, and this allows the water molecule to become attracted many other kinds of molecules :)
Glad I could help! Byee