Two adverbs of degree. もっと raises the scale ('more'). 一番 marks the top of a group ('the most / #1 / -est').
もっと + [adj/adv] ・ [group]の中で [A]が 一番 [adj]
もっと安いのはありますか?
Motto yasui no wa arimasu ka?
Do you have a cheaper one?
もっと (more) + 安い (cheap) + の (one) — 'a more-cheap one'
世界で一番愛してる。
Sekai de ichiban aishiteru.
I love you the most in the world.
世界で (in the world) + 一番 (most) + 愛してる (love)
家族の中で母が一番料理が上手です。
Kazoku no naka de haha ga ichiban ryouri ga jouzu desu.
In my family, my mother is the best at cooking.
家族の中で (within the group 'family') + 一番 (the most / #1) + 上手 (good at)
• Japanese adjectives don't change form for comparison (no '-er'/'-est'). You simply place もっと ('more') or 一番 ('most') in front of the unchanged adjective. • 一番 literally means 'number one'.
The JLPT rarely asks whether you recognise a pattern — it asks which of several similar patterns fits. These are the ones もっと is tested against.
より/のほうが compare two specific things ('A is more X than B'); もっと ('more') and 一番 ('most') state degree without necessarily naming what is being compared against.
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