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1.2 Modes of Specification — Test 1
Q1. Autonomous specification of cells results in which type of development?✓ Mosaic development
Q2. Conditional specification of cells results in which type of development?✓ Regulative development
Q3. A mosaic developmental pattern is always:✓ Autonomous
Q4. If a set of cells removed from an early embryo leads to an adult lacking the structures those cells would form, the embryo shows:✓ Autonomous (mosaic) specification
Q5. In regulative (conditional) development, removing some cells from an early embryo usually results in:✓ A normal embryo, as remaining cells compensate
Q6. Syncytial specification is best illustrated by the early development of:✓ Drosophila (insect) embryo
Q7. In syncytial specification, cell fates are influenced by:✓ Morphogen gradients acting on nuclei sharing one cytoplasm
Q8. When an 8-cell tunicate embryo is separated into blastomere pairs, each pair forms most tissues but NOT the nervous system. This indicates the nervous system arises by:✓ Conditional specification (needing cell interactions)
Q9. Autonomous specification depends mainly on:✓ Inherited cytoplasmic determinants
Q10. Conditional specification depends mainly on:✓ Interactions and signals between cells
Q11. A regulative embryo can sometimes form identical twins because:✓ Its early cells retain the potency to form a whole organism
Q12. In a strictly mosaic embryo, the fate of each blastomere is decided by:✓ The determinants it inherits at cleavage
Q13. Compared with autonomous specification, conditional specification gives an embryo greater:✓ Ability to regulate and repair after cell loss
Q14. The three basic modes of cell specification in animals are autonomous, conditional and:✓ Syncytial
Q15. Driesch's experiment separating early sea urchin blastomeres, each forming a complete larva, demonstrated:✓ Conditional (regulative) specification