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3.1 Eggs & Yolk Types — Test 1
Q1. An egg with very little yolk evenly distributed through the cytoplasm is called:✓ Isolecithal (oligolecithal)
Q2. A frog egg, with a moderate amount of yolk concentrated toward one pole, is:✓ Mesolecithal
Q3. An egg with a large amount of yolk concentrated at the vegetal pole, as in birds and reptiles, is called:✓ Telolecithal
Q4. An insect egg, with yolk concentrated in the centre and cytoplasm around the periphery, is:✓ Centrolecithal
Q5. The amount and distribution of yolk in an egg mainly determines:✓ The pattern of cleavage the egg will undergo
Q6. Isolecithal eggs typically undergo which type of cleavage?✓ Holoblastic (complete)
Q7. Telolecithal eggs (heavily yolked) typically undergo:✓ Meroblastic (partial) cleavage
Q8. Centrolecithal eggs (as in insects) undergo which kind of cleavage?✓ Superficial cleavage
Q9. An egg essentially without yolk is described as:✓ Alecithal
Q10. In a telolecithal egg, the yolk-rich region is called the:✓ Vegetal pole
Q11. Mammalian eggs are nearly alecithal because the embryo:✓ Is nourished by the mother via the placenta
Q12. Why does a heavily yolked region of an egg cleave slowly or not at all?✓ The dense yolk physically impedes the cleavage furrow
Q13. The animal pole of a yolky egg is characterised by:✓ Active cytoplasm and the nucleus, with little yolk
Q14. Which sequence correctly ranks eggs by INCREASING yolk content?✓ Alecithal → isolecithal → mesolecithal → telolecithal
Q15. Fishes such as the zebrafish have telolecithal eggs and therefore show:✓ Meroblastic discoidal cleavage on top of the yolk
Q16. The polarity (animal–vegetal axis) established in the egg is important because it:✓ Helps set up the future body axes of the embryo
Q17. Oligolecithal is another term for an egg that is:✓ Isolecithal (with little, evenly distributed yolk)
Q18. Reptilian and avian eggs store large yolk reserves mainly to:✓ Nourish the embryo during long development outside water