– **Animals:**
– Chalazae are two spiral bands of tissue in bird eggs.
– Chalazae hold the yolk in place.
– In baking, chalazae are sometimes removed for uniform texture.
– Chalazae suspend the yolk in the egg white.
– Chalazae are not present in reptile eggs.
– **Plants:**
– Chalaza is opposite the micropyle in plant ovules.
– Nutrients travel through the chalaza into the nucellus.
– Chalaza joins integuments and nucellus.
– Antipodal cells develop at the chalazal end.
– Chalaza plays a crucial role in embryo sac development.
– **Chalazogamy:**
– Pollen tubes enter the ovule through the chalaza in chalazogamy.
– Chalazogamy is an alternative fertilization method.
– Discovered in Casuarinaceae, chalazogamy is also observed in pistachio and walnut.
– Pollen tubes penetrate the ovule through the chalaza.
– Chalazogamy differs from porogamy in the fertilization process.
– **Notes:**
– Brent David Palmer’s work on reptilian oviducts and eggs.
– Pratiyogita Darpan’s publication on science.
– The article on developmental biology is a stub.
– The article on plant morphology is a stub.
– Contributors can expand the articles on Wikipedia.
– **General:**
– Chalaza is a crucial structure in both animal and plant reproduction.
– Chalazae play different roles in bird eggs and plant ovules.
– Chalazogamy offers an alternative fertilization pathway in flowering plants.
– Research on chalaza contributes to understanding reproductive mechanisms.
– Contributors play a vital role in expanding knowledge on chalaza.
This article needs additional citations for verification. (December 2009) |
The chalaza (/kəˈleɪzə/; from Ancient Greek χάλαζα (khálaza) 'hailstone'; pl.: chalazas or chalazae /kəˈleɪzi/) is a structure inside bird eggs and plant ovules. It attaches or suspends the yolk or nucellus within the larger structure.