chalaza
Học thuậtThân thiện
Definition
Noun: 1. One of two spiral bands of tissue in an egg: A chalaza is one of two twisted, rope-like strands of albumen (egg white) that anchor the yolk to the center of the egg, suspending it within the shell membrane at either end. 2. The basal part of a plant ovule: In botany, the chalaza is the region of an ovule opposite the micropyle, where the integuments (protective layers) and the nucellus (central tissue) are joined together.
Usage Examples
- Zoological context (egg):
- The chalaza helps keep the yolk centered and protected.
- When you crack an egg, you can sometimes see the white, twisted cords of the chalaza.
- Botanical context (plant ovule):
- The chalaza is located at the base of the ovule, opposite the micropylar opening.
- Nutrients are often transported into the developing seed through the chalaza.
Advanced Usage
- The term is used almost exclusively in specialized biological descriptions. In everyday language regarding eggs, people might refer to it as "the white stringy bit" or simply "the egg anchor."
- The plural form is chalazae (pronounced /kəˈleɪziː/).
Variants and Related Words
- Chalazal (adjective): Relating to or of the nature of a chalaza.
- Example: The chalazal end of the ovule is where the seed connects to the plant.
Different Meanings
The word has two distinct, domain-specific meanings: 1. Zoological/Agricultural Meaning: The structural anchor within a bird's egg. 2. Botanical Meaning: A specific anatomical region in a plant's ovule (the precursor to a seed).
Synonyms
- For the egg structure: anchor, suspensory ligament (technical).
- For the plant structure: base of the ovule (descriptive). There are no common direct synonyms, as it is a precise anatomical term.
Notes
- This is a highly specialized scientific term. It is not used in general conversation.
- When used, the context (discussing eggs or plant reproduction) makes the intended meaning clear.
Noun
- one of two spiral bands of tissue connecting the egg yolk to the enclosing membrane at either end of the shell
- basal part of a plant ovule opposite the micropyle; where integument and nucellus are joined