Why Would an Increased Level of Calcium Ions Be Observed

question 5

Multiple Choice

Why would an increased level of calcium ions be observed in a newly fertilized sea urchin egg?

• A)Calcium facilitates the binding of bindin to the bindin receptor.
• B)Increased calcium allows the sperm and egg nuclei to join efficiently,resulting in the formation of a zygote nucleus.
• C)Calcium promotes release of proteases from the egg,which digest the egg-cell receptor and prevent polyspermy.
• D)Calcium promotes an influx of water that results in a fertilization envelope.
• E)Answers C and D

---

Definitions:

Texture

The feel, appearance, or consistency of a surface, substance, or fabric, determined by its physical structure.

Sensory Adaption

The mechanism through which sensory receptors decrease in sensitivity to unchanging stimuli over a period.

Pseudostratified Columnar Epithelial Cells

A type of epithelial tissue that appears layered but is not, because cell nuclei are at different levels, and every cell is in contact with the basement membrane.

Basal Cells

Cells found at the bottom layer of the epidermis and hair follicles that are responsible for producing new skin cells.