Sea urchin embryo requires temperature of 23 degrees to cleave, in lower temperatures the embryo cleavage slows down.
Explanation:
Although the sea urchins live in sea water in cold temperature, they require a temperature of around 23 degrees to cleave for fertilisation if this temperature is reduced the process of cleavage slows down eventually depleting the urchin population.
The first option is correct (invasive species are harmful to biodiversity not beneficial)
The top of the water table.
Sunlight or artificial light is a source of glare.
8 chromosomes. In reality each egg and sperm have 23 chromosomes each in order for produce a healthy zygote