The thin tubes that form between the centrioles during mitosis are the spindle fibres. Spindle fibers originates from a protein structure that divides the genetic material in a cell. They are necessary for the equal division of the chromosomes in a parental cell into two daughter cells during bth types of nuclear division (mitosis and meiosis). During the process of mitosis they are called mitotic spindles.
Biome
a complex biotic community characterized by distinctive plant and animal species and maintained under climatic conditions of the region, especially such as a community that has developed to climax.
The bird's eye contains a nictitating membrane which is a translucent, semitransparent inner eyelid. It sweeps across the surface of the eye enabling the bird to blink without losing sight of or without blocking their view.
Birds also have two different tear glands. One type of tear gland is located along the lower eyelid while the other is located at the base of the nictitating membrane. The second tear gland lubricates the bird's eyes whenever the nictitating membrane blinks.
You need two recessive alleles (xx). If even one dominant allele is present, the dominant trait will show (Xx or XX will both result in the dominant trait showing). That’s why they’re called dominant traits, because they overpower the recessive traits. In order for a recessive trait to show you must have two recessive alleles.
