number because a normal karyotype has 22 autosomes and 1 pair of s€x chromosomes
(sorry if I'm wrong)
Answer:
No one can see in total darkness. Fortunately, there’s almost always some light available. Even if it’s only dim starlight, that’s enough for your eyes to detect. What’s truly amazing is how little light is required for you to see.
Human eyes have two main features that help us see better in low light: the pupil’s ability to change size, and the eye’s two types of light-sensing cells.
Opening up to let in more light
Your pupils are the black areas at the front of your eyes that let light enter. They look black because the light that reaches them is absorbed inside the eyeball. It’s then converted by your brain into your perceptions of the world.
You’ve probably noticed that pupils can change size in response to light. Outside on a bright sunny day, your pupils become very small. This lets less light into the eye since there’s plenty available
Olá! Eu acredito que você colocou sua pergunta na categoria errada. Não se esqueça de fazer a pergunta na seção de idiomas estrangeiros para evitar que a pergunta seja excluída.
Com sua pergunta real, não acho que posso ajudá-lo com isso, e sinto muito por isso.
Answer: C. Black snakes will not prey on cane toads in areas where cane toads have been present for 40–60 years.
Explanation:
Cane toad secret a toxin called bufotoxin which is a defense mechanism against predators. These defense mechanism is capable of killing black snakes if they eat cane toads. Within a period of 40 to 60 years, the black snakes in these area will be aware of the presence of a toxin capable of killing them in cane toads and will not prey on them. This phenomenon is termed learned behavioral adaptation.
