How long ago did homo sapiens appear

The many kinds of dogs are all of the same species because

What force keeps stable nuclei permanently together?

When a plant starts to reproduce, auxins are released. Also a large amount of sugar is used to creat energy to build reproductive pollen and fruits. Which main plant tissue are working together

What naturally occurring metal slows fetal and child development and causes irreversible deficits in brain function? lead mercury potassium asbestos?

Is evolution and speciation the same process?

Which of the following is likely to be made from a thermoplastic? -a car bumper -a grocery bag -support beams for a building -lawn furniture

Is there any place on Venus humans could live? Explain.

The brain reaches its maximum size between ages 5 and 7. True or false

The seafloor and continental land are similar in age. a) true b) false

Which of these vaccines must replicate to stimulate an immune response? hpv9. mmr. mcv4. tdap?