How many trophic levels are there in the following food chain?

algae

mosquito larvae

dragonfly larvae - trout

What causes the uneven distribution of sunlight over the globe? A. the earth's distance from the sun B. the rate of the earth's rotation C. the earth's axial tilt D. the earth's seasons

Identify which statement is NOT correct about the eyes of mammals. A) Mammals have two eyelids, one upper and one lower eyelid. B) Mammal eyes have a lens which serves to focus the light.

How is sexual reproduction in flowering plants similar to an animal?

In winter in the Southern Hemisphere, the south end of Earth's axis is tilted away from the sun. A. True B. False

Which of the following is not a waste that is removed from the body through excretion? a. blood c. carbon dioxide b. salt d. urea

It contains two arteries and one vein entwined and enclosed by a protective, gristly substance called Wharton's Jelly. Blood constantly pulsates through it with every beat of your baby's heart. It is the A) villi. Eliminate B) placenta.

What happens when a baby did not recieve an X chromosome from either parent?

What happened in wwl

Mendel first crossed true-breeding plants to produce a second generation, which were then allowed to self-pollinate to generate the offspring. How do we name these three generations?

In humans, red-green color blindness is inherited as an X-linked recessive. If a color-blind woman marries a man with a normal vision what will be the expected phenotypes of their children with respect to this trait?