What is the the outer boundary of the cell of an animal called?

a. Wall

b. Gate

c. Nucleus

d. Membrane

As humans increased the control of fire, which of the following happened? a No change in the number of calories consumed. b An increase in the number of calories consumed. c A decrease in the number of calories consumed.

Video link: What is Natural Selection? 1. What do the call the idea that traits are passed down from generation to generation and sometimes undergo changes or modifications over time.

Why are plants unable to grow at the bottom of lakes? a. The water is colder at the bottom. b. Sunlight does not reach the bottom. c. Groundwater feeds into the bottom. d. Less fresh water is found at the bottom.

The main purpose of the voyage of the hms beagle was to

A pea plant that has round seeds has the genotype Rr. It is crossed with a pea plant that has wrinkled seeds and the genotype rr. What is the probability that the offspring will have wrinkled seeds?

What is a niche? i need answers!

What passage carries food between the pharynx and the stomach?

Coiled tube in which the greatest amount of digestion and absorption take place

Most of the world's food supplies comes from 14 species of crops. Which of these crops are the most important? A) corn, potatoes, and hay B) wheat, rice, and sugarcane C) alfalfa, rice, and wheat D) grasses, bananas, and beans

Tryptophan is an amino acid necessary for E. coli survival and growth. E. coli contain genes coding for enzymes that synthesize tryptophan. These genes are grouped together on a segment of DNA called the tryptophan (trp) operon.