<span>B. Inherited behaviors that allow animals to survive and reproduce will be spread throughout the population and can evolve by natural selection.</span>
Answer:
a. heart development.
Explanation:
As the third week of fetal development starts, the process of formation of blood vessels begins. Also, the splanchnic mesoderm in the head end of the embryo forms heart on days 18 and 19. Since it develops heart, this part of the mesodermal cells is called the cardiogenic area. The underlying endoderm sends the induction signals to these mesodermal cells to form a pair of endocardial tubes that gradually develop into a single primitive heart tube.
This primitive heart begins to beat by the end of the third week of development. Therefore, any drug that affects fetal development during the first 20 days of the pregnancy might affect the development of the heart.
The right option is; c. biomes
Savanna is considered a transitional biome because it is intermediate between two biomes.
A savanna is a tropical grassland ecosystem that is characterized by widely spaced scattered trees. Savanna is an extensive plain that is regarded as a transitional biome because it is intermediate between moisture equator forests and tropical deserts. It covers about 20% of the earth’ surface. Savanna has seasonal water availability and during the dry season, there are strong evaporation which makes the trees such as baobab to shed their leaves while bushes and grasses wither.
Answer: An independent variable, sometimes called an experimental or predictor variable, is a variable that is being manipulated in an experiment in order to observe the effect on a dependent variable, sometimes called an outcome variable.
Explanation: Example: What is a good outcome variable for deciding whether cancer treatment in a country has been improving?
A first thought might be "number of deaths in the country from cancer in one year." But number of deaths might increase simply because the population is increasing. Or it might go down if cancer incidence is decreasing. "Percent of the population that dies of cancer in one year" would take care of the first problem, but not the second.
This example makes the point that a rate is often a better measure than a count.
The answer is A. because the muscles pull the bones since they are attached.
