Albert, a student researcher, varies the amount of food given to rats in an experiment to measure the effect on their learning behavior. In albert's study, the amount of food given is the independent variable.
An independent variable is under the control of the experimenter. Independent variable does not depend on the other variables involved in the experiment. Since the amount of food is varied, it is not depending on other variables like size of mice, weight, etc.
Answer:
The correct answer would be zygote...blastocyst...embryo...fetus.
The fertilization of sperm and egg results in the formation of zygote. It receives genetic material from a male as well as a female parent.
It divides with the help of mitotic divisions and results in the formation of 2, 4, 8, and 16 celled stages.
It results in the formation of the hollow spherical ball of cells termed as a blastocyst. The cells are distributed to form the outer layer termed trophoblast and inner cell mass which gives rise to the embryo.
Trophoblast help in the implantation of the blastocyst into the uterine wall.
The cells of the embryo undergo organogenesis during different organs such as heart, brain, lungs et cetera are formed.
In humans, almost 9 weeks after the fertilization the developing embryo is considered a fetus.
The fetus development continues until birth.
Answer: B - People with two copies of the mutated gene have sickle-cell anemia. People with one copy of the mutated gene have both healthy and misshapen red blood cells and are carriers of the disease.
Explanation:
Co-dominance is when both the alleles of a gene in a heterozygote show. In the case of sickle cell anemia (since it is a co-dominant trait) even if the person only has one sickle cell allele, symptoms of sickle cell will still show up in that person. That's why the person in this example has both misshapen and healthy red blood cells.
Answer:
Most of the heavy metals on earth came from outer space from supernovas
This occurs when stars die
Explanation:
Visit Ted-Ed on You Tube
Type in the origins of gold and take notes
Happy to help
