When writing a research paper, look for the most credible sources. Science doesn’t show bias, but we humans tend to show bias. There are sites and articles that provide facts without proper scientific evidence. Avoid using information from such sites. You must be able to identify reliable sites so the data in your paper is credible. Use sources that end in .gov (government sites), such as CDC. gov. They are reliable sources. You can also use sites ending in .edu. They can be deemed trustworthy, but sometimes the information is written by students rather than scientists. Always find out who the author of the article is before proceeding. Some .org and .com sites are credible, but you need to analyze the contents to verify their authenticity. As you review a source, always try to answer these questions:

Who authored the article?
Is this person an expert in genetic diversity or koalas?
What is the purpose of the article?
Does the article state facts that scientists can prove with evidence?
Are there opinions in the article?
How old is the article?
Do other credible sources support the statements in the article?
Find some credible websites, and note the information they contain. Write down two or three sources that you’ll use for your paper, and cite them using MLA (Modern Language Association)

the generally accepted parts of modern cell theory include: all known living things are made up of one or more cells. all living cells arise from pre-existing cells by division. the cell is the fundamental unit of structure and function in all living organisms.

that scientist would be robert hooke

an individual’s sex (i.e., whether they are a male or female) is determined by the sex chromosomes. most people have two sex chromosomes, one that is inherited from their mother and one that is inherited from their father. typically, females have two x chromosomes (xx) and males have one x chromosome and one y chromosome (xy). conditions caused by changes (“mutations”) in genes located on the x chromosome are considered x-linked.

x-linked recessive inheritance

most x-linked conditions are recessive. this means that in a person with two x chromosomes (most females), both copies of a gene (i.e., one on each x chromosome) must have a change or mutation whereas in a person with one x chromosome (most males), only one copy of a gene must have a mutation. a female with a mutation in one copy of a gene on the x chromosome is said to be a “carrier” for an x-linked condition. a male with a mutation in a gene on the x chromosome is typically affected with the condition. because females have two copies of the x chromosome and males have only one x chromosome, x-linked recessive diseases are more common among males than females. however, x-linked recessive diseases can occur in both males and females.

for x-linked recessive disorders, an unaffected carrier mother who has a mutation in a gene on the x chromosome can transmit either the x chromosome with this mutation or a “normal” x chromosome to her children. if the father is unaffected, none of her daughters will be affected and all of her daughters will be unaffected—since they will inherit at least one normal x chromosome from their father. however, each daughter will have a 50% chance of being an unaffected carrier like her mother and a 50% chance of both x chromosomes being normal.