Sierra College Department of Biological Sciences

Discover the Biological Sciences

The introductory information for this site has been contributed as a joint assignment by students in Bio. Sci. 10.

Genetics - Heredity

By: Janae Conley

1) Biological field or sub-topic chosen:

Genetics, sub topic- heredity

2) Define field or sub-topic:

Genes are always passed down from generation to generation. Things that are hereditary aren’t always going to be the case with everyone. The genes will not always be dominant.

3) Describe in more detail the breath and depth of what could be studied or learned within this topic:

There are many things that could be studied within genetics. The genes for certain traits are passed down in families from parents to children. This has been known for thousands of years… even in biblical times and has allowed farmers to breed better crops and animals. For example, parents with black hair will likely give birth to children with black hair, just as with big noses will have kids with big noses. Once in awhile though, this doesn’t work and parents with black hair will give birth to a blond. This can be explained by the principle of segregation. There’s three parts to this principle.
1. Hereditary traits are determined by specific genes.
2. Individuals carry two genes for each trait, one from the mother’s egg and one from the father’s sperm.
3. When an individual reproduces the two genes split up (segregate) and end up in separate gametes.

4) Focusing on one major concept, principle, or group of organisms (as appropriate within the topic), describe its importance, relationships, functional aspects, or otherwise explain it in more depth as seems important to you and (potentially) the others in class:

The major concept that I am focusing on is Identical twins, I am an identical twin and I have always been curious of the genetics and wanting to know if the myth is true about skipping generations. There are two types of twins - identical and fraternal. To form identical twins, one fertilized egg (ovum) splits and develops two babies with exactly the same genetic information. This differs from fraternal twins, where two eggs (ova) are fertilized by two sperm and produce two genetically unique children, who are no more alike than individual siblings born at different times. Twins are slightly more likely to be female than male (50.3 per cent). Contrary to popular belief, the incidence of twins doesn't skip generations. The information I have found out about identical twins has proved my myth to be false because more the one source that I have researched said that it doesn’t necessarily skip generations.
The heredity aspect of the research I have done stated that a woman is more likely to conceive fraternal twin if she is a fraternal twin, has already had fraternal twins or has siblings that are fraternal twins. Again I was proved wrong. I am an identical twin and twins are very common in my family and my sources are right it doesn’t always skip a generations.

5) In studying and discovering more about this topic, what was the most interesting aspect, fact or some other piece of information that you have learned.

I have learned that twins don’t necessarily skip generations and I had been informed for as long as I can remember. In my family they do skip generations but that is not always the case. That was very interesting.

6) References – provide references used and at least two Web sites with additional information on this topic (or sub-topic) for anyone that would like to learn more:

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