Genetics?

Why some children look more like one parent than the other?

Aim

To investigate why some children look more like their mothers and some like their fathers. Also to investigate the sub-topics that relate to this question.

Research

Where are genes located

Genes are located/stored inside chromosomes. A chromosome has a single strand of a long DNA helix. it is on this strand that the genes are attached onto. the area where a particular gene is located is called the locus.

Do sons look more like their mothers and daughters like their fathers?

A child has a 50% chance of inheriting DNA information from their mothers and their fathers. But, as the X chromosome is slightly bigger than the Y, which has more DNA means that there is a slight chance there is more DNA received from the mother than the father. That is why some sons look more like their mother. But there isn't scientific information to support that daughters look more like their fathers.

What role do chromosomes play in genetics?

DNA molecules are tightly packed around proteins called “histones” this is what makes up a chromosome. Human beings have 23 pairs of chromosomes in every cell which is 46 chromosomes in total. Sex chromosomes determine whether you’re a boy (XY) or a girl (XX) all other chromosomes are called autosomes. Chromosomes contain genes, Chromosome 1 (the largest chromosome) contains 8000 genes and chromosome 21 (the smallest chromosome) contains 300 genes. DNA that contains your genes are stored in cells in a structure called the nucleus.

How are genes passed on?

Genes are passed through sexual fertilization, requiring the meeting of the sperm with the egg, and the combining of the DNA from both.

What does a gene look like?

A gene has several parts, most genes include protein making instructions broken up into shorter sections called “exons” which are distributed with “introns” longer sections of DNA called “extra” or “nonsense”. Genes have regulating sequences which help determine where, when and in what amount proteins are made. A schematic drawing of a gene includes things that look like ribbon divided into segments, however this is different to the reality of what a gene looks like as genes look like any other piece of DNA.
Big image

What is a genetic cross?

A genetic cross involves controlled breeding of a phenotypically dominate person and a phenotypically recessive person. This determines the similarity (zygosity) of the previous thing by analysing proportions of offspring phenotypes. A phenotype is a set of observable characteristics of an individual resulting from the interaction of its genotype with the environment. Zygosity can either be heterozygous two genes that are different or homozygous two of the same genes that control a particular trait.

Do children look like other family members?

Yes. First cousins are 25% half- identical with the kid and this 25% comes out from the grandparents. The father or mother share 100% of their parents DNA and the brothers and sisters of father or mother share the same amount of DNA from their parents and their kids get 50% of their DNA which is similar to the grandparents DNA. Therefore first cousins have a bit of similarity in DNA.

Do children inherit more genetic information from their fathers or mothers?

A child inherits half their DNA from each parent, while each parent passes half their DNA to each child. This is occurring because of each egg and sperm just have 23 chromosomes each. It is the half of total 46 chromosomes.

Conclusion

In conclusion it was found that the answer to the question “why do some children look more like their mothers and others look more like their fathers” was that it has to do with the fact that the two copies of each gene recieved from parents aren’t necessarily identical. There can be different versions of the same gene. It’s the combination of the two versions of the gene that is inherited that decides what a child looks like and those genes can be inherited from the child's parents or anything in between.

Bibliography

BY ATHIRA JEWEL AND JESSICA