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Big History Project
Course: Big History Project > Unit 5
Lesson 1: What Is Life? |5.0- ACTIVITY: DQ Notebook 5.0
- WATCH: Unit 5 Overview - Life
- ACTIVITY: Vocab Tracking
- WATCH: A Big History of Everything - H2
- ACTIVITY: How Closely Related Are We?
- ACTIVITY: Threshold Card — Threshold 5 Life
- WATCH: The Origin of Life
- READ: Life and Purpose
- READ: Gallery — What is Life?
- ACTIVITY: Claim Testing – What Is Life?
- Quiz: What Is Life?
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ACTIVITY: How Closely Related Are We?
Purpose
This activity will help you understand the relationship between different species, and show you how we (humans) are related to other species. The evolution of life from bacteria to humans is pretty hard to wrap your mind around, and showing connections among different species will increase your understanding.
Process
One of the amazing things about life is just how interconnected living things are. Genetic studies have helped biologists pin down the extent of these connections. In this activity you will be asked to consider what you know about these relationships.
Look at the How Closely Related Are We? Worksheet and try to match the list of organisms with the percentage of DNA shared with humans.
Once you have done this, take a look at the answer key, and see how well you did.
For Further Discussion
Some people find it surprising that chimps and zebrafish have so much DNA in common. What are some of the physical traits they share? Post your thoughts to the Questions Area below.
Want to join the conversation?
They share eyes, mouths, teeth, bones, tail-bones, rectums, spines,(8 votes)
they both have a way to move around(4 votes)
say if the mother or father has blue eyes and red hair and the daughter has brown eyes and black hair how does this happen?(2 votes)
The issue of inheritance of traits and genetics include change, combinations of genes, and random chance. Otherwise, we would all be duplicates of one parent.
As for the daughter with eye and hair color, there are various possibilities:
1. The genes for eye color and hair color possess dominance and recessiveness, so maybe both mother and father had recessive genes for brown eyes and black hair, while they may have dominant genes for blue eyes and red hair. So both parents have genes (blue+brown) for eyes, and dominant blue for eyes wins out, so the parents have blue eyes, and have genes (red+black) for hair, and the dominant red for hair wins out, so both parents have red hair. The sperm and egg only have half the genes, so the father can produce sperm with only blue-genes for eyes or only brown-genes for eyes, but not both, and the same goes for the mother producing eggs with only blue-genes or only brown-genes. Same goes for the hair genes. Therefore, the daughter may have been conceived with a (brown eyes, black hair) sperm and a (brown eyes, black hair) egg to get both (brown-brown) genes for eyes, with no dominating blue gene for the eyes, and both (black-black) genes for hair, with no dominating red gene for the hair.
2. There may not be genes for dominance-recessiveness, since it depends on the trait, but genes can blend or cross-over, so maybe the brown-eye gene was formed from parts of the eye genes from both parents, and the part for blue-eyes did not collect together, with only parts for brown eyes blending and collecting to form the daughter's genes.
3. Multiple genes cause a trait, so the daughter got a combination of two or more genes that made brown eyes, which was a different combination than the parents had.
4. Mutation ... by some random chance, a gene was not properly copied, leaving out the genes for blue eyes, or radiation randomly hit a gene changing the A nucleotide to T or something like that, changing the blue-eye gene to a brown-eye gene.
See http://en.wikipedia.org/wiki/Mendelian_inheritance and note the discussion of Punnett Squares for how recessive traits can show up in children but not in their parents.(3 votes)
They both have to eat and they can reproduce. They have eyes, noses, and mouths. They also both have digestive systems. That's about all I can think of.(3 votes)
They both produce energy(2 votes)- when a red eye female and white eyed male mix why are there no white eyed offspring(1 vote)
In genetics, the phenomenon you described is commonly known as "sex-linked inheritance" or "X-linked inheritance." It involves genes located on the sex chromosomes (X and Y chromosomes in mammals). In fruit flies, which I assume you are referring to, the gene that determines eye color is located on the X chromosome.
Red eye (wild type) is a dominant trait, while white eye is a recessive trait. The genotypes of the red-eyed female and white-eyed male fruit flies would typically be as follows:
Red-eyed female: X^R X^r (where X^R is the dominant red-eye allele, and X^r is the recessive white-eye allele)
White-eyed male: X^r Y (since males have one X and one Y chromosome)
When they mate, their offspring inherit one sex chromosome from each parent. The possible combinations are:
X^R X^r (female offspring, red-eyed carriers)
X^R Y (male offspring, red-eyed)
X^r X^r (female offspring, white-eyed)
X^r Y (male offspring, white-eyed)
As you can see, both male and female offspring can inherit the white-eye allele from their parents. However, white-eyed males are infertile and cannot produce offspring. So while you may get white-eyed female offspring from this cross, you won't see any white-eyed males in the next generation.
The gene responsible for eye color in fruit flies was one of the first to be discovered and studied in genetics. Assuming that we would be talking about fruit flies that is.(1 vote)
What do you think the primordial species was like?(1 vote)- It seems strange to share so much DNA with a zebrafish. How does that work?(1 vote)
- The issue of inheritance of traits and genetics include change, combinations of genes, and random chance. Otherwise, we would all be duplicates of one parent.
As for the daughter with eye and hair color, there are various possibilities:
1. The genes for eye color and hair color possess dominance and recessiveness, so maybe both mother and father had recessive genes for brown eyes and black hair, while they may have dominant genes for blue eyes and red hair. So both parents have genes (blue+brown) for eyes, and dominant blue for eyes wins out, so the parents have blue eyes, and have genes (red+black) for hair, and the dominant red for hair wins out, so both parents have red hair. The sperm and egg only have half the genes, so the father can produce sperm with only blue-genes for eyes or only brown-genes for eyes, but not both, and the same goes for the mother producing eggs with only blue-genes or only brown-genes. Same goes for the hair genes. Therefore, the daughter may have been conceived with a (brown eyes, black hair) sperm and a (brown eyes, black hair) egg to get both (brown-brown) genes for eyes, with no dominating blue gene for the eyes, and both (black-black) genes for hair, with no dominating red gene for the hair.
2. There may not be genes for dominance-recessiveness, since it depends on the trait, but genes can blend or cross-over, so maybe the brown-eye gene was formed from parts of the eye genes from both parents, and the part for blue-eyes did not collect together, with only parts for brown eyes blending and collecting to form the daughter's genes.
3. Multiple genes cause a trait, so the daughter got a combination of two or more genes that made brown eyes, which was a different combination than the parents had.
4. Mutation ... by some random chance, a gene was not properly copied, leaving out the genes for blue eyes, or radiation randomly hit a gene changing the A nucleotide to T or something like that, changing the blue-eye gene to a brown-eye gene.
See http://en.wikipedia.org/wiki/Mendelian_inheritance and note the discussion of Punnett Squares for how recessive traits can show up in children but not in their parents.(1 vote)
- how closely related am i to a kangaroo(1 vote)
- Both Chimpanzees and Zebrafish have eyes and ears.(1 vote)