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cells and genetics
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Question | Answer |
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How can you tell a karyotype is human? | A human karyotype will have 23 pairs(46 chromosomes) |
How can you tell if a karyotype is male or female? | a female karyotype will have two long chromosomes(xx) for the last pair, and a male karyotype will have a long and a short chromosome(xy) for the last pair. |
How are karyotypes made? | they are made by taking a photograph of the chromosomes in a nucleus, cutting out each chromosome, and reorganizing the into pairs. |
How are karyotypes organized? | they are organized by length(longest to shortest), banding pattern, and where the pinch is. |
How do karyotypes of different organsisms differ? | different organisms will have different length karyotypes, because they all have different numbers of chromosomes. |
Why is there a 50 percent chance any pregnancy will result in a boy or a girl? | every egg cell has 1 x cell. For every two sperm made, one has an x chromosome and one has a y chromosome. so 50% of the sperm have an x and the other 50% have a y.a boy is xy and a girl is xx so whichever 1 of every two sperm gets the egg, decides gender |
How many chromosomes does a human body cell have? | 46 chromosomes. there are 22 pairs and then an xx or xy. |
How many chromosomes does a human gamete have? | 23 chromosomes. 22 different ones, and then an x or a y. |
What is a zygote? | A zygote is the first cell of a baby. |
How are identical twins formed? | one fertilized egg cel splits into 2 zygotes for an unknown reason. |
How are fraternal twins formed? | fraternal twins are created when two different egg cells are fertilized. |
Why can a child not look exactly like one parent? | the kid gets half of their genetic traits from one parent and half from the other, they don't get all from one so they can't be exactly like one. |
Why are twin studies so helpful when trying to figure out if a trait is genetic, environmental or multifactoral? | if the twins have a trait the same, you know it is genetic. If they have a trait different, you know it is environmental. If they have a trait similar, you know it's multifactoral. |
What is the relationship between ribosomes and chromosomes? | Ribosomes make al the proteins, so because chromosomes are made of genes, genes are made of dna, and dna is protein, ribosomes make chromosomes. |
How is a geenoid gene gene like hair form(I or i) different from other traits like eyebrows(F1 or F2) and hair length(J1 or J2) | The capital letter(I) is the dominant gene, and the lowercase letter(i) is recessive. So unless you have two of the recessive, you don't even know you have it because the dominant gene takes over. with(F1) there are no doms. you just combine. |
Examples of genetic traits. | blood type, eye color, natural hairline |
examples of environmental traits. | clothing preferance, preferance of a tv show, favorite soda brand. |
Why are traits genetic or environmental? | genetic b/c it is decided by your chromosomes. you have a gene in a chromosome inherited from parents for eye color. environmental b/c you don't have a gene for it, the trait is completely decided by your environment. |
What is a multifacotral trait? | a trait that is deided by your genes and by the environment. Hair form- you might have naturally curly hair(genetic) but like the way it looks straight so you striaghten it(environmental.) |
Why is a nucleus important for cell survival? | The nucleus holds chromosomes which are the plans for creating new chromosomes in cell division. |
What happens to to the chromosomes of a body cell making sex cells? | each new gamete will get half of the chromosomes from the body cell. |
What happens to to the chromosomes of a body cellin cell division? | each new body cell gets the same number of chromosomes as the original body cell. |
Why is it important for body cells to divide? | When cells die, it is important they can be replaced and we need to grow(new cells) |
Compare body and sex cell division. | both create two new cells. |
contrast body and sex cell division. | body gets all chromosomes, sex gets half. |