many science questions for u?

Question

Some other quest
1. If A Trait is not inherited what might cause it?
2. What Is sexual reproduction? give an example
3. What is asexual reproduction? give and example
4. What does it mean for a trait to be dominant?
5. What causes variation among humans?
6.What are some trade-offs to being tested for a genetic disease?
7. what is a clone?How are they diffrent from identical twins?
8.What does it mean for s trait to be recessive?

Please number the answer so i no

Answer 1

1. A trait may come from a mutation in the DNA.

2. Sexual Reproduction is reproduction with two parents through joining of a sperm and egg cell. Humans Reproduce by means of sexual reproduction.

3. Asexual Reproduction is reproduction with one parent. The offspring are usually identical to the parent. Some bacteria reproduce by a type of asexual reproduction called: Binary Fission.

4.If a trait is dominant that means the allele of the gene is dominant. An allele is an alternate form of a gene. Dominance means that that trait will be the one expressed.

5.Variation in humans comes from crossing over, and from the two sex cells (Sperm and Egg) being combined because the two parents have different Chromosomes that are given off creating Variation.

6.I'm not sure what you mean by trade off, but a genetic disease is a disease you can inherit from your parents. Your parents may not have the disease expressed but they could be carriers and the alleles for the disease are stored in the sex chromosomes.( X & Y)

7.A clone is an exact reproduction of an organism. Idenitcal Twins are the same organism, but they were made at the same time not by creating a whole new organism in a lab and giving it off to an organism to hold on to until birth. Identical twins will have genes and dna from two parents.

8. A recessive gene is the opposite of dominant genes, they express something but must have two recessive genes to express them, unless there is an instance where codominance takes place, like in flowers.

Answer 2

1. Phenotypically, it would mean that the trait is, if it is not expressed recessive. Or it means that the individual did not receive that particular allele from a parent.

2. Sexual reproduction always involves meiosis and requires two different types of gametes from two parental individuals. For instance, the egg from a mother and the sperm from a father combine, each giving the offspring one allele for each of the genes in the genome of whatever species is mating.

3. A sexual reproduction will always be mitosis and simply involves one individual splitting into two new individuals, and each individual gets a copy of the DNA. Essentially, it produces clones. For examply, bacteria that reproduces by binary fission.

4. A dominant trait is the allele that is expressed when more than one version of that allele exists or is inherited. So if an individual inherits an allele for a spotted coat (recessive) and one for a solid coat (dominant), the solid coat will be expressed.

5. Sexual reproduction and mutations, because of the mix of alleles in the gene pool of a population.

6. Well, one you will know what the risk is when or if you decide to have children. Also, if you are tested before the genetic disease manifests itself, you can take precautions and be treated early. Consequences would be dealing with the fact that there is little you can do, and some would-be parents would have the make very crucial decisions as whether or not to have children or terminate a pregnancy. Also, sometimes some tests for certain diseases have a risk of their own to the individual or offspring.

7. A clone is an individual with an indentical copy of DNA as the original individual. Identical twins are clone, because the DNA is the exact same. The embryo splits, producing two new embryos, which will essentially be clones of the original embryo.

8. A trait that is recessive will not be expressed unless the individual inherits two copies of the recessive allele.

Answer 3

1. LOL. Lots of answers here.
a) mutation at the zygote level
b) acquired characteristic -- won't be passed on to the offspring, but it's still a trait nonetheless. For example, if you accidentally cut off your little finger, ...
c) viral lysogeny, while embryonic. That's right, you're carrying around genes from viruses.
d) chromosomal event. The symptoms of Down Syndrome might be considered traits, but they aren't inherited in the usual way.

2. Combining of unalike haploid gametes to form a diploid zygote. In animals, that's combining of a sperm cell with an ovum to form the zygote.

3. Asexual reproduction is a catch-all for any reproduction that doesn't require the fusing of gametes! It includes binary fission cell division (bacteria), mitotic cell division (protists), budding (some cnidarians), vegetative reproduction (your spider plants!)

4. The trait is the expression of a dominant allele; the trait will be expressed if the individual is homozygous with dominant alleles for a trait, or heterozygous with one dominant allele and one recessive allele.

5. The usual:
Mutation, viral lysogeny, chromosomal events introduce new alleles and even new genes.
Isolation / genetic drift may weed out a few alleles.
Selection may or may not weed out obviously unsuitable allele combinations and even a few alleles themselves.
Gene flow (formerly migration) can bring new alleles into a semi-isolated population.

6. The plus is: after you're tested, you know, and can get treated for a treatable condition, or make an informed decision to have children.
The minuses are: your health insurance company now charges you more or drops you, and you may decide not to have children on the basis of the information you found out about your genes.

7. A clone is an individual that is genetically identical to another individual. An identical twin is an example of a clone, so "identical twin" is a subset of "clone." Got it?

8. It means that for the trait to be expressed, the individual must be homozygous for it (and it must follow classical inheritance, LOL).

Answer 4

1.- Mutation.
2.- Producing offspring by means of two gametes (one female and one male) that are a result of mythosis. Example, mammalian, avian, fish reproduction.
3.- Producing offspring with only one parent. Example, binary fision in bacteria.
4.- That it is the one most present in the population, because it presents itself in homocigous or heterocigous state.
5.- Humans have a lot of variation because all their characteristics (except blood type) are poligenic, they involve more than two alleles. For example, skin colour involves 4 genes, eye and hair colour 14 genes. So, when their gametes undergo mythosis, only half of the characteristics pass on, and there are more combinations.
6.- Genetic tests are very expensive, in some cases like pre-natal tests they can be dangerous, and they are hard to explain. How many people truly know how parental tests are made? Also, some people undergo them without having the real need, and some don't and they needed them.
7.- A clone is an organism that has the exact same DNA as the progenitor. Twins don't have the exact same DNA, their nuclear DNA (the one in the nucleus) is identical, but their extranuclear DNA (the one in mythocondria) isn't.
8.- It is present in only a small amount of individuals in the population because it is necessary that all the alleles are present in the recessive form. Two alleles for mendelian inheritance, or more for polygenic inheritance.

Answer 5

(1) Mutation
(2) Sexual reproduction is the formation of another organism of the same species by means of joining the gametes of a parent organism of one sex with the gametes of a parent organism of another sex to form the new organism - eg. human reproduction
(3) Asexual reproduction is the formation of another organism of the same species by splitting the genetic information of the parent organism into two copies - eg. many unicellular organisms reproduce this way
(4) A trait is said to be dominant if only one copy of the allele for that trait is required to express the phenotype of that trait
(5) Variation among humans is caused by sexual reproduction and by mutations within the genome
(6) Testing for genetic disease has drawbacks - testing in utero by amniocentesis or chorionic villus sampling increases the risk of miscarriage. Testing for genetic disease in adults runs the risk of the adults having already reproduced and passed the disease on to their children.
(7) A clone is an organism made from the genetic material of a parent organism. Identical twins are a pair of organisms with the same genetic material originating in utero when a very early embryo (2 cells or 4 cells or thereabouts) splits into two embryos with identical genetic material
(8) A trait is said to be recessive if it requires both loci for the gene to have copies of the alleles of the trait for the phenotype to be expressed

Answer 6

make a HUGE volcano. then placed lego figures. make a concotion of vinegar and baking soda. then CA-BOOM! lol or seek approximately tsunamis. did u recognise that tsunamis within the north and south poles freeze once they hit the air? it's for the reason that the currents within the water are fairly above freezing, and the air is far underneath freezing. simply study the ocean. or do icicle carbon courting. its lovely cool. its like they take a middle pattern from the icicle, and it inform scientists how the earth was once hundreds (even thousands) of years in the past.