__________________ charcters show many degrees of variation because they result from the additive effects of several ____________.

Many human conditions are complex because they are influenced both by ___________ and by ___________.

If two genes cross oveer 35 percent of the time, they will be ____________ map units apart on a chromosome map.

Why is hemophillia carried by females and yet rarley expressed in females?

what is a gene mutation?

I can only answer some of your questions.

Human conditions are influenced both by environment and heredity.

Hemophilia is carried on the X chromosome. Females are very likely to have a gene for normal blood clotting on their other X chromosome, but males have no such gene on the Y. Thus females can be carriers, but males who have the gene always exhibit it in their phenotype.

http://en.wikipedia.org/wiki/Haemophilia#Genetics

Gene mutation is a random change in a gene.

http://www.brooklyn.cuny.edu/bc/ahp/BioInfo/MUT/Mut.Definition.html

In the future, for some of these you can find the information you desire more quickly, if you use appropriate key words to do your own search. Also see http://hanlib.sou.edu/searchtools/.

I hope this helps.

To answer these questions, we need to understand some basic concepts related to genetics. Let's break it down step by step:

1. The first question is about the variation in characters and the factors that contribute to it. Characters can show many degrees of variation because they result from the additive effects of several genes. These genes contribute to the expression of specific traits, and the combination of different alleles (alternative forms of genes) can lead to a range of variations.

To understand how to get this answer, you can consult a genetics textbook or reliable online resources that provide information on how genes influence traits and the concept of genetic variation.

2. The second question highlights the complexity of human conditions. Many human conditions are influenced both by genetics and environmental factors. Genetic factors refer to variations in genes that can predispose individuals to certain conditions or diseases. Environmental factors include things like diet, lifestyle, exposure to toxins, and other external influences that can impact the expression of certain traits.

To find this answer, you can explore scientific literature, genetic studies, or consult credible sources discussing the influence of genetics and environmental factors on human conditions.

3. The third question is about genetic linkage and distance on a chromosome map. When two genes cross over (undergo recombination) 35% of the time, they are said to be 35 map units apart on a chromosome map. The percentage of crossover events is used as a measure of the distance between genes on a chromosome. The higher the percentage of crossovers, the greater the distance between genes.

To determine this answer, you can refer to genetic mapping studies, genetic mapping techniques, or resources explaining the concept of genetic linkage.

4. The fourth question relates to hemophilia, a genetic disorder that is carried by females but rarely expressed in females. Hemophilia is an X-linked recessive disorder, meaning the gene responsible for it is located on the X chromosome. Females have two X chromosomes, while males have one X and one Y chromosome. In females, the presence of two X chromosomes creates a protective effect. Even if one X chromosome carries the hemophilia gene, the other X chromosome can often compensate for it, resulting in a milder or asymptomatic form of the disorder. Males, who have only one X chromosome, are more likely to express the disorder if they inherit the hemophilia gene.

For a detailed understanding, you can refer to medical genetics textbooks, articles on X-linked disorders, or consult medical professionals.

5. Finally, a gene mutation refers to a permanent alteration in the DNA sequence of a gene. This alteration can result in a change in the gene's function or the protein it codes for. Gene mutations can occur naturally as a result of errors during DNA replication or due to exposure to external factors such as radiation, chemicals, or certain drugs. Mutations can lead to genetic disorders, changes in physical characteristics, or contribute to the evolution of species.

To get a comprehensive answer, you can explore genetics resources, genetics textbooks, or consult reputable sources explaining gene mutation and its implications.

Remember, understanding these concepts thoroughly may require further research and studying from reliable sources.