Can anyone help me with these Biology questions? (8th Grade)?

1. What is a mutation?





a. any change that is harmful to an organism


b. any change in a gene or chromosome


c. any change that is helpful to an organism


d. any change in the phenotype of a cell





2. A mutation is harmful to an organism if it __________





a. changes the DNA of the organism.


b. changes the phenotype of the organism.


c. reduces the organism’s chances for survival and reproduction.


d. makes the organism better able to avoid predators.





3. How does a geneticist use pedigrees?





a. to create genetic crosses


b. to replicate identical strings of DNA


c. to prove that sex-linked traits are caused by codominant alleles


d. to trace the inheritance of traits in humans





4. What is a pedigree?





a. a chart that tracks which members of a family have a particular trait


b. a geneticist who studies the inheritance of traits in humans


c. a picture of all of the chromosomes in a cell


d. an allele passed from parent to child on a sex chromosome





1st person to answer them all right gets 10 point

Can anyone help me with these Biology questions? (8th Grade)?
1-b


In biology, mutations are changes to the nucleotide sequence of the genetic material of an organism


2-c


deleterious (bad) mutations are reduced in frequency in the gene pool by natural selection,





3-d


A pedigree chart is a chart that tells one all of the known phenotypes for an organism and its ancestors


4-a


see above
Reply:#1-B


#2-C


#3-D


#4-A
Reply:1. b


2. c


3. d


4. a
Reply:1. b


2. b


3. a


4. a