Chapter 6.2-Patterns of inheritance

Question 1

What is meant by an organisms genotype?

Answer 1

genetic makeup of an organism

Question 2

What is mean by an organisms phenotype?

Answer 2

visible characteristics of an organism

Question 3

What is a mutagen?

Answer 3

agent that causes/increases the chances of a mutation.

Question 4

What are examples of chemical, physical and biological mutagens?

Answer 4

Chemical:
-benzopyrene
-mustard gas
Physical:
-UV light
-gamma rays
Biological mutagens:
-some viruses 
-food contaminants

Question 5

What happens hewn chromosome mutation occurs which results in a deletion?

Answer 5

part of the chromosome, containing genes is lost

Question 6

What happens when chromosome mutation occurs which results in inversion?

Answer 6

section of a chromosome may break off, turn 180 degrees and then join again; although all the genes are still present. some may be now too far away from their regulatory nucleotide sequences to be properly expressed

Question 7

What happens when chromosome mutation occurs which results in a translocation?

Answer 7

piece of one chromosome breaks off and then becomes attached to their chromosome. This may also interfere with the regulation of the genes on the translated chromosome

Question 8

What happens when chromosome mutation happens which results in a duplication?

Answer 8

a piece of chromosome may be duplicated. Over-expression of genes can be harmful, because too many of certain proteins or gene-regulating nuclei acids may disrupt metabolism.

Question 9

What happens when chromosome mutation happens with result in non-disjuctnion?

Answer 9

one pair of chromosomes or chromatids fails to separate, leaving one gamete with an extra chromosome. Down syndrome, or trisomy is caused by non-junction

Question 10

What does aneuploidy mean?

Answer 10

the chromosome number is not an exact multiple of the haploid number for that organism. Sometimes chromosomes or chromatids fail to separate during meiosis

Question 11

How does genetic variation increase during meiosis?

Answer 11

• allele shuffling (swapping of alleles between non-sister chromatids) during crossing over in prophase
• independent assortment of chromosomes in metaphase/anaphase 1
• independent assortment of chromatids during metaphase/anaphase 2

Question 12

Some phenotypic variation is caused by the environment and not passed on through genes? What are some examples?

Answer 12

• regional dialect

- loosing a limb or digit, or having a scar

Question 13

Name variation caused by the environment interacting with genes (in plants)?

Answer 13

if plants are held in a a dim room, soil in which contains little magnesium.
-plant does not develop enough chlorophyll and therefore the want is described as being chlorotic

Question 14

What is an allele?

Answer 14

version of a gene