Genetics

Question 1

Define a mutation

Answer 1

Any change in DNA that may result in a new phenotype

Question 2

Explain where germ cell mutation occurs and if it affects the organism or the offspring (and why that is)

Answer 2

Occurs in the gametes. Doesn’t affect organism but is passed to offspring because it’s on the sex cells which a child gets one from mom and one from dad.

Question 3

Germ cell mutations provide the __________ on which ____________________ acts

Answer 3

Variation, natural selection

Question 4

Explain where somatic cell mutation occurs and if it affects the organism or the offspring (why)

Answer 4

Occurs in the body cells, is passed to daughter cells by mitosis (affects organism)

Question 5

List the 4 types of chromosomal mutations

Answer 5

Deletion, inversion, translocation, nondisjunction

Question 6

Define deletion mutation and be able to draw picture of it

Answer 6

A piece of chromosome is deleted PICTURE

Question 7

Define inversion mutation and draw picture

Answer 7

A section of chromosome breaks off and reattaches in the opposite direction PICTURE

Question 8

Define translocation mutation and draw picture

Answer 8

A section breaks from one chromosome and attaches to another PICTURE

Question 9

Define nondisjunction mutation and be able to draw a picture of it

Answer 9

When chromosome pairs fail to separate during meiosis PICTURE

Question 10

Describe difference in origin from monosomy and trisomy in nondisjunction

Answer 10

Mono: when a zygote has only one chromosome of a pair (turners syndrome)
Tri: when a zygote has 3 of a particular chromosome (downs)

Question 11

Define gene mutations

Answer 11

May involve a single nitrogen base or a larger segment of a gene

Question 12

Differentiate between chromosome mutations and gene mutations

Answer 12

Chromosome only has the mutation of one specific chromosome, while gene mutations involve nitrogen bases or larger segments of genes.

Question 13

List the two types of gene mutations and draw picture

Answer 13

Point mutation

Frame shift mutation

PICTURES

Question 14

Identify and justify why which of the two types of gene mutations would lead to the largest change in the genetic code of an organism

Answer 14

The frame shift mutation because (insert pictures of both frame and point mutations) the frame shift changes every single amino acid after the first 3 while the point only changes one amino acid in the whole thing

Question 15

Define mutagen

Answer 15

Factors that cause mutations

Question 16

List the five examples of mutagens listed in class

Answer 16

Sunlight, cig tar, asbestos, radiation, some viruses

Question 17

Explain the purpose of the Ames test

Answer 17

It’s a test used to identify mutagens

Question 18

Describe the purpose of a pedigree

Answer 18

Too show how a trait is inherited over several generations

Question 19

Define carrier

Answer 19

Someone who is heterozygous. They don’t show the recessive trait but they can pass it to their offspring

Question 20

Define single allele trait

Answer 20

Homozygous recessive (2 rec alleles to show trait), codominant,

Question 21

Explain the difference between a dominant and a recessive trait

Answer 21

The dominant trait always is the one that shows in the phenotype if it is present in the genotype.
The recessive trait only shows up if you have both recessive alleles in genotype

Question 22

Define codominant allele

Answer 22

If you are heterozygous for this genotype, you will express both phenotypes

Question 23

Define incomplete dominance

Answer 23

Dominant allele is not completely dominant over the recessive allele, a blending of the phenotypes is seen

Question 24

Define polygenic trait

Answer 24

Trait that is controlled by 2 or more genes (skin color, eye color, fur color in labs)

Question 25

Define multiple allele trait and identify a human trait that is multiple allele

Answer 25

3 or more alleles of the same gene code for a single trait

Blood type (ABO)

Question 26

Define sex linked trait

Answer 26

Genes for these traits are found on the sex chromosomes (X)

Question 27

Define sex limited trait

Answer 27

Autosomal-not found on X or Y chromosome

Phenotype appears only in one gender

Question 28

Define sex influenced trait

Answer 28

Traits that are influenced by the presence of male or female hormones (baldness)

Question 29

Define genetic screening

Answer 29

Examination of a persons genetic makeup (karyotype, amniocentesis, fetoscopy)

Question 30

Identify and describe the 5 tests used for genetic screening

Answer 30

Karyotype- analyze chromosome images
Amniocentesis- test amniotic fluid for chromosomal abnormalities
Fetoscopy- scope inserted into uterus to view fetus
Ultra sound- noninvasive view of fetus
Chorionic villi sampling- test villi from placenta

Question 31

Define evolution

Answer 31

The change in the allelic frequency of a gene in a population over time

Question 32

Identify the two scientists and what they contributed to the modern theory of evolution

Answer 32

Darwins “survival of the fittest” through natural selection explains species variation, but not individual variation

Mendel use of alleles and inheritance explain individual variation not species variation

Together thy cover everything

Question 33

Explain the difference between scientific law and scientific theory

Answer 33

A scientific law is a statement based on repeated experimental observations that describes some aspect of the universe. (Doesn’t explain why)

A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment. (Explains why)

Question 34

Define polymorphisms and list examples

Answer 34

Phenotypic differences within a species.

Butterfly colors, skin color, beak sizes

Question 35

Differentiate between variation in chromosomes, protein structure, and nucleotide sequence, and know which lab method is used for each

Answer 35

Chromosomes: banding pattern differences of chromosomes

Protein structure: use gel electrophoresis to move proteins based on size

Nucleotide: DNA sequencing is used to identify changes in nucleotides