Midterm Flashcards
How many chromosomes are in a “normal” human karyotype
46
What’s produced during transcription?
Transcription is the process of making a strand of MRNA from a gene on a DNA molecule. (Occurs in nucleus)
Base pair rules…?
A=T
C=G
(For RNA, A=U)
What can a karyotype show?
Extra or missing chromosomes, and the gender (large changes)
(XY or XX)
What are the sex chromosomes of a male?
Female? Male = XY, female = XX
What is the gene pool?
Hypothetical spot where all genes for a trait in a
population are.
What sex chromosomes does a mother give to her child?
Mother can only give an X chromosome
What is phenotype?
The physical characteristic that an organism has due to genes. Ex. Red flower
How would Down syndrome be detected on a karyotype?
Extra chromosome (triosmy) #21
What’s the difference between a point mutation and a chromosomal mutation?
Point mutation only affects one nucleotide in a sequence of DNA. A chromosomal mutation is when there is an extra (trisomy) or missing (monosomy) due to non-disjunction (failure of chromosomes to separate during meiosis)
Most sex linked genes are located where?
On the X chromosome
Why is colorblindness more common in males than in females?
Since males are XY and only have one X chromosome, they only need to have one affected allele
to have the trait. Since females have two X’s, they will need to have both alleles
to have said trait.
What is “DNA Fingerprinting” and what is it based on? Also called gel electrophoresis.
It’s based on the idea that no two people (except identical twins) have the same
DNA; so no two people will have the same DNA “fingerprint”.
What restriction enzymes and what do they do?
Restriction enzymes are used in
DNA fingerprinting. They cut strands of DNA at a particular sequence that they
recognize.
The 2 main sources of genetic variation are?
Mutations and sex
What is genotype?
The alleles (portions of a gene) of an individual. Ex. Rr
What is gel electrophoresis and what can it be used to determine?
It can be used to determine who committed a crime, paternity tests, if organisms’ DNA is similar (relatedness), to check for a certain gene on a strand of DNA, etc.
What is haploid and diploid?
Haploid is one copy of each chromosome (n), diploid is two of each chromosome (2n)
What are codominance, incomplete dominance, and polygenic traits?
Codominance = both traits are expressed (ex. Red and white speckled flower) Incomplete dominance = heterozygous is in between both homozygous traits (RR = red, Rr is pink, and rr is white)
What is a pedigree and what can it be used for?
Can be used to tell how a trait is inherited, what people have a trait, etc.
What is homozygous dominant, homozygous recessive, and heterozygous?
RR, rr, Rr
What are the similarities and differences between DNA and RNA
Similarities = both have phosphate and bases cytosine, guanine, and adenine Differences = DNA has sugar deoxyribose/ RNA has sugar ribose, DNA is double
stranded/ RNA is single stranded, DNA has thymine/RNA has
uracil
What is the difference between a dominant and recessive allele?
Dominant is usually expressed more than recessive and is written with a capital letter and recessive is written lowercase.
What book did Darwin write?
On the Origin of Species (by Means of Natural Selection)
What is the advantage of a polygenic trait over a single gene trait?
Polygenic
trait results in higher variation in a population. This will give the population a
better chance of survival if adverse conditions develop in the environment.
What sex chromosomes does a father give to his child?
Male has a 50% chance of making sperm that contain an X chromosome, 50% for a Y sperm. All females’ eggs will contain one X chromosome.
