BIOL 1P91 SLIDO Questions
A lion that is BBNn can produce a maximum of ___ different gamete for these two traits
= 2
(BN, Bn)
How many different gametes can a BbNn lion make:
2: BN and Bn
- will make four in total but only two different ones
Widow's peak is a dominant trait. A married couple are both heterozygous for widow's peak and are expecting a child. What is the probability that their child will also have widow's peak?
= 75%
(AA, Aa, Aa will be affected, aa will not be)
Red-green colour blindness is an X-linked recessive trait. A colour-blind female is expecting a child with a normal vision male. What is the probability that their child will be colour blind? (Hers = XrXr, His = XRY
= 50% chance
(XrY, Xr = will be colour blind)
(XRYr, XRYr = will not be colour blind)
(in order to have the color blind trait there needs to be only recessive (small r) traits -any dominant trait (big R) would not lead to colorblindness
- Extra: if they were having a girl, it would be 0% chance of colorblindness, chance of a boy with colorblindness is 100%
Hemophilia B is an X-linked recessive disease. Peter has hemophilia. His wife Petra does not, and knows that she is not a carrier of the mutant allele, Peter and Petra are expecting a son. What is the chance that their son will have Hemophilia?
- 0%
- 25%
- 50%
- 100%
0%
- If mom doesn't have it then she can't pass it onto the son, because only the father has it but the dad can only pass on the Y chromosomes so the son will not get it (children only receives Y chromosomes from fathers)
A man with type AB blood marries a woman with type O blood. What proportions of blood types would you expect to observe in their offspring?
= half have type A, half have type B
In some cases, a cross between curly and straight hair will produce an intermediate phenotype of wavy hair. This is an example of:
- Codominance
- Incomplete dominance
- Simple dominant/recessive relationship
- an X-linked trait
= Incomplete dominance (wavy hair is the intermediate phenotype)
Imagine a scenario in rabbits, where at least one dominant allele at both the A and B genes is required for brown pigment. Rabbits that are aa or bb will be white. You conduct a cross between an aabb rabbit and an AABb rabbit. What ratio of offspring do you expect to observe
- 100% white
- 100% brown
- 50% white, 50% brown
- 25% white, 75% brown
= 50% white, 50% brown
How many Barr bodies would be expected in mammalian cells with a chromosomal constitution of XXXXY
Answer = 3 (inactivating all but ONE)
Betty has a mitochondrial disease, while her husband Don is unaffected. Which of the following best describes the risk to their future children
- There is a risk of transmitting this disease to all children
- There is a rick of transmitting this disease to their sons
- There is a risk of transmitting this disease to their daughters
- There is no risk
There is a risk of transmitting this disease to all children = answer (but can't determine the percentage)
In Drosophila, the purple (p) and curved © genes are on the same chromosome. A fly homozygous for purple eyes and straight winges (pp + c+c+) is crossed to a fly homozygous for red eyes and cuved wings (p+p+cc). Which of the following represent recombinant chromosomes in the gametes of the F1 heterozygote?
= p+ c+ and p c
If 100 out of 1000 offspring are recombinant, then the recombination frequency is ___________ and the genes are said to be ____ mc apart.
= 10% and 10 mc apart
During what phase of the cell cycle are chromosomes replicated?
the S phase
If a cell contains 20 chromosomes in G1, it will contain 40 chromosomes at the end of S phase
FALSE - before S phase the dna is doubled, but it is still attached (it stays attached all the way through mitosis) -goes from 1 chromatid to 2 chromatids (but NOT two chromosomes)
During which phase do sister chromatids organize into a single row in the center of the cell
- Prophase
- prometaphase
- metaphase
- anaphase
- telophase
Metaphase
What is the main purpose of meiosis in animals:
- To produce a multicellular organism
- To repair damaged tissue
- To produce a zygote
- To produce a multicellular reproductive structure
- To produce gametes
- To produce gametes
In meiosis, a homologous pair of chromosomes in a bivalent will possess ____ alleles for each locus:
= Four
Bivalent: 4 chromatids in a bivalent
What process ends the multicellular haploid phase of a plant's life cycle: (so basically which process going from haploid to diploid)
- Meiosis
- Synapsis
- Mitosis
- Fertilization
Fertilization (haploid goes into haploid to make a diploid, needs fertilization)
Avery, MacLeod, and McCarty extended Griffith's experiments by showing that the "transformation principle" was inactivated by:
DNase
What identifies the 3' end of a DNA strand:
- A free -OH group on the sugar
- A free phosphate group on the sugar
- A free -OH group on the base
- A guanine base
A free -OH group on the sugar - because it is on the sugar backbone
If a species has 22% guanine in its genome, it would be expected to have ____% adenine in its genome.
- 28%: amount of guanine equal the amount of cytosine, means that the other 50% is A and T (would be 28%)
After transferring bacteria from 15N (heavy) media to 14N (light) media, what did Meselson and Stahl observe after TWO rounds of replication to support the semi-conservative model?
- One intermediate weight band
- One heavy band
- Two bands: one heavy, one light (heavy+light = intermediate)
- Two bands: one intermediate, one light
Two bands: one intermediate, one light
How many replication forks are produced at each origin of replication?
Two
What protein synthesizes DNA?
DNA polymerase
Which of the following is the most likely consequences of a deficiency of DNA ligase:
- Lack of a replication fork
- Lack of a replication bubble
- Failure to add nucleotides to the 3' end of a DNA molecule
- Failure of DNA fragments to link into a single continuous strand
Failure of DNA fragments to link into a single continuous strand
A repeating DNA sequence at the end of chromosomes that identifies and help protects the chromosomes ends is a:
- Telomerase
- Telomere
- Primase
- primer
Telomere
What is the promoter region?
- A region of RNA that binds to RNA polymerase and initiates transcription
- A region of DNA where RNA polymerase terminates transcription
- A region of RNA that is important for transcription
- A region of DNA where RNA polymerase binds and initiates transcription
- A region of DNA where RNA polymerase binds and initiates transcription
spliceosomes are composed of:
- mRNA
- rRNA
- tRNA
- snRNPs
- DNA
- snRNPs
Exons vs. Introns
Exons: the RNA sequences found in the mature mRNA (get joined together)
Introns: intervening untranslated sequences (get removed)
What is AUG
- the START codon
- where translation should start
The start codon defines the ______ _______ of an mRNA
The start codon defines the READING FRAME of an mRNA
State the functions of these components of the translation machinery:
mRNA: made by transcription
tRNA: important for anticodon and the acceptor arm
Ribosome: the enzyme that carries out translation
T/F, cells spend 10% of their energy on translation
FALSE, they spend 90%
Anticodon is the term applied to:
- The part of the tRNA that interacts with the codon
- The part of the tRNA that binds to an amino acid
- The concept that multiple codons sometimes code for a single amino acid
- A three-nucleotide stretch that codes for "stop"
The part of the tRNA that interacts with the codon
Which of the following involves moving a peptidyl-tRNA from the A site to the P site
- Initiation of translation (process of making RNA)
- Elongation of translation
- Termination of translation
- Initiation of transcription
- Transcription elongation
- Elongation of translation (hasn't been terminated yet)
- Which is NOT a compound of biological membranes:
- Phospholipids
- Glycoproteins
- Integral proteins
- Carbohydrates
- Nucleic acids
- Nucleic acids (are part of RNA and DNA not membrane)
All of the following statements about membrane fluidity are true EXCEPT:
- Shorter fatty acids tails increase membrane fluidity
- Saturated fatty acid tails make the membrane more fluid
- Membrane fluidity is affected by the presence of double-bonds in the fatty acid tails
- At high temperatures, cholesterol makes the membrane less fluid
Saturated fatty acid tails make the membrane more fluid
- Why is FE+ not able to move directly through the membrane:
• It is amphipathic
• It is nonpolar
• It is too large
• It carries a charge
• It does not contain carbon
It carries a charge (fully positive or fully negative molecules can't go through)
0.9% NaCl solution is isotonic to red blood cells. If a red blood cell is placed in 4% NACl, what will occur? - think of solute concentration, which way the water will move
- Cell lysis
- Crenation
- Turgor pressure
- Plasmolysis
- nothing
Crenation - water will move out of the cell and into the higher concentration, crenation = cell shrinkage
What type of transport protein can move two or more molecules in opposite directions?
- Antiporter