Last test
What is a major difference between mitosis and meiosis?
Mitosis produces diploid body cells whereas meiosis produces haploid sex cells .
Why is meiosis increasing the genetic variability of the next generation?
Mixes the chromosomes of the father and mother, crossing over in the proface
What is a viroid?
Most primitive virus that only effects plants
Are chromosomes always and easy to see inside most of the cells?
No only during cell division
What is junk DNA?............................... What is another or older name for junk DNA? ...............
Non protein coding DNA, Introns
Give 2 examples where PCR changed previous scientific concepts! -- about the speed of evolution: a comparison of DNA sequences in living African elephant and extinct Mammoth showed .................. This implies ........................ --- about our species: a comparison of DNA sequences in living Homo sapiens and extinct H. neanderthaliensis showed ......................... This implies .......................
evolution, high speed adaption, high sequence similarity, 3 human species on the planet
Some human traits are also following simple dominant/recessive outlines. Which allele for the human hair is recessive, (a) curly or (b) straight?
b
When we expose chromosomes to DNA stains we find that (a) the entire chromosome is stained equally or (b) that there are bands of intense staining and less intense staining.
b
What is the wild-type phenotype for human hair color?
black
If you cross a white and a black mouse what color would be the F1?................We call this type of inheritance.........
black, incomplete dominance
At the same time that Mendel worked on peas, Charles Darwin published his work on the "Origin of Species". What was his concept about inheritance?
blending hypothesis
What is the wild-type phenotype for human eye color?
brown
How is the plant cancer Crown Gall disease induced?
by bio-bacteria
Which cells divide rapidly and uncontrolled?
cancer cells
The appearance of cancer is related to the mutation of genes (proto-oncognes) that affect which cellular process?
cell division
How does senescence or aging relate to cell divisions? Aging is defined as the stage where.......................
cell division stops
While people believed before him that life forms could spontaneously generate from dust. Spallanzani was the first to see and recognize............. in........ cells..
cell division, egg
True or false? Densely packaged DNA stretches are especially active in gene expression!
false
Virus infections always kill the host cell. True or False? Explain your answer!
false because we have lysogenic cycle that kill them right away
Bacteria divide by a simple mechanism called .............The daughter cells are genetically ................of their parent cell.
fission, identical
. Chromosomes have heterochromatin vs euchromatin regions which reflect a different degree of DNA...........
folding density
The chromosome theory of inheritance was not accepted until Alfred Blakeslee studied the inheritance in Datura plants he found a match between the shape of the chromosomes number 13 and the shape of.......
fruit
What is the mechanism by which animal cells undergo cleavage?
furrow cleavage
Why do we encounter more virus epidemics in the last 50 years than in the times before that?
globalization
What is a codon?
group of 3 mRNA bases
What did we learn about cell division of animal cells when growing cells in culture?
growth factors
How can you get plant stem cells (callus) to produce a root organ?
growth hormone
In the anaphase the mitotic spindle pulls the chromosomes apart and divides them equally between the prospective daughter cells. What kind of chromosomes is actually moved into the two halves of the cell?
half chromosome
There are two methods to separate the two stands of DNA. First you can separate them by .......and second cells use......... to do the same job.
heating, helicase
Which odd species seems to have the most most junk DNA on planet earth?
human
In comparison with bacterial and plant cells, animal cells lack a .....................(name organelle) and therefore have a way of cell division that is called..............
cell wall, cleavage
Cytokinesis = the division of ........... ; mitosis = the divison of ..........
cells, nuclei
What happens during the prophase of mitosis?
chromosomes become visible
What happens during the metaphase of mitosis?
chromosomes line up at the cell equator
Where do the amino acids come from that are used to make proteins on the ribosomes of the rougher?
cytoplasm
What process does the term mitosis refer to?
division of the nucleus
An example for mutations that are caused by unusual chromosome numbers in humans is the
down syndrome
There are three cases where inheritance patterns deviate from the Mendelian rules. These are (a) (b) (c)
incomplete dominance, maternal inheritance, linked genes
What lasts longer the mitosis phase or the resting or interphase of the cell cycle?
interphase
Another important impact of PCR was in the field of forensics. Here .................................................
it revolutionized CSI techniques
What is crossing over and where does it occur?
it's when two chromosomes exchange genetic material. Occurs in proface
Which amino acid has the highest number of 3 -base -letters code for it?
leucine
What makes bacteria so useful and dangerous is the enormous rates of propagation they can reach under favorable conditions. How do we call the phase in which they reach maximal propagation rates?
logarithmic phase
What is the mechanism by which a plant cell divides?
mitosis
Does the division time of cells match the renewal time of the organ they are part of?
no
Is every proteinogenic amino acids exactly matched with one codon in the DNA sequence or not?
no
What are introns?
non-coding DNA
Why are viroids the new great threat to the global human populations?
not a threat they only affect plants
In which organisms was mitosis first observed?
onion cells
Which takes longer the renewal of a cell or that of an organ?
organ
What is a genome?
organism's complete set of DNA
When organisms are wounded, they produce substances that sponsor cell division to heal it. In animals we call this factor........................................
platelet derived growth factor
Some single genes affect more than one trait. We call this ........... A good example for it is the appearance of ...............
pleiotropy, sickle cell
There is a second type of cell division called meiosis. What is the purpose of having a second type?
propagation
Name a bacteria species that becomes lethally pathogenic due to the presence of .........................
prophage virus genes, Scarlet fever
While DNA or nuclein was recognized as the substance relating to inheritance in the 1890s, in the first half of the 20th century people believed that inheritance is associated not with nucleic acids but with ..............
proteins
We know already since 1884 that nucleic acids contain two types of nitrogenous bases: the........ and the..........
purines, pyrimidines
What is the role of the second gap phase G2?
quality control
Name 3 categories of mutagenesis-inducing factors!
radiation, carcinogens (chemicals) bacteria and viruses
What is inverse transcription and in which organisms does it occur?
retroviruses like HIV occurs in humans
What is a gene?
sequence of nucleotides in DNA
Give a bloody example (excuse my French!) for a single-base mutation that changes the shape of the concerned cell type!
sickle cell anemia
Polygenic inheritance is when one trait is influenced by multiple genes. Name such a trait in humans and animals!
skin color
Name a virus epidemic that was the plaque and likely downfall of the ancient Rome.
small pox
The mRNA bonds to the small/large subunit of the ribosomes and the tRNA binds to the small/large subunit of the ribosome (circle right answer!)
small, large
Which organs have the fastest turn-over or renewal times? Name two?
stomach lining, lungs
The use of inverse transcription was crucial in the development of .................. genes and through it the development of something the world had never seen before - ................. Organisms
synthetic, GMO'S
A sophisticated hypothesis of aging was forwarded by Dr. Hayflick, in which he proposed that the stop of cell divisions was linked to a steady process of reducing the number of .....................(chromosomes??) Make one argument that does not support the Hayflick hypothesis of aging!.........................................
telomeres, nerve cells don't divide
What was the most surprising discovery about the nucleus division called mitosis?
the discovery of chromosomes
What is the effect of having multiple sets of chromosomes in berries?
they get bigger
What is the role of tRNA molecules?
to bring the amino acids to the ribosomes
Ribosomes participate in replication/transcription/translation of the Genome?
translation
Which infectious biological particle is called "genes in a box"?
virus
Name a mutation that affects our metabolism and which lies far back in an ancestor of both primate apes and humans?
vitamin c deficiency
When grown in culture, plant cells suddenly reveal the need for substances; we thought they can produce easily. Which substances do I talk about?
vitamins
Recessive genetic disorders are only a real threat...................................... Therefore it is recommended for concerned parents to undergo genetic testing.
when both parents have it
When is a mutation in a single base most severe in its consequence?
when changing amino acid to stop codon
When is a mutation in a single base silent or insignificant?
when it codes for the same amino acid
Which cells were the first tried for DNA extraction?
White blood cells
How do human sex chromosomes determine the human sex?
XX women XY man
Did the original discoverer of DNA know that DNA came from the nucleus of a cell?
Yes, found it in nuclein
Replication reminds us of a certain type of textile closure and do not mean Velcro or buttons but ....................
Zipper
Among the human disorders most are (a) recessive (b) dominant
a
. Mendel had incredible luck. He chose 7 traits for his studies. All of these traits were (a) either dominant or recessive (b) each on a different chromosome © determined by only two alleles Circle right answers!
a, b, c
What happened when Mendel crossed a purple with a white flowering pea? (a) to the F1 generation ................. ((b) to the F2 generation ................. © which color is dominant? ...................
all purple flowers, 3 purple one white, purple
Mutating errors can occur in (a) replication, (b) transcription, (c) translation. Circle right answer!
all three
One theory of the aging process submits the hypothesis that aging is due to errors in (a) replication , (b) transcription , (c) translation ? Circle right answer!
all three
tRNA has to specific sites: one for the .................. and one for..........................
amino acid, binding to the mRNA
Even in rapidly dividing tissues (meristems), the division of a nucleus or even the cell (a) occurs incessantly without break (b) needs some time in between to replicate the DNA and make some protein. Circle right answer!
b
Some inherited traits have more than 2 alleles to a gene. Give one example!
ABO blood type
What is a mutation? How is it defined?
An error in the amino acid sequence, it's a change in the nucleotide sequence
How many proteinogenic amino acids exist in all kingdoms of life?
22
Give the size of the human genome in ............. coding genes and in .............base pairs (BP, i.e. A-G, C-G pairs)!
25,000, 3 billion
How many chromosomes has a human ......And how many do have orangutans, chimps and gorillas ......?
46, 48
Finish the sentences. A sperm cell contains up to .....% DNA. Its like a ...... with a tail.
50, nucleus
How many 3-letter code combinations derive from 4 different nucleotide bases? Is it 4, 16, or 64?
64
How many chromosomes exist in a pea cell?
7
During which cellular events did they first see chromosomes to appear?
Cell division
Which are the 3 most important parts of chromosomes?
Chromatids, centromere , telomere
what does the name "chromosome" mean?
Chromo means color and some means body
Why does the nucleus DNA needs to be transcribed to mRNA?
DNA can not leave the nucleus so it needs a messenger
Why is the S phase necessary to undergo another division?
DNA replication
What is a promoter gene or codon?
DNA triple sequence where the RNA binds to the DNA
Abnormal numbers of chromosomes lead to disorders. Name one.
Down syndrome
What is polyploidy?
Error in chromosome distribution that leads to increased numbers of chromosomes sets.
Name three common mutations in humans that we encounter in daily life!
Freckles, vitamin c deficient, lactose intolerance
Name 3 virus epidemics that occurred in the last 50 years!
HIV, haven flu, west Nile
when did science start to suspect that the nucleus has something to do with inheritance?
In 1833
Why are certain traits only determined by the mother parent and not by the father?
The genes are in the mitochondria only come from the mother
What is a karyotype and what is it used for?
Inventory of your chromosomes used to detect abnormalities
If we differ from Neanderthal homos and chimpanzees and among each other by less than 1 % DNA sequences, what does that mean for defining us as humans?
It might not have to do with DNA sequence
Why was the invention of the PCR technique a milestone in DNA research?
It revolutionized our life like crime and Neanderthals being our ancestors
Why is it bad for an organism if one cell type multiplies and takes over?
It uses up space for the healthy cells
Is the isolation of DNA from cells an old or rather recent event? explain?
Old because it was isolated from pus (white blood cells) in 1869
Which species has the highest number of coding base pairs on planet earth?
Plant
The individual differences in DNA sequences are often non-functional DNA stretches called ........ Or .........
STR, junk DNA
If you extract DNA from animal cells or strawberries what and why do you add to your extraction buffer?
Shampoo to dissolve the cell membrane
The crucial evidence that DNA determines inherited traits came from an experiment by Hershey and Chase using a virus. What did they do to figure it out?
They used a radioactive phosphate label for nucleic acid
Which amino acid has only one code for it?
Tryptophan
How do you become a male bee?
Un fertilized egg
