× Didn't find what you were looking for? Ask a question
Top Posters
Since Sunday
5
a
5
k
5
c
5
B
5
l
5
C
4
s
4
a
4
t
4
i
4
r
4
Home Q & A Board Biology-Related Homework Help General Biology
Ask your year-one biology questions here.
New Topic  
Subject
Last post
Why does understanding the origin of life require the collaboration of biologists, chemists, ...
Why does understanding the origin of life require the collaboration of biologists, chemists, ...
Why does understanding the origin of life require the collaboration of biologists, chemists, geologists, and atmospheric scientists?
 
  What will be an ideal response?
fpotestio   33   1 Reply
6 years ago
Why can't we use modern atmospheric conditions to infer the origin of life? What will be an ...
Why can't we use modern atmospheric conditions to infer the origin of life? What will be an ...
Why can't we use modern atmospheric conditions to infer the origin of life?
 
  What will be an ideal response?
DustiG   19   1 Reply
Mandamomm11
6 years ago
Identify all of the potential energy sources for prebiotic chemical reactions in this picture. ...
Identify all of the potential energy sources for prebiotic chemical reactions in this picture. ...
Identify all of the potential energy sources for prebiotic chemical reactions in this picture.
 
  What will be an ideal response?
peeeps   37   1 Reply
6 years ago
If a modern novel life-form were made, what would this tell us about LUCA?
If a modern novel life-form were made, what would this tell us about LUCA?
If a modern novel life-form were made, what would this tell us about LUCA?
 
  What will be an ideal response?
krautkin   44   1 Reply
6 years ago
Why might the analysis of endosymbiotic bacterial genomes be misleading for understanding the ...
Why might the analysis of endosymbiotic bacterial genomes be misleading for understanding the ...
Why might the analysis of endosymbiotic bacterial genomes be misleading for understanding the minimal gene set?
 
  a. They may have lost genes that would have been essential to early life-forms because they may have reduced metabolic requ
wyatt7799   22   1 Reply
6 years ago
How does comparative data on genes of extant species help us to make estimates of what happened ...
How does comparative data on genes of extant species help us to make estimates of what happened ...
How does comparative data on genes of extant species help us to make estimates of what happened before the phylogenetic event horizon?
 
  a. Common genes must have existed for a long time.
  b. If the first life-forms consisted of RN
rizzy9   56   1 Reply
Mandamomm11
6 years ago
Why might life be much older than LUCA?
Why might life be much older than LUCA?
Why might life be much older than LUCA?
 
  What will be an ideal response?
mssddeed   29   1 Reply
6 years ago
What does the abbreviation LUCA stand for and what does it mean?
What does the abbreviation LUCA stand for and what does it mean?
What does the abbreviation LUCA stand for and what does it mean?
 
  What will be an ideal response?
Bromandude12   30   1 Reply
6 years ago
The minimum gene set has on the order of:
The minimum gene set has on the order of:
The minimum gene set has on the order of:
 
  a. 2 genes. c. 200 genes.
  b. 20 genes. d. 2,000 genes.
drfhrx   74   1 Reply
6 years ago
What is most critical for understanding the minimal gene set and the origin of life?
What is most critical for understanding the minimal gene set and the origin of life?
What is most critical for understanding the minimal gene set and the origin of life?
 
  a. the number of genes
  b. the functions of the genes
  c. the stable environments of bacteria with the most reduced genomes
  d. the
JuliusImus   28   1 Reply
6 years ago
Which of the following is not a function of an essential gene?
Which of the following is not a function of an essential gene?
Which of the following is not a function of an essential gene?
 
  a. energy metabolism
  b. fatty acid/lipid metabolism
  c. nucleotide synthesis
  d. RNA coding
  e. nuclear transport
nika   36   1 Reply
6 years ago
How has the role of horizontal gene transfer (HGT) in evolution changed over time?
How has the role of horizontal gene transfer (HGT) in evolution changed over time?
How has the role of horizontal gene transfer (HGT) in evolution changed over time?
 
  a. Early life-forms were fixed entities and the only way to adapt was through HGT. HGT no longer occurs.
  b. Early life-forms had modular genomes
cokierae1   47   1 Reply
6 years ago
Why is there natural selection for reduced parasitic bacterial genomes?
Why is there natural selection for reduced parasitic bacterial genomes?
Why is there natural selection for reduced parasitic bacterial genomes?
 
  a. The parasitic lifestyle eliminates metabolism leading to gene loss.
  b. Parasites have reduced metabolic needs leading to gene loss.
  c. Parasitic b
hongocbaotram   87   1 Reply
6 years ago
This figure shows horizontal gene transfer and the early evolution of life. By this diagram, which ...
This figure shows horizontal gene transfer and the early evolution of life. By this diagram, which ...
This figure shows horizontal gene transfer and the early evolution of life. By this diagram, which of the fol-lowing is NOT true?
 
  a. Bacteria have transferred genes to eukaryotes twice.
  b. Bacteria have transferred genes to arch
mndcurrier   32   1 Reply
6 years ago
Why is fission likely to be a method of reproduction in early cells?
Why is fission likely to be a method of reproduction in early cells?
Why is fission likely to be a method of reproduction in early cells?
 
  a. The easiest way to divide genetic material is to split it in two.
  b. Hypercycles that become unstable split apart.
  c. Modular genomes transfer well b
Slorquet   25   1 Reply
6 years ago
In early cell evolution, why would natural selection favor division into equal-sized daughter cells? ...
In early cell evolution, why would natural selection favor division into equal-sized daughter cells? ...
In early cell evolution, why would natural selection favor division into equal-sized daughter cells?
 
  a. Splitting into two equal parts is the most energetically efficient method.
  b. Two daughter cells is the most efficient way t
hamzawild6   38   1 Reply
6 years ago
Encapsulation of a hypercycle would not be favored when:
Encapsulation of a hypercycle would not be favored when:
Encapsulation of a hypercycle would not be favored when:
 
  a. the costs of a membrane exceed the benefits of the cycle.
  b. the membrane provides a defensive mechanism.
  c. natural selection favor mutations in component membe
azuniga34   52   1 Reply
6 years ago
Molecular mutualism is: (Multiple Choice)
Molecular mutualism is: (Multiple Choice)
Molecular mutualism is:
 
  a. an interaction of molecules that disrupts hypercycles.
  b. an interaction of two species to the benefit of both.
  c. replication of RNA by another enzyme.
  d. an interaction of molecules tha
cokierae1   30   1 Reply
6 years ago
Which evolved first? (Multiple Choice)
Which evolved first? (Multiple Choice)
Which evolved first?
 
  a. prokaryotes c. eukaryotes
  b. organelles d. mitochondria
Slorquet   37   1 Reply
6 years ago
Which of the following is not a hypothesis for the origin of viruses?
Which of the following is not a hypothesis for the origin of viruses?
Which of the following is not a hypothesis for the origin of viruses?
 
  a. Viruses are escaped selfish genetic elements.
  b. Viruses are the remnants of parasitic cellular organisms selected for a reduction in size.
  c. Virus
Asian101   26   1 Reply
6 years ago
What is a common feature of all organisms?
What is a common feature of all organisms?
What is a common feature of all organisms?
 
  a. DNA in circular chromosomes c. nucleus
  b. organelles d. cell structure
hamzawild6   32   1 Reply
6 years ago
This figure demonstrates a DNA repair mechanism. What property of DNA makes such repair possible in ...
This figure demonstrates a DNA repair mechanism. What property of DNA makes such repair possible in ...
This figure demonstrates a DNA repair mechanism. What property of DNA makes such repair possible in DNA but not RNA?
 
  a. DNA uses deoxyribose instead of ribose.
  b. DNA uses thymine instead of uracil.
  c. DNA is a double hel
Mai Dinh   51   1 Reply
6 years ago
Why is DNA favored over RNA as genetic material?
Why is DNA favored over RNA as genetic material?
Why is DNA favored over RNA as genetic material?
 
  a. DNA is more stable and thus is a more efficient transmission system.
  b. DNA can self-replicate.
  c. DNA makes chromosomes.
  d. DNA mutates more readily with a weake
simply--steve   25   1 Reply
6 years ago
Ribozymes are: (Multiple Choice)
Ribozymes are: (Multiple Choice)
Ribozymes are:
 
  a. capable of replicating RNA. c. capable of copying RNA into DNA.
  b. proteins. d. RNA enzymes.
mysttrr   59   1 Reply
6 years ago
Spiegelman and colleagues demonstrated natural selection in RNA replications because in their ...
Spiegelman and colleagues demonstrated natural selection in RNA replications because in their ...
Spiegelman and colleagues demonstrated natural selection in RNA replications because in their experiments:
 
  a. RNA molecules had differential survival and replication rates.
  b. RNA was self-replicating.
  c. the researchers
AreebJ   27   1 Reply
6 years ago
Ok at the schematic diagram of a simple self-replicating system. Such a system demonstrates that: ...
Ok at the schematic diagram of a simple self-replicating system. Such a system demonstrates that: ...
ok at the schematic diagram of a simple self-replicating system. Such a system demonstrates that:
 
  a. natural selection is occurring.
  b. replication is occurring given specific substrates.
  c. replication can occur independ
mssddeed   31   1 Reply
6 years ago
What was LUCA? (Multiple Choice)
What was LUCA? (Multiple Choice)
What was LUCA?
 
  a. the first life-form
  b. the only life-form present before our current lineage
  c. the last universal ancestral life-form, a single individual
  d. a population of life-forms that was the last common a
rutu0309   36   1 Reply
6 years ago
Why was it necessary to do serial transfers in this experiment?
Why was it necessary to do serial transfers in this experiment?
Why was it necessary to do serial transfers in this experiment?
 
  a. Each serial transfer is equivalent to a generation and thus provided an opportunity for natural selection to occur over time.
  b. Each serial transfer was necessa
Bromandude12   29   1 Reply
6 years ago
Why were the first RNA replication experiments insufficient support for the RNA world hypothesis? ...
Why were the first RNA replication experiments insufficient support for the RNA world hypothesis? ...
Why were the first RNA replication experiments insufficient support for the RNA world hypothesis?
 
  a. The experiments did not demonstrate natural selection.
  b. RNA could not adapt to environmental challenges.
  c. The RNA pr
mssddeed   40   1 Reply
6 years ago
What was not an energy source when life first evolved?
What was not an energy source when life first evolved?
What was not an energy source when life first evolved?
 
  a. cosmic rays
  b. volcanic eruptions above ground
  c. volcanic eruptions in deep-sea vents
  d. meteorites
hamzawild6   26   1 Reply
6 years ago
The average ocean temperature is shown in this graph with two different estimates using different ...
The average ocean temperature is shown in this graph with two different estimates using different ...
The average ocean temperature is shown in this graph with two different estimates using different methods. What has been the trend over time?
 
  a. Ocean temperature has stayed the same since Earth formed.
  b. Ocean temperature has
MARISHKA   15   1 Reply
6 years ago
Which of the following certainly was not a source of molecules in the prebiotic soup?
Which of the following certainly was not a source of molecules in the prebiotic soup?
Which of the following certainly was not a source of molecules in the prebiotic soup?
 
  a. meteorites c. prebiotic soup reactions
  b. comets d. DNA
GrayHimakar   22   1 Reply
6 years ago
Which of the following is not a shared property of living things?
Which of the following is not a shared property of living things?
Which of the following is not a shared property of living things?
 
  a. homeostasis
  b. structural organization
  c. sexual reproduction
  d. growth
  e. response to the environment
MARISHKA   28   1 Reply
6 years ago
Where on this tree is LUCA found?
Where on this tree is LUCA found?
Where on this tree is LUCA found?
 
  a. A
  b. B
  c. C
  d. D
  e. E
krautkin   19   1 Reply
6 years ago
When life first evolved: (Multiple Choice)
When life first evolved: (Multiple Choice)
When life first evolved:
 
  a. the oceans were hotter and there was more oxygen than today.
  b. the oceans were hotter and there was less oxygen than today.
  c. the oceans were cooler and there was more oxygen than today.
cbouyer10@gmail   24   1 Reply
6 years ago
Describe a haplotype block.
Describe a haplotype block.
Describe a haplotype block.
 
  What will be an ideal response?
PurpleAngel   33   1 Reply
6 years ago
When comparing recombination rates between a dog with a genome size of 2410 Mb and a mustard weed ...
When comparing recombination rates between a dog with a genome size of 2410 Mb and a mustard weed ...
When comparing recombination rates between a dog with a genome size of 2410 Mb and a mustard weed with a genome size of 100 Mb, which would you expect to have a larger recombination rate per kilobase? Explain your answer.
 
  What will be
niikiii   25   1 Reply
6 years ago
A phylogenetic event horizon is:
A phylogenetic event horizon is:
A phylogenetic event horizon is:
 
  a. a point in the future in which species will diversify.
  b. a phylogeny based on extinct species.
  c. the point at which life started.
  d. a point in the history of life beyond which
rizzy9   25   1 Reply
6 years ago
In the following figure, a double crossing-over event occurs between the Alu elements. How does this ...
In the following figure, a double crossing-over event occurs between the Alu elements. How does this ...
In the following figure, a double crossing-over event occurs between the Alu elements. How does this event describe a means by which introns generate genetic diversity?
 
  What will be an ideal response?
DustiG   20   1 Reply
6 years ago
How can haplotype blocks provide evidence of selective events for a particular allele? What will ...
How can haplotype blocks provide evidence of selective events for a particular allele? What will ...
How can haplotype blocks provide evidence of selective events for a particular allele?
 
  What will be an ideal response?
Kingchris9   29   1 Reply
6 years ago
New Topic  
Home Q & A Board Biology-Related Homework Help General Biology
Explore
Post your homework questions and get free online help from our incredible volunteers
  1261 People Browsing
Start New Topic Take the Tour CoursesNew Study Tools Topics Trending Browse by Textbook
Live Chat
Gallery
  
 622
  
 690
  
 456
Your Opinion
Who's your favorite biologist?
Votes: 586
Previous poll results: Where do you get your textbooks?