Answer:
1- DNA: a specific DNA sequence encodes a transcription factor which activates the expression of target genes involved in cell differentiation
2- RNA: short non-coding RNAs may bind to enhancer regions and thus activate the expression of target genes involved in cell differentiation
3- Environmental factor: temperature may control the expression of genes involved in cell differentiation pathways
Explanation:
The deoxyribonucleic acid (DNA) contains the genetic material required to encode proteins. Some of these proteins are transcription factors involved in the activation of diverse signaling pathways, including, for example, cell differentiation and proliferation. On the other hand, microRNAs (miRNAs) are short non-coding RNAs that have the ability not only to repress but also to activate transcription by binding enhancer sequences. The miRNA activation mechanism has recently been discovered. In consequence, some miRNAs may potentially activate the expression of target genes involved in cell differentiation (e.g., <em>c-myc </em>gene). Finally, environmental factors (e.g., nutrient availability, salinity, temperature, etc.) may also activate gene expression and thus control diverse pathways such as cell differentiation, cell proliferation and cell death (apoptosis).
Answer:
D
Explanation:
Osmosis is a biological phenomenon whereby the molecules of a solvent moves through a selective permeable membrane from an area of low solute concentration to an area of high solute concentration.
There are three types of osmotic solutions viz;
Isotonic; which has an equal solute concentration
Hypotonic; which has a lower solute concentration
Hypertonic; which has a higher solute concentration
When a living cell is placed in a solution, the solvent molecule (which is usually water) moves in or out of the cell depending on whether the cell has a higher solute concentration (hypertonic) or lower solute concentration (hypotonic) in comparison with the solution it was immersed in.
A good example can be observed in the absorption of water by the root hairs of plants; root hairs, due to the accumulation of minerals, possess a lesser concentration of water molecules than the soil i.e the root hairs are hypertonic. Due to this osmotic gradient, water (solvent) moves from the SOIL, which has a lower concentration of solute, to the ROOT, which has a higher concentration of solute.
Answer:
Frequency of allele "A" 
Frequency of allele "a" 
Explanation:
Given,
The alleles for flower color are A (yellow) and a (green) where A is dominant to a.
The genotype frequencies are -
AA - 
%
Aa - 
%
aa- 
%
so the frequency of allele A is equal to 
As per Hardy Weinberg's equation 1-
Substituting the value of "p" in above equation, we get -
So the Frequency of allele "A"
Frequency of allele "a"
Answer:
Question:- where is the whale meat being sold in Japanese markets coming from?
Observation:- The availability of whale meat in Japanese markets exceds that expected from the reported legal captures of whales.
Hypothesis:- If whales are being illegally harvested, reported whale captures will be far lower than the number of captures predicted by genetic analyses of whale meat in markets.
Prediction:- Whales are being harvested illegally and their meat sold in markets in Japan.
Test:- Scientists subject whale meat to genetic analysis to determine its likely capture location and to estimate whale captures at that location.
Explanation:
Scientific method is a core problem solving approach in biology, chemistry and physics.
The scientific method has five basic steps:
1) Observation: Data you collect during an experiment
2) Question: the thing that you want to know. The question you want an answer to.
3) Hypothesis: this is a possible explanation that can be tested to see if it is likely correct or if we need to make a new hypothesis.
4) Prediction (based on the Hypothesis): this is an outcome we'd expect to see
5) Test: to perform an experiment on the data available.
The answer is amino acid. Amino acids are the basic structures of protein
