Fossils, or preserved parts of organisms from the distant past, have shown that species change over time. Radiometric dating can be used to determine the age of fossils by measuring the how much of the radioactive materials in each rock layer have broken down.
The immune response is the body's defense mechanism against the pathogens. The immune response of the body protects it from bacteria, viruses and multiple other disease causing organisms. The normal development of this protective immune response of the body is produced by as a result of the hormones which are produced by the thymus gland. The thymus gland produces the T-lymphocytes, which are important for a healthy immune response. The thymus gland secretes thymosin which is crucial for the development of these cells.
Hence, the answer is 'thymus gland'.
Answer:
a) 99.93%
b) 99.98%
Explanation:
Given that:
Total population size was only around 18 individuals ( for black-footed ferret)
If the annual survival rate in the wild was 0.4%.
a)
What is the probability that all 18 would have died in a single year?
To find that; we multiply the annual survival rate in the wild with the total population; which is:
(0.4%×18) = 0.072%
Then; we subtract it from a total of 100% in order to determine the probability that all 18 would have died in a single year.
= (100.00% - 0.072%)
= 99.93%
b)
What is the probability that all 18 would have died in a single year if canine distemper was present?
Given that;
Because of the presence of canine distemper disease, the annual mortality rate might have been as high as 0.89.
To determine the probability; we have:
1 - Annual mortality rate = annual survival rate
1 - 0.89 = 0.11 %
Therefore, 0.11% of 18 individuals = (0.0011 × 18)
= 0.0198%
Probability that all 18 would have died in a single year if canine distemper was present = 100 - probability of annual survival rate
= (100 - 0.0198)%
= 99.98%
Answer:
b. di uses across a synaptic cleft from a neuron to a muscle cell.
Explanation:
A neurotransmitter is di uses across a synaptic cleft from a neuron to a muscle cell. Neurotransmitters are chemicals which enable neurotransmission. In reaction to an impulse a motor neuron axon secretes a neurotransmitter and causes the muscle fiber to contract. It is a chemical messenger which passes on the signals across the chemical synapse.
DNA Helix, DNA Supercoils, Nucleosome, Chromosome
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