Answer:
Within double-stranded DNA, the nitrogenous bases on one strand pair with complementary bases along the other strand; in particular, A always pairs with T, and C always pairs with G. Then, during DNA replication, the two strands in the double helix separate.
Explanation:
The four nitrogenous bases of DNA are thymine, adenine, guanine, and cytosine. Guanine and cytosine are bound together by three hydrogen bonds; whereas, adenine and thymine are bound together by two hydrogen bonds. This is known as complementary base pairing.
Answer:
recombination frequency = 4.5% or 4.5mu
Explanation:
to calculate the frequency of recombination between these genes
we have,
recombination frequency = [ number of recombinnants/total number of offsprings) x 100
total offspring = 88 + 103 + 6 + 3
total offspring = 200
Gl ra 88............................ parent
gl Ra 103.........................parent
Gl Ra 6..................................... recombinant
gl ra 3................................................ recombinant
recombination frequency = {6+3/88 + 103 + 6 + 3} x 100
recombination frequency = 9/200 x1oo
recombination frequency = 0.045 x 100
recombination frequency = 4.5% or 4.5mu
Agents that paralyze skeletal muscle by simple competitive inhibition of acetylcholine at muscle receptor sites are called?
a. nondepolarizing
b. depolarizing
c. antagonizing
d. repolarizing
Answer:
a. nondepolarizing
Explanation:
As the nerve impulse arrives, the synaptic end bulbs of the motor neurons release acetylcholine in the synapse. Acetylcholine binds to its receptors present at the motor endplate. This results in the opening of an ion channel in the ACh receptor to allow the movement of the Na+ into the cell. This makes the inside of the muscle fiber more positively charged, that is, depolarized.
Depolarization triggers a muscle action potential. Drugs or chemicals that paralyze skeletal muscle by competitive inhibition of acetylcholine at muscle receptor sites are called non-depolarizing as they do not allow the acetylcholine to facilitate the depolarization of the muscle fiber.
The sun--solar energy--is at the heart of the cycle of life, with all the sustenance relationships referred to as the food web. The sun is the ultimate source of energy for animals, but its energy must be harnessed by plants before it can be used by animals. Animals get energy by processing complex foods.
<u>Answer</u>:
A) Determine the average number of times during a week in May that a group of bees visits flowers.
<u>Explanation</u>:
These observations may be mostly qualitative in nature at the real or exploratory stage of a study, but trials are usually done to show them in the form of quantitative data at some later stage. It is important that experimental information must be accumulated and arranged in a sequential fashion and in a form which can be understood by all: ideas may be more easily extracted, and results will be more easily drawn from data which have been arranged into a coherent pattern.
