Answer:
every muscle cell of the motor unit is stimulated to contract.
Explanation:
Stimulus in biology can be defined as an obvious change in either the chemical or physical structure of an organism' environment (either external or internal). Thus, all living organisms (both animals and plants) respond to changes in their environment and consequently, an appropriate response or reaction is made. Also, stimulus arising from within the organism is known as internal stimulus while those from its environment are known as the external stimulus.
In organisms, the specialized cells that detect stimulus are generally known as sensory receptors while a group of these receptors is referred to as sense organ. Therefore, the senses are necessary for behavior because stimuli must be sensed in order to respond.
Stimulus control can be defined as a phenomenon that arises when a living organism responds or behaves in the presence of a stimulus and in another way in the absence of a stimulus.
For example, opening the door of a microwave oven as soon as its timer beeps.
Example II; When your body touches a hot object, you quickly move away and feel some pain subsequently.
Action potentials generates the nerve impulse in a motor neuron.
When an action potential is generated within a motor neuron, every muscle cell of the motor unit is stimulated to contract.
<span>Answers;
1.Breeding of individuals that have genes for two different characteristics; Dihybrid cross
2.A grid system used to predict possible combinations of genes due to random fertilization; Punnet square
3 A condition in which both alleles are dominant; Codominance
4.when more than two alternatives exist for a gene; multiple alleles
5.A condition in which neither pair of alleles is dominant or recessive, so the traits blend in the phenotype ;Incomplete dominance;
Explanation;
</span>Dihybrid cross;
<span>It involves the breeding of individuals that have genes for two different characteristics. It involves the cross of individuals that are both heterozygous for two different traits. For example two different traits in a pea plant; color and shape; for color we have; Y-allele for yellow seeds and y- allele for green seeds, For Shape trait; R-allele for round seeds and r-allele for wrinkled seeds. So the dihydbrid cross would be (RrYy </span>× RrYy).
<span>
Punnet square;
</span><span>This a grid system or a square diagram that is used to predict possible combinations of genes due to random fertilization. It is used by biologists determine the probability of an offspring having a particular genotype.
</span><span>The letters on the outside of a Punnett Square stand for the parent allele.
</span>
Codominance;
<span>This is a condition in heterozygotes in which both members of an allelic pair are dominant and both contribute to the phenotype.
A good example of codominance is the ABO blood group; A person with blood group AB, it means that both the A allele and B allele are equally expressed.
Multiple alleles
</span><span>This is when more than two alternatives for a gene exist.
Examples of multiple allelism in human;The genes of the ABO blood group system. The human ABO system is controled by three alleles, namely; A-allele, B-allele and O-allele.
Incomplete dominance;
</span><span>This is condition in heterozygotes in which both members of an allelic pair are neither dominant nor recessive to other alleles, so the two traits blend in the phenotype of the individual.
An example; is a snapdragon flower that is pink as a result of cross-pollination between a red flower and a white flower. Which means neither the white allele or the red allele are dominant. </span>
The structure of the skin is an effective barrier against bacteria. The multiple layers of epidermis, while can be invaded by foreign organisms, has a high turnover rate which means it is constantly shedding, therefore even the bacteria is shed protecting the body. Lastly, the skin's lipids maintain an acidic pH which slows and stops growth and replication of bacteria.
Answer:
no
Explanation:
a furrow is a trench dug by a plow or (insert word for the name of a garden tool that looks like a naughty word) for planting seeds or to carry water for irrigation.
B, is the answer. I believe.
