Answer:
Flowers produce seeds. Many flowers contain both male and female organs needed to produce new flowers. Flower petals are often colorful or have a scent to attract insects and other animals. The male organ of a flower that has an anther on a stalk (filament).
In a resting state, sodium (Na ) is at a higher concentration outside the cell, and potassium (K ) is more concentrated inside the cell. During an action potential, the sodium levels <u>increase </u>inside the cell.
During an action potential, the potassium level inside the cell decreases, and the sodium level inside the cell increases. That is to say, there is an outflow of potassium and an inflow of sodium ions.
Action potential usually occurs when an electrical signal disrupts the balance of Na+ and K+ within a cell membrane, briefly depolarizing the concentrations of each.
Learn more about potassium here: brainly.com/question/21439467
#SPJ4
He wouldn’t have an increase in melatonin because it promotes sleep activity
That they are both theories of evolutionary change, but the tempo of the change is different enough that we have the two theories. Rapid evolutionary change punctuated with long periods of stasis describes the former while gradual and incremental change over long periods is the description of the later. Natural selection seems to be more important in gradualism than punctuation, but this is <span>a murky area that is argued about often.</span>
Answer:
AaBb × aabb
Explanation:
A test cross is a cross between an unknown genotype (dominant phenotype) with a homozygous recessive genotype in order to discover the actual genotype of the species exhibiting dominant phenotype.
This is because one allele of a gene is capable of masking the expression of another, the allele masking is called DOMINANT allele while the allele being masked is called RECESSIVE allele. The combination of these two alleles is termed heterozygosity.
An organism that is phenotypically dominant for a specific trait may either be heterozygous or homozygous for that gene. For example, a plant gene for tallness with an dominant allele T, and recessive allele t. This plant will need tall if the genotype is TT (homozygous dominant) or Tt (heterozygous dominant). In order to know which of these genotypes the plant actually has, a test cross is conducted.
In this example, two genes A and B are involved. For the first gene, A represents dominant allele while a represents recessive allele. For the second gene, B represents dominant allele while b represents recessive allele.
In a cross involving parents AABB (homozygous dominant for both genes) and aabb (homozygous recessive for both genes), the F1 progeny will all exhibit phenotypic dominance (AaBb).
However, we cannot know the genotype by merely looking at the phenotype. We cannot ascertain yet whether the dominance is heterozygous or homozygous, hence the need for a test cross.
The test cross is between the dominant F1 progeny and a homozygous recessive i.e. AaBb × aabb. Some of the F2 generation will show recessive traits if the unknown genotype is heterozygous.
