Answer:
Mitosis
Explanation:
Mitosis is not a source of genetic mutation because it take place mostly in the somatic cells. This is because it does not lead to the production of gametes . In mitosis, the parent cells divide into two daughter cells and each daughter cells are genetically identical to the parent cell because they carry the same number of chromosomes as the parent cell. There is no genetic variation in this.
Answer:
To move substances against a concentration or electrochemical gradient, a cell must use energy. Active transport mechanisms do just this, expending energy (often in the form of ATP) to maintain the right concentrations of ions and molecules in living cells.
Explanation:
Neither the peptide hormones or the metabotropic neurotransmitters such as the catecholamines, can enter their target cells. They bind to surface receptors, which then activate second-messenger systems in the cell. Peptides hormones are the hormones that consist of amino acids; they can be among the intracellular signalling peptides and proteins, and can include insect hormones, gastrointestinal hormones and thyroid hormones, but their actions are not limited to individual cells and they can act systemically.
Answer:
C. 40
Explanation:
Pure-breeding means that the individuals are homozygous for the genes being analyzed.
From Mendel's Law of Dominance we know that the traits that appear in the F1 are the dominant ones.
I will call:
P_ = purple flowers
pp = red flowers
L_ = long pollen
ll = round pollen
Initial cross:
P Pl/Pl x pL/pL
F1 Pl/pL
<u>Test cross</u> (cross with a homozygous recessive individual):
Pl/pL x pl/pl
<u>Expected progeny:</u>
Pl/pl = Parental (purple flowers, round pollen)
pL/pl = Parental (red flowers, long pollen)
PL/pl = Recombinant (purple flowers, long pollen)
pl/pl = Recombinant (red flowers, round pollen)
20% of the offspring have purple flowers and long pollen (PL/pl).
Every time crossing over happens in the meiosis of the F1 individual, both a <em>PL</em> gamete and a <em>pl</em> gamete form. That means that 20% of the offspring will also be pl/pl, and the total proportion of the offspring that will be recombinants will be 40%.
A distance of 1 map unit corresponds to a recombinant frequency of 1%.
A recombinant frequency of 40% therefore means that 40 map units separate the glower color and pollen shape genes.
Producers harness the energy of sunlight and convert it into sugars through the process of photosynthesis.
