Answer:
The color of the light changed
Explanation:
Correct on edge
Answer:
This question lacks options, the options are:
A. All 270 tall plants were heterozygous
B. All 270 tall plants were homzygous.
C. Only 90 plants were homzygous.
D. All dwarf plants were homzygous.
The answer is D.
Explanation:
This question involves a single gene coding for height in pea plants. The allele for tallness (T) is dominant over that of dwarfness (t). This means that a dwarf plant can only be homzygous recessive (tt) while a tall plant can either be homzygous (TT) or heterozygous (Tt).
According to the question, two tall heterozygous pea plants were crossed i.e. Tt × Tt. Based on this cross, a phenotypic ratio of 3:1 is expected, which is in accordance with the 270 tall plants and 90 dwarf plants (360 total) that was obtained in the cross. Since dwarfism in pea plants is a recessive trait, this means that all the dwarf plants produced in this cross (90) were homzygous (tt).
<u>Answer:</u>
Fossils are the sources to learn the changes on the earth and how much it changed in these years. Its provides us with information about the existence of plant and animals in the past.
Actually, the fossils we found till the date are the ancestors of the plants and animals that live today. Moreover, some fossils of animals are easily identifiable since they exist till the date.
But there are fossils of animals that exist no longer in the earth. By studying and analyzing the fossils, one can tell how life on the earth has changed.
Also, we can learn about the ancestors of the plants and animals and how their long life existed on earth.
In other words, one can learn where and how those organisms were lived. So that we can know about our ancient environments.
Answer:
recognizes a hormone’s chemical structure
Explanation:
In living systems, chemical messengers called hormones are secreted into the body via the bloodstream or ducts by certain glands called endocrine glands e.g pancreas, hypothalamus etc. These hormones are meant to effect a physiological change in certain cells called TARGET CELLS.
In biology, a target cell is any receiving cell that has the ability to respond to signals and messengers like hormones. This responding ability of hormones is due to the possession of specific receptor sites for the specific hormones. The receptor on a particular target cell recognizes that specific hormone's chemical structure, hence, will only respond to it.
For example, an insulin hormone secreted by the pancreas will only be responded to by a target cell that recognizes the chemical structure of the insulin protein using its receptor molecule.
