Endocrine gland - a group of cells that secretes substances into the blood or directly into an organ.
Differ from exocrine glands, endocrine glands have no ducts and secrete products (hormones) directly into blood.
Hormone - a substance produced by cells that helps specific groups of cells to perform specific functions. It is a product of endocrine gland which functions as chemical messengers to stimulate other cells.
Duct – a channel or tube that conveys a substance. It is part of the exocrine glands (such as salivary glands) which makes contact with surface .
Answer:
New allele combinations are acted upon by natural selection.
Explanation:
Recombination may be defined as the process of the exchange of the genetic material between the homologous chromosomes of the non sister chromatid. The combined trait will be visible in the upcoming generation.
The recombination allows the generation of the new genes in the population. These new genes if beneficial for the population will be pass to the next generations. The new allele will be favored by the natural selection and increases the chance of survival of the population.
Thus, the correct answer is new allele combinations are acted upon by natural selection.
The species was a keystone species.
Keystone species are the species that ''hold the ecosystem together''.
They have an important role in the trophic networks (food chains) and often they can even afflict changes in the abiotic part of the ecosystem (change the composition of soil, purify the water, lower the effect of the wind etc)
Therefore, when a keystone species is removed it affects greatly the whole ecosystem.
Answer:
7.5
Explanation:
The first note is a half note that is (2 beats). The second note is an 8th note (1/2 a beat). The 3rd note is a whole note (4 beats). The last note is a quarter note so (1 beat).
2+0.5+4+1= 7.5
Answer: overpopulation of predators
Explanation: Overpopulation of predators is the correct option. Predators are the organisms which kill other organism so as to obtain them as food. The organism being killed is called as the prey.
If the population of the predators increase this will lead to the extinction of many species of prey. As it is evident that every organism in the ecosystem has a typical role to play. Therefore, it can be said that role of prey will not be performed and this may lead to disturbance in the ecological balance.
