Fern spore germinates into prothallus.
Explanation:
Ferns are members of phylum pteridophyta, the vascular cryptogams.
These are first land plants which are known to have a distinct conducting system of xylem and phloem.
They reproduce by forming spores that germinates into a heart shaped gametophyte.
The gametophyte of the fern is called prothallus.
The heart shaped gametophyte has root like structure called rhizoids.
These rhizoids anchor the gametophyte to the substratum.
Answer: The correct answer is-
C. Insulin secretion in response to high blood sugar.
D. Increased heart rate in response to exercise.
F. Proton pumping to maintain a proper pH level.
Homeostasis can be described as a tendency of living organisms to maintain a state of stable internal environment. In other words, it is the tendency to resist any change in the optimal conditions for survival.
It is brought by several regulatory mechanisms in the body such as regulation of body temperature, regulation of pH, regulation of osmolarity etc.
- Whenever there is high blood sugar level, insulin hormone is secreted from pancreas that reduces the blood sugar level.
- Heart rate is increased in response to exercise so that more oxygen is transported through blood circulation and more amount of energy is harvested through cellular respiration in the form of ATP ( required in exercise).
- Pumping of proton maintains a proper pH level ( such as in lysosomes, where pH is highly acidic, high proton concentration is regulated through proton pumping).
Thus, option C), D), and F) are the examples of feedback mechanisms that help in maintaining homeostasis.
Answer:
One of the parents is heterozygous for red (Rr) and the other is homozygous for white (rr)
Explanation:
The ratio of red flowers to white flowers is roughly 50:50 in this cross (51:47)
Assuming red is the dominant trait, and white is the recessive trait, the parents would be Rr (heterozygous red) x rr (homozygous white).
The resulting punnet square (attached) shows that the genotypes are 50% Rr and 50% rr, which would be 50% red and 50% white. Therefore the parents are RR and Rr.
If red is the recessive phenotype, then the opposite would be true, the white parent would be heterozygous and the red parent would be homozygous.
Answer:
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Explanation:
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Answer:
Explanation:
Birds with longer, thinner bills, such as hummingbirds, bananaquits, and sunbirds, insert their bills into the flower so they can lick at the nectar directly. ... Nectar-eating birds are called nectivorous if nectar does make up a large proportion of the majority of their diet, such as with hummingbirds.