Answer:
who was the first scientist to discover a cell when observing a tin section of deed cork under a crude compound microscope?
Robert Hooke!
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Answer:
D. heterotrophic by ingestion, pseudopods
Explanation:
Protists are generally classified as all eukaryotic organisms that are not plants, animals or fungi. Example is amoeba, paramecium etc.They may be unicellular or multi cellular in nature.Most exist in colonies.
Their mode of nutrition can be photosynthetic or hetrotrophic. Hetrotrophic protists can be divided into phagotrophs and osmotrops/saprotrophs. The phagotrophs makes use of the cell body to engulf the food materials as in amoeba ,carry out extracellular digestion before swallowing it.
Osmotrops absorbed dissolved food from surrounding liquid environments directly. (Some photosynthetic protists can also be heterotrophic.
Amoeboid movement is the mode of locomotion of protists and some other eukaryotes. It involved the protrusion of cytoplasm, which exert pressure on the cell membrane to form pseudopodia and the posterioly evolved <u>Uropods. </u>
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<u>Sol-gel theory has been proposed to expalin this movements, The ectopalsm of amoeba is gelly-like , while the endiplams is less viscpus and said to be sol. The interchange of the cytoplasmic fluis between the endo-and ecto plasm gives the SOL-GEL propulsion of the protopalms for the amoebic moveemnts .</u>
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<u>The false feet(psuedopodium) drags the amoeba along in the direction of the flow of the cytoplasm.</u>
Therefore option D is the right option
Are a class of lipids whose molecule has a hydrophilic "head" containing a phosphate group, and two hydrophobic "tails" derived from fatty acids, joined by an alcohol residue. ... They can form lipid bilayers because of their amphiphilic characteristic.
Question continuation;
..........type B. Type A is found to be more common in the mainland population from which the island was settled.
How could a geneticist best explain the dominance of blood type B in the island population?
Multiple choices;
A. Random mutations have occurred in the island population.
B. Genetic drift has reduced the frequency of type A individuals.
C. Natural selection has only occurred in the mainland population.
D. Environmental conditions on the island are less favorable for type B individuals.
Answer;
B. Genetic drift has reduced the frequency of type A individuals.
Explanation;
-Genetic drift is a mechanism of evolution in which allele frequencies of a population change over generations due to chance.
-It occurs in all populations of non-infinite size, but its effects are strongest in small populations.
Answer:
ovule, plant structure that develops into a seed when fertilized. ... A small opening (the micropyle) in the integuments permits the pollen tube to enter and discharge its sperm nuclei into the embryo sac, a large oval cell in which fertilization and development occur.
