Answer:
Directional selection
Explanation:
Here, blue poppies which belonged to China were grown in drier climate of California. Plants who live in drier areas generally have thicker leaves to preserve water. Hence the blue poppies leaves also started to become thick and after several generations thick leaved plants had increased by 42%.
This phenomena would come under directional selection. In directional selection, one of the extreme phenotypes is preferred to adapt better to the environment. Here neither thin leaves were selected nor average leaves were selected, rather the selection preferred thick leaves which lies on other end of spectrum. Hence, this is an example of directional selection.
Answer:
The correct answer is - amoeba: pseudopod; euglena: flagellum; paramecium: cilia
Explanation:
Protists use different type of structures for their movement known as pseudopods, flagella, and cillia.
Pseudopods are the structures found in amoeba in which flowing of protoplasm moves the amoeba forward.
A euglena moves by strikes or whip its flagellum, that is a long appendages, like propeller of a helicopter.
Cilia are thin, very small tail-like structure that stretched outward from the of body of paramecium.
Thus, the correct answer is - amoeba: pseudopod; euglena: flagellum; paramecium: cilia
Answer:
The phenotypic ratio will be 3:1
Explanation:
As per this question there are two phenotypes for seed color, yellow and green. Both the parents are true breeding that means they are homozygous for this trait. Also, all the F1 plants have yellow seed color which clearly indicates that yellow seed color is a dominant trait while green is recessive trait.
The cross of true breeding plants as mentioned above is depicted as under:
Parents YY x yy
/ \ / \
F1 generation Yy Yy Yy Yy
So, as per the law of dominance because of the presence of Y allele, all these progeny will be yellow in color.
Next, when these F1 plants will be crossed, the result will be as under:
F1 generation Yy x Yy
/ \ / \
F2 generation YY Yy Yy yy
The genotypic ratio of F2 generation is 1:2:1
The phenotypic ratio of F2 generation is 3:1
It simply means that in F2 generation, 3 progeny which have allelic combination YY & Yy will be yellow colored while 1 progeny which has allelic combination yy will have green color.
