17. D
18. A
19. D
these are the answers for the questions above
Answer:
In first generation one allele pair with an offspring is lethal, hence the phenotypic ration is 2:1
Explanation:
Let the allele representing the tailless trait with in mice be "t"
the allele representing the wild-type offspring trait with in mice be "t+"
Generation I
Genotype of tailless mice is "tt+"
Cross between two tailless mice will produce following offspring
tt+ * tt+
tt, tt+, tt+, t+t+
Out of four offspring, the one with genotype "tt" is lethal, thus ration of tailless and wild-type offspring is
2:1
Generation I
Genotype of tailless mice is "tt+"
Genotype of wild-type offspring is "t+t+"
Tailless mice crossed with wild-type mice produce-
tt+ * t+t+
tt+, tt+, t+t+, t+t+
Ratio of tailless to wild-type progeny is
2:2
1:1
Outside factors seem to effect the Earth on some aspects and seem not to effect it on others.
For example, water tide is effected by the moon's gravitational force, and seasons effects by Earth's location and orientation in relation to the sun.
Some of the environment seems to result by processes internal to Earth's "closed system". For example, overpopulation occurs when a species' population exceeds the carrying capacity of its ecological niche. In this case, ecology plays as the "closed system" factor. Another example can be Drought, which can result from a number of causes based of the weather and climate of a region. In this case we can say those causes are bound to the "closed systemness" of Earth, and shape the problematic situation of drought.
Hope this is helpful :)
The child experiences difficulty following the educator's headings. The ADHD is a mental issue of the neurodevelopmental sort. It is described by issues focusing, over the top action, or trouble controlling conduct which isn't proper for a man's age.