Founder effect or population bottleneck refer to events which bring about reduction in the genetic variability of a particular specie population. Such events typically drastically reduce the gene pool of the population and produce a smaller number of population with less genetic diversity. An example of a population bottleneck is a genocide event. Such event will destroy a large percentage of the affected population leaving only a smaller population with less genetic diversity. i hope these helps.
Answer:
Due to lack of nutrients in the soil.
Explanation:
Within a few years the forest was dying because there is no nutrient is present in the soil which can trigger the growth and development of the sol. The fallen parts of trees such as branches, tree and leaves etc are decomposed by decomposers such as bacteria and fungi which turn the fallen materials into nitrogenous materials which can be used by the plant for its growth and development.
Answer:
The correct answers are given below
Explanation:
NK cells- Immunological surveillance
Plasma cells- Antibodies
CD4 lymphocytes- Helper cells
Macrophages- Phagocytosis
CD8 lymphocytes- Cytotoxic
IGg- Antibodies
IgE- Allergies
IgM- Primary response
Answer:
diffusion
Explanation:
Water, carbon dioxide, and oxygen are among the few simple molecules that can cross the cell membrane by diffusion (or a type of diffusion known as osmosis ). Diffusion is one principle method of movement of substances within cells, as well as the method for essential small molecules to cross the cell membrane.
Really, there are multiple questions all rolled into one.I will try to answer them patiently and systematically.
First summarize data.
A. Neither Olivia nor Marcus have freckles (recessive, ff)
B. Both are heterozygous for the hairline trait (dominant Ww)
C. Neither Marcus nor Olivia can roll their tongues (rr).
D. All four children have dimples (dominant Dx)
E. Both Olivia and Marcus are EE (unattached earlobe trait).
F. Marcus can not detect the bitter taste (pp for PTC gene)Olivia has been found to be able to detect the bitter taste, but she is heterozygous for the trait. (Pp for PTC gene)
A. Freckles, F (Dominant)
"Neither Olivia nor Marcus have freckles" =>
both have genotype ff.
None of the children have freckles (i.e. P(F)=0% for freckles in all children)
B. Widow's Peak, W (dominant)
"Both are heterozygous for the hairline trait"
So both have genotype Ww.
Punnett square
W w
W WW Ww
w Ww ww
Since W is a dominant trait, only ww (25%) will have straight hairline, 75% will inherit the widow's peak.
50% of the children will be homozygous (Ww).
C. Rolling tongues, R (dominant)
"Neither Marcus nor Olivia can roll their tongues"
means that both are homozygous recessive, with genotype rr.As in freckles, all children will have genotype rr, so none of them will roll their tongues.
None will be heterozygous. The whole family's genotype is rr.
D. Dimples, D (dominant)
"D. All four children have dimples"
implies that all children have genotype DD or Dd.
It is likely that at least one parent has genotype DD in order to have 100% of children have DD or Dd.Here are some possibilities
Case 1: DD + DD (both homoozygous dominant)
D D
D DD DD
D DD DD
Phenotype: 100% have dimples
Case 2: DD + Dd (one homoozygous dominant, and other heterozygous)
D d
D DD Dd
D DD Dd
Phenotype: 100% have dimples
Case 3: DD + dd (one homoozygous dominant, and other homozygous recessive)
D D
D DD DD
d Dd Dd
Phenotype: 100% have dimples
Case 4: Dd + Dd (both heterozygous)
D d
D DD Dd
d Dd dd
Phenotype: 75% have dimples, 25 do not.Note: all 4 children could have dimples, with probability 31.6%
Case 5: Dd + dd (Heterozygous + homozygous recessive)
D d
d Dd dd
d Dd dd
Phenotype: 50% have dimples, 50 do not.Note: All four children could have dimples, with probability 6.25%.
Case 6: dd + dd (Both homozygous recessive)
D d
d dd dd
d dd dd
Phenotype: all children have no dimples.
Conclusion:Likely genotypes of parents: DD+DD, DD+Dd, DD+dd
Possible genotypes of parents: Dd+Dd, Dd+dd
Impossible genotype of parents: dd+dd
Therefore we know with certainty that at least one of the parents has dimples.
E. Unattached Earlobe trait, E (dominant)
"Both Olivia and Marcus are EE"
(i.e. unattached earlobe trait).
This means that the whole family will have genotype EE, i.e. all are homozygous dominant, and have unattached earlobes.
F. Bitter taste, P (incomplete dominance)
"Marcus can not detect the bitter taste (pp for PTC gene)
Olivia has been found to be able to detect the bitter taste, but she is heterozygous for the trait. (Pp)"
P p
p Pp pp
p Pp pp
Probability for each single child being able to taste the ptc paper is 1/2.
Probability for all children being able to taste the ptc paper is (1/2)^4=1/16.
If Violet cannot taste the ptc paper, her genotype is pp.
We do not know for sure how many of the children can taste the ptc paper.
The most like situation is only half of them can taste, so do the parents. Therefore, half of the family can taste the ptc paper.
Finally, as to "please answer it correctly", I believe I did. :)