Answer:
False
Explanation:
The blood brain barrier (BBB) is a selective border that prevents the entry of foreign substances into the brain. It is made up of different components including endothelial cells, astrocytes, and pericytes etc.
Of all these mentioned three, the endothelial cells are directly responsible for the selectivity of the BBB. The endothelial cells are bound together by the tight junctions situated between them, impeding the passage of foreign materials e.g. solutes, pathogens etc.
Astrocytes help to maintain the BBB by surrounding the endothelial cells, providing biochemical strength.
The pericytes are located in the basement membrane, where they communicate with endothelial cells. They help to sustain the BBB by stabilizing and monitoring the maturation of endothelial cells via communicating directly between cell membrane as well as paracrine signalling.
Answer:
The flowering population is in Hardy Weinberg equilibrium.
Step by Step Explanation:
Total initial population size = 60
As both the populations are homozygous so the frequency of alleles will be,
P = 80/120= 0.66
q = 40/120= 0.33
The predicted frequencies for genotypes once the population has reached Hardy-Weinberg
p2 = 0.4356
2pq= 0.4356
q2 = 0.1089
The number of plants with each type of flower in a papulation of 420 is,
Homozygous dominant= 185
heterozygous= 185
Homozygous recessive= 50
Chi square analysis:
The observed values for red-flowered plants, pink-flowered plants, and white-flowered plants are not significantly different from the expected values predicted by Hardy Weinberg equilibrium.
Phenotype observed(o) expected (e) (o-e)2/e
Red 178 185 0.26
Pink 190 185 0.135
White 52 50 0.08
chi-square = 0.474
With 2 degree of freedom this chi-square gives a p value of 0.7 - 0.8, which is not significant.
Answer:
In a 2004 long-term prospective report, the United Nations Population Division projected the world population would peak at 9.22 billion in 2075. After reaching this maximum, it would decline slightly and then resume a slow increase, reaching a level of 8.97 billion by 2300, about the same as the projected 2050 figure.Explanation:
Answer:
The possible genotype of the normal male: AA or Aa
The genotype of affected female: "aa"
The probability of having a carrier girl child= 1/4
Explanation:
The given trait is autosomal recessive. Let's assume that the recessive allele "a" is responsible for the trait while the dominant allele "A" gives the dominant phenotype. The genotype of the normal male can be AA or Aa while that of the affected female would be "aa"
Their daughter has dominant phenotype and therefore, would be heterozygous for the trait with "Aa" genotype. A cross between carrier daughter "Aa" and her carrier male "Aa" would give progeny in following ratio= 1/4 AA: 1/2 Aa: 1/4 aa. Therefore, they have 1/2 probability of having a carrier child.
The probability of having a girl child is always 1/2.
So, the total probability of having a carrier girl child would be 1/2 Aa x 1/2 XX = 1/4
Answer:
Fermentation is a metabolic process that produces chemical changes in organic substrates through the action of enzymes. (I'm not sure if is correct? hope this is a correct)
