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3 years ago

Which of the following phrases characterizes alternation of generation in algae?

Biology

2 answers:

Natalija [7]3 years ago

8 0

Answer

The correct answer would be "Diploid sporophytic generation alternating with haploid gametophytic generation"

Alternation of generation refers to the type of life cycle often observed in lower plants. In this life cycle, plants alternate between diploid and haploid stage.

For example, a diploid sporophyte produces haploid spores through meiosis

The spores mature into haploid gametophyte which produces haploid gametes through mitosis.

The gametes fertilize and restore the ploidy by producing a diploid zygote which matures into a diploid sporophyte.

grin007 [14]3 years ago

6 0

Diploid sporophytic generation alternating with haploid gametophytic generation <span>phrases characterizes alternation of generation in algae.</span>

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The increase in blood flow to exercising active skeletal muscle relative to other organs is largely caused by the

defon

Answer:

muscle contraction increases interstitial fluid pressure and compresses the blood vessels within the active muscle. As a consequence, blood flow is highest when muscles relax between successive muscle contractions.

Explanation:

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2 years ago

2. In Squidward's family, a blue body color (B) is dominant to green (b). Determine the phenotype for each

sveta [45]

BB and Bb would be blue because they are both dominant and bb would be green because it is recessive

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3 years ago

Cystic fibrosis (CF) is one of most common recessive disorders among Caucasians it affects 1 in 1,700 newborns. What is the expe

Phantasy [73]

Answer: The expected frequency of carriers is P(Aa)=0.046.

The proportion of childs with CF is P(aa)=0.024.

25% of having a child with CF (aa).

Explanation:

Hardy-Weinberg's principle states that in a large enough population, in which mating occurs randomly and which is not subject to mutation, selection or migration, gene and genotype frequencies remain constant from one generation to the next one, once a state of equilibrium has been reached which in autosomal loci is reached after one generation. So, a population is said to be in balance when the alleles in polymorphic systems maintain their frequency in the population over generations.

Given the gene allele frequencies in the gene pool of a population, it is possible to calculate the expected frequencies of the progeny's genotypes and phenotypes. <u>If P = percentage of the allele A (dominant) and q = percentage of the allele a (recessive)</u>, the checkerboard method can be used to produce all possible random combinations of these gametes.

Note that p + q = 1, that is, the percentages of gametes A and a must equal 100% to include all gametes in the gene pool.

The genotypic frequencies added together should also equal 1 or 100%, and all the equations can be summarized as follows:

$p+q=1\\(p+q)^{2} = p^{2} +2pq+q^{2} = 1\\P(AA)=p^{2} \\P(aa)=q^{2} \\P(Aa)=2pq1$

So, there are 1700 individuals and only one is affected. Since it is a recessive disorder, the genotype of that individual must be aa. So the genotypic frequency of aa is 1/1700=0.000588.

Then, $P(aa)=q^{2}=0.000588$ . And with that we can calculate the value of q,

$P(a)=q=\sqrt{0.000588}=0.024$

And since we know that p+q=1, we can find out the value of p.

$p+0.024=1\\1-0.024=p\\p=0.976$

Next, we find out the genotypic frequency of the genotype AA:

$P(A)=p=0.976\\P(AA)=p^{2} = 0.976^{2}=0.95$

Now, we can find out the genotypic frequency of the genotype Aa:

$P(Aa)=2pq=2 x 0.976 x 0.024 = 0.046$

Notice than:

$p^{2} + 2pq + q^{2} = 1\\x^{2} 0.976^{2} + 2 x 0.976 x 0.024 + 0.024^{2} = 1$

Then, the expected frequency of carriers is P(Aa)=0.046

The proportion of childs with CF is P(aa)=0.024

If two parents are carriers, then their genotypes are Aa.

Gametes produced by them can only have one allele of the gene. So they can either produce A gametes, or a gametes.

In the punnett square, we can see that there genotypic ratio is 2:1:1 and the phenotypic ratio is 3:1. So, there is a probability of 25% of having an unaffected child, with both normal alleles (AA); 50% of having a carrier child (Aa) and 25% (0.25) of having a child with CF (aa).