Where do echinoderms live?

Interpret the Punnett square. A Punnett square with four rows and four columns. The first row is labeled big-A, big-B. The secon

Naddika [18.5K]

Answer:

The genotypes shown represent gametes. False

One of the possible offspring genotypes is AABB. True

The parent genotypes are ABAbaBab×ABAbaBab. True

This cross shows two alleles for two traits. True

The gametes are diploid and the offspring are diploid. False

The genotypes shown are correct for a dihybrid cross. True

Explanation:

║ AB ║ Ab ║ aB ║ ab

AB║ABAB ║ ABAb║ABaB║ABab

Ab║ AbAB║ AbAb ║AbaB║Abab

aB║aBAB ║ aBAb ║aBaB║aBab

ab║abAB ║ abAb ║abaB ║abab

Drawing the Punnett square we can deduce that the genotypes shown do not represent gametes because there are more than 2 pairs of chromosomes.

As shown in the second column second row of the Punnett square one of the possible genotypes is AABB, it is distributed different (ABAB) but it is the same possible genotype.

The parents' genotypes are the ones that are written in the first columns and first row, they coincide with the ones in the statement.

A dihybrid cross shows the cross between two genes that have different traits.

The gametes are always haploid and the offspring are diploid because the two gametes come together.

7 0

3 years ago

Seedless bananas were probably first caused by a blank

lana [24]

In animals and plants, there are two pairs of chromosomes - one set from a male and the other set from a female. But occasionally, the original fertilized cell doesn't quite divide correctly and more than two sets arises. The fertilized cell continues to divide with the result that all the cells have the extra set of chromosomes. This happens much oftener in plants and the plant will be sterile and can't form seeds.

6 0

4 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).

5 0

3 years ago

The key evolutionary development of animals seen for the first time in sponges is that of

Digiron [165]

The key evolutionary development of animals seen for the first time in sponges is that of Multicellularity. A Multicellular organism has a longer lifespan than an unicellular organism and since it has multiple cells, it can perform more functions. Sponges do not have distinct circulatory, respiratory, digestive, and excretory systems – instead the water flow system supports all these functions.

4 0

4 years ago

Read 2 more answers

What is the difference between climate change and climate variability

vaieri [72.5K]

Answer:

Climate change is the change of temperature in the worlds climate system and climate variability is the variations in a certain climate that last longer then certain weather events.

Explanation:

To explain more climate change is the change in the daily weather in a area for example rain forest to desert or cold to hot climate change goes along with global warming which is the heating of our Earth which causes ice to melt in the arctic rising our sea levels creating stronger storms. While in a climate variability its only a certain time of that specific climate change for example its only cold for a certain period of time then the temperature rises to hot again. So, the key difference is that "climate change is the change of temperature in the worlds climate system and climate variability is the variations in a certain climate that last longer then certain weather events."

Hope this helps!

8 0

3 years ago