Make up a mnemonic device to help you remember the steps of the cell cyle.

From a Punnett square you can get the genotypic and phenotypic proportions of the progeny produced from a cross. Cross: PpRr x PpRr. F1: PPRR, PPRr, PPRr, PPrr, PpRr, Pprr, ppRR, ppRr, pprr.

<h3>What is a Punnett square?</h3>

The Punnett square is a graphic representation that shows the different types of gamete combinations according to the alleles involved in a cross.

Punnett square shows the probabilities of getting offspring with different genotypes and their consequent phenotypes.

In the exposed example, we know that two genes are involved in the cross.

As we can see, there are dominant and recessive alleles for both genes.

Since each genotype in the square results from the combination of parental gametes, we can figure out which are the parental genotypes.

For instance, let us consider the provided genotypes

PPRr.

We can assume one of the parents provided a P and a R dominant alleles, while the other parent provided another P allele but a r recessive allele.

PR + Pr ⇒ PPRr

ppRr.

One of the parents provided a p recessive allele and a R dominant allele, The other parent provided another p allele and a r recessive allele.

pR + pr ⇒ ppRr

pprr.

Both parents provided p and r recessive alleles.

pr + pr ⇒ pprr

From this information, we can assume parents are heterozygous for both genes.

Cross:

Parentals) PpRr x PpRr

Gametes) PR, Pr, pR, pr PR, Pr, pR, pr

Punnett square) PR Pr pR pr

PR PPRR PPRr PpRR PpRr

Pr PPRr PPrr PpRr Pprr

pR PpRR PpRr ppRR ppRr

pr PpRr Pprr ppRr pprr

F1) 1/16 individuals are expected to be PPRR

2/16 individuals are epected to be PPRr

1/16 individuals are expected to be PPrr

2/16 individuals are expected to be PpRR

4/16 individuals are expected to be PpRr

2/16 individuals are expected to be Pprr

1/16 individuals are expected to be ppRR

2/16 individuals are expected to be ppRr

1/16 individuals are expected to be pprr

For a better understanding, you will find the Punnett square in the attached files representing the parental gametes with different colors, and the resulting genotypes with a combination of these colors.

In this way, you will notice which gamete comes from which parent.

You can learn more about Punnett squares at

brainly.com/question/25357981

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5 0

1 year ago

How does the immune system function?

professor190 [17]

Answer:

Immune system of the body helps in fighting with the infectious agents that are foreign for the body. So the immune system protects us from infection.

When any foreign substance(antigen) comes in the body B-lymphocyte recognize it by binding the antigen through its receptor. After recognizing the antigen, B cell divides into antibody-producing plasma cell and memory cell.

Antibodies produced by plasma cells help in destroying the antigen by getting the antigen recognized by phagocytic cells or by complement activation.

B cells are antigen-presenting cell which present antigen to T cell and then T cell activates and produce chemicals that kill the antigen. Therefore the immune system has many immune cells that activate when an antigen comes in the body. This is how the immune system functions.

3 0

3 years ago