Which of the following statements is a scientific claim

Albino rabbits (lacking pigment) are homozygous for the recessive c allele (C allows pigment formation). Rabbits homozygous for

Arisa [49]

Answer:

a. If the b and c loci were unliked the expected phenotypic proportions would be:

- 1/4 Brown

- 1/4 Black

- 1/2 Albino

b. The estimated distance between the two loci is equal to 17 centimorgans (cM).

Explanation:

a. If the loci b and c are unlinked or they are not in the same chromosome, it means that b and c are segregated independently (following Mendel's laws). So, the first step is to state the genotypes of the rabbits.

Albino rabbits are homozygous for c (cc)

Brown rabbits are homozygous for b (bb).

Black rabbits have a copy of B (Bb or BB).

But, rabbits have the two genes (b and c), so they could be:

Albino: BBcc/Bbcc/bbcc.

Brown: bbCC/bbCc

Black: BBCC/BBCc/BbCC/BbCc

A cross was made with true-breeding brown rabbits( that means "pure" or homocygotes) bbCC and albino BBcc.

So, we have :

bbCC X BBcc

This is a dihybrid cross with only one possible genotype in F1: BbCc. -> Black rabbits.

After this, these rabbits (BbCc) were crossed with double recessive (albino) rabbits, like this:

BbCc X bbcc

To know the possible outcomes of F2, it is necessary to make a Punnett square 4x4. Following the independent assortment principle, we will have the following possible gametes:

Black Rabbits: Cb, CB, cB,cb.

Double recessive rabbits: cb, cb, cb, cb.

After doing the Punnett square, we will have 4 possible genotypes and 3 possible phenotypes in F2:

1. bbCc = Brown

2 BbCc = Black

3. Bbcc= Albino

4. bbcc= Albino

That means:

1. 1/4 Brown

2. 1/4 Black

3. 1/2 Albino

b. To estimate the distance between the two loci is necessary to use the data provided in the question.

In this case, we are assuming that b and c are in the same chromosome, so they don't follow Mendel's laws. The first step is to know which are the initial genotypes.

The initial cross was between a brown rabbit (bbCC ) and an albino rabbit (BBcc). If the two genes are linked, we can say that in the brown rabbit bC are always together and in the albino Bc will be together, because they're linked.

F1 will be black rabbits bCBc, (remember bC and Bc go always together).

So, after this, a new cross was made with a double recessive:

bCBc X bcbc

The possible outcomes are:

bCbc Brown

Bcbc Albino

As you see, there are not black rabbits, so to find black rabbits, we need to find a BCbc genotype. This genotype can be produced by recombination or crossingover in the same chromosome in parentals. So, the distance between two loci is equal to the proportion of individuals with a recombinant genotype, in this case, BCbc or black rabbits.

So, we have:

34 black

66 brown

100 albino

Total: 200

D $Distance=\frac{Recombinants}{Total } *100= \frac{34}{200}*100= 17 cM$

Estimated distances are measured in centimorgans (cM).

4 0

4 years ago

Covalent bonds are formed when valence electrons are _____ between _____.

Iteru [2.4K]

<h2>Answer:</h2>

Option B is correct.

B. shared; atoms

<h2>Explanation:</h2>

A covalent bond, also called a molecular bond, is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs, and the stable balance of attractive and repulsive forces between atoms, when they share electrons, is known as covalent bonding.

8 0

4 years ago

Read 2 more answers

If a plant has 20 chromosomes, how many chromosomes would you expect to find in a pollen cell from that plant? Be sure to explai

r-ruslan [8.4K]

Answer/Explanation:

We are not told if the plant has 20 chromosomes in total or 20 pairs of chromosomes. E.g. a human has 23 chromosomes, but we are diploid, so there are 46 chromosomes present in most cells.

An exception to the rule is the gametes, or the sex cells, where we are haploid. We have 23 chromosomes in these cells.

Pollen cells in plants are the sex cells. Therefore, they are haploid. If we assume that 20 chromosomes is the haploid number (and there are therefore 20 pairs of chromosomes) then the pollen will have 20 chromosomes.

If we assume that 20 chromosomes is the diploid number (and therefore there are 10 pairs of chromosomes), then the pollen will have 10 chromosomes.

6 0

3 years ago

In the electron transport chain, which structure forms a channel in the inner membrane of the mitochondria and adds phosphate to

Anna35 [415]

Answer: ATP synthase

Explanation:

The ATP synthase complex is an enzyme located in the inner membrane of the mitochondrion that catalyzes the synthesis of ATP from ADP, a phosphate group and energy supplied by a proton (H+) flux. This ATP synthesis occurs during cellular respiration, which is a set of biochemical reactions by which certain organic compounds are completely degraded by oxidation to inorganic substances. This process provides usable energy to the cell in the form of ATP.

During cellular respiration, ATP synthesis is termed oxidative phosphorylation and the proton flux takes place between the intermembrane space and the mitochondrial matrix. <u>ATP synthase produces ATP when protons flow through it</u>. The proton flow creates a pH gradient and an electrochemical gradient. <u>This proton gradient is used by ATP synthase to form ATP via oxidative phosphorylation. ATP synthase acts as an ion channel that "returns" protons to the mitochondrial matrix</u>. During this return, the Gibbs free energy produced during the generation of the oxidized forms of electron transporters is released. This energy is utilized for ATP synthesis. It must then be considered that the electron transport chain and oxidative phosphorylation are coupled by the proton gradient.

3 0

3 years ago

Over the past four decades, researchers have identified many types of ______. Examples include growth factor receptors, transcri

Serhud [2]

Over the past four decades, researchers have identified many types of oncogenes, including growth factor receptors, transcription factors, and intracellular signaling proteins.

<h3>What are oncogenes?</h3>

These are specific genes in an organism that can cause the formation of cancer. These genes are prone to defects that when activate, signal for a cell to become a tumor. The genes listed in the question are some examples of the types of cells that can be oncogenes.

Therefore, we can confirm that over the past four decades, researchers have identified many types of oncogenes, including growth factor receptors, transcription factors, and intracellular signaling proteins.

To learn more about oncogenes visit:

brainly.com/question/7310602?referrer=searchResults

6 0

2 years ago