Which of the following is not one of the three energy sources for the earth system?

What novel characteristics are shared by gymnosperms and angiosperms but not by mosses and ferns?

sergejj [24]

Explanation:

Mosses go through sporophyte and gametophyte stages in their life cycle. ... However, mosses are nonvascular while ferns are vascular. Gymnosperms and angiosperms are both vascular, seed-bearing plants. However, gymnosperms release their seeds in cones (like pinecones) while angiosperms release their seeds through flowers.

3 0

3 years ago

When pink sweet peas were self-pollinated and the seeds were collected and sown, the following flower colors were obtained: Red

Pavlova-9 [17]

Answer:

c. 1:2:1

The results are consistent with incomplete dominance for this trait, with pink flowers being heterozygous.

Explanation:

If flower color were determined by a gene showing incomplete dominance, the possible genotypes and phenotypes are as follows:

RR- red
ww - white
Rw - pink

If pink sweet peas are self-pollinated, then a cross between two heterozygous individuals is done (Rw x Rw).

From this cross the expected ratios are:

1/4 RR (red)
2/4 Rw (pink)
1/4 ww (white)

So the null hypothesis is that the observed results exhibit a 1:2:1 ratio.

<h3>Chi square test</h3>

$X^{2} = \sum \frac{(Observed - Expected)^2}{Expected}$

The observed frequencies were:

34 Red
76 Pink
40 White

Total 150

The expected frequencies for our null hypothesis are:

1/4 x 150 = 37.5 Red
2/4 x 150 = 75 Pink
1/4 x 150 = 37.5 white

$X^{2} = \frac{(34- 37.5)^2}{37.5} + \frac{(76- 75)^2}{75} + \frac{(40- 37.5)^2}{37.5}$

$X^2=0.5067$

The degrees of freedom (DF) are calculated as number of phenotypes - 1; in this case DF = 3-1 = 2.

If we look at the Chi square table, for 2 DF and a probability of p0.05, the critical value is 5.991

Our X^2 value of 0.5067 is less than the critical value, so we do not reject the null hypothesis. The results are consistent with incomplete dominance for this trait, with pink flowers being heterozygous.

8 0

3 years ago

You are doing research on a bacterial species, trying to determine the nature and structure of a number of intracellular inclusi

Mashcka [7]

Answer:

Transmission Electron Microscope.

5 0

3 years ago

How does pH and temperature affect cellular respiration?

Ray Of Light [21]

PH – depends on the environment the cell that is respiring is in.

Temperature; as it increases, the rate increases…to a point (too hot and enzymes denature!)

4 0

3 years ago

Why is it important for the chromosomes to condense during mitosis?

likoan [24]

Answer:

It is important for the chromosomes to condense during mitosis to facilitate chromosome movement.

Explanation:

The chemical called colchicine is found to be used during the process of mitosis, so as to freeze the cells, which can stop or prevent the movement of the chromosomes. This process is also essential for the faithful genome replication or transmission to those daughter cells. During the interphase cell division occurs but during the prophase the cell condensation is found to be happening. Before the process of the mitosis chromosomes are allowed to move and during this entangled and breaking were also noticed.

3 0

3 years ago