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3 years ago

What three steps did Mendel follow to cross pea plants? (I give out branist!)

Biology

1 answer:

4vir4ik [10]3 years ago

3 0

Answer:

he produced a true-breeding parent generation, then a second generation by breeding two different true-breeding plants, then a third one by self pollinating the plants in the 2nd generation that had similar traits

Explanation:

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Which of these is unique to flowering plants?haploid gametophytes,an embryo surrounded by nutritive tissue,double fertilization,

fiasKO [112]

Answer:

double fertilization

Explanation:

Flowering plants or angiosperms are seed-producing plants with the ability to produce reproductive organs-flowers and fruits with seed in it (unlike gimnosperms which contain naked seed). Another distinctive feature of angiosperms is their reduced gametophytes. This feature most likely reduces the time between pollination and fertilization. Fertilization in flowerin plants is double, meaning that two sperm cells fertilize ovule cells(egg cell and central nuclei cell): one forms diploid zygote which will develop in embryo, while other form triploid cell which will develop into endosperm (provides nutrition for the embryo).

7 0

3 years ago

In Figure 12–5, what nucleotide is going to be added at point 2, opposite from guanine?

Luden [163]

Cytosine is the answer

3 0

3 years ago

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A human fingernail has a hardness of approximately 2.5. Which mineral is softer than a finger nail. A. calcite B. gypsum C. apat

denis23 [38]

According to the 2011 Earth Science Reference Table, Selenite Gypsum has an approximate hardness of 2.

The hardness of calcite is 3.

The hardness of apatite is 5 according to the Moh's hardness scale.

The hardness of diamond is 10.

3 0

3 years ago

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A constant rate of increase (rmax) for a population produces a growth graph that is J-shaped rather than a straight line. Why?

Alexus [3.1K]

Answer:

Explanation:

The line graph illustrates the temperatures in London, New York and Sydney on monthly average and the table introduces the information about the annual hours of sunshine for these cities. The overall view is that London is always exceeded by the rest in both the temperature and the number of sunshine hours.

To specify, the line graph shows that in New York, the average temperature goes up slightly from 4.5 degree in January to 8 degree in March, before a more significant increase to the highest of 30 degree in July, followed by a drop to 5 degree in December. Similarly, in London, after climbing gradually from the lowest point of 9 degree to the highest of 23 degree in July, the figure stays unchanged in the next month and then fall to 9.5 degree in December.

On the contrary, in Sydney, the temperature decrease insignificantly from 25.5 degree in January to the lowest of 16 degree in July, before a gradual rise to 25 degree in December. Meanwhile, the table indicates that New York has the largest number of sunshine hours per year with 2535 hours, came after by Sydney and London with 2473 hours and 1180 hours respectively.

In conclusion, London is likely to be the coldest city because its annual hours of sunshine is less than two others.

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3 years ago

Read 2 more answers

The Offspring produced by a cross between two given types of plants can be any of the three genotypes denoted by A, B, and C. A

ratelena [41]

Complete question:

The offspring produced between two given types of plants can be any of the three genotypes, denoted by A, B and C. A theoretical model of gene inheritance suggests that the offspring of types A, B and C should be in a 1:2:1 ratio (meaning 25% A, 50% B, and 25% C). For experimental verification, 100 plants are bred by crossing the two given types. Their genetic classifications are recorded in the table below.

Genotype Observed frequency

A → 18 individuals

B → 55 individuals

C → 27 individuals

Do these contradict the genetic model?

Use a 0.05 level of significance.

Determine the chi-square test statistic.

Answer:

Do these contradict the genetic model? No, according to the chi-square test, there is not enough evidence to reject the null hypothesis of the population being in equilibrium.

Explanation:

Available data:

Crossed genotypes: two
Genotypes among the offspring; Three → A, B, and C
Expected phenotypic ratio → 1:2:1
Total number of individuals, N = 100
A = 18 individuals
B = 55 individuals
C = 27 individuals

So, let us first state the hypothesis:

H₀= the population is equilibrium for this locus → F(A) = 25%, F(B) = 50%, F(C) = 25%
H₁ = the population is not in equilibrium

Now, let us calculate the number of expected individuals, according to their expected ratio.

4 -------------- 100% -------------100 individuals

1 --------------- 25% -------------X = 25 individuals A

2 -------------- 50% -------------X = 50 individuals B

1----------------- 25%--------------X = 25 individuals C

A B C

Observed 18 55 27
Expected 25 50 25
(Obs-Exp)²/Exp 1.96 0.5 0.16

(Obs-Exp)²/Exp

A) (18 - 25)²/25 = 49/25 = 1.96

B) (55 - 50)² / 50 = 25/50 = 0.5

C) (27 - 25)²/25 = 4/25 = 0.16

Chi square = X² = Σ(Obs-Exp)²/Exp

∑ is the sum of the terms
O are the Observed individuals: 2 in chamber B, and 18 in chamber A.
E are the Expected individuals: 10 in each chamber

X² = ∑ ((O-E)²/E) = 1.96 + 0.5 + 0.16 = 2.62

Freedom degrees = 2

Significance level, 5% = 0.05

Table value/Critical value = 5.99

X² < Critical value

2.62 < 5.99

These results suggest that there is not enough evidence to reject the null hypothesis. We can assume that the locus under study in this population is in equilibrium H-W.

6 0

3 years ago