The main purpose of digestion?

In Drosophila, an autosomal gene determines the shape of the hair, with B giving straight and b giving bent hairs. On another au

klasskru [66]

Answer:

a. F1 genotype : IiBb F1 phenotype : Hairless

F2 genotype and phenotype :

I_B_ (hairless), iiB_ (straight), iibb (bent)

b. IiBb X iiBb

Explanation:

a. Fly 1 : pure breeding straight haired : iiBB

Fly 2 : pure breeding hairless with bent genotype : IIbb

Fly 1 X Fly 2 : iiBB X IIbb = IiBb (F1)

All the offspring will be hairless since there is one dominant I allele which will inhibit hair production regardless of the type of allele of other gene.

Two F1 flies will be crossed to obtain F2 flies. IiBb X IiBb :

I_B_ : hairless = 9

I_bb : hairless = 3

iiB_ : straight hair = 3

iibb : bent hair = 1

Hairless : straight : bent will be in 12 : 3 : 1 ratio.

b. The offspring of this cross :

hairless : I_ _ _

straight : iiB_

bent : iibb

There is a bent offspring which has both the recessive alleles of both the genes. Hence it must have obtained the two alleles from the two parents. So their genotype is _i_b and _i_b.

Half of the offspring are hairless as given by the ratio. This is only possible if the cross is between Ii and ii fly:

I i

i Ii ii

So the genotype is Ii_b and ii_b.

The remaining hairy flies are in 3:1 ratio of straight to bent. This is only possible if the cross is between Bb and Bb fly:

B b

B BB Bb

b Bb bb

So the final genotype of the flies is IiBb and iiBb.

4 0

4 years ago

Question 4

vesna_86 [32]

Answer: Option A) nucleus

Explanation:

Prokaryotic cells lack nuclear envelope, thus the nucleus is absent in Prokaryotic cells.

On the other hand, eukaryotic cells possess membrane bound nucleus and nuclear envelope.

Thus, nucleus is the answer

5 0

4 years ago

This seems really pity I know, but my biology course reading doesn't help answer these questions whatsoever- at least not in a w

blsea [12.9K]

Answer:

1. D- Within cultures that rely on milk-producing animals, individuals who tolerated lactose had a survival advantage.

2. B- Genetic drift is the random increase or decrease of certain genes in a population; natural selection is not random.

3. A- An interferon activates the body's immune system response to a virus.

4. D- Each persons immune system employs different tactics to get rid of the virus.

5. D- yes, because mutated viruses are able to infect more hosts.

i just did this test, 100% with these answers

7 0

3 years ago

When energy is used, ATP molecules convert to ADP molecules.The process is called ___

Anna11 [10]

Geologists have known for about 100 years that the Earth is composed of four layers; the Crust, the Mantle, the Outer Core, and the Inner Core .
Scientists still argue about the makeup of these layers and exactly how each layer interact with the other layers. We are not even sure how the layers were formed but we have some theories.

Because we can not go to the center of the earth we have to find our answers otherwise.

This is what a geologist by the name of Andrija Mohorovicic did. He discovered in 1909 that earthquake waves near the surface moved slower than earthquake waves that passed through the interior of the Earth. He also noticed that the P (primary, first and strongest) waves that passed through the interior of the Earth did not do so in a straight line. These waves were bent or deflected by something! 
What the scientist knew was that waves of all kinds move faster and straighter through denser, more solid objects.
So Mohorovicic came to the conclusion that the outside layer or Crust was made of less dense material (Rock) and the next layer, the Mantle was much denser. This would explain why the earthquake waves moved slower through the crust. 
So by looking at the seismic waves from earthquakes the scientist learned about the crust and the mantle but they also learned about the outer and inner core. 
To do this you have to look at a different kind of waves, the S (secondary waves) waves that also get released by an earthquake. These S waves are slower.
Beno Gutenberg , a German geologist, believed that the Outer Core must be made of a liquid because the slower S waves could not pass through this layer and in fact "bounced off" and were deflected many degrees off course. 
The fourth layer, the Inner Core, is composed of very, very hot metals (iron and nickel) with pressures so great that the metals do not flow as a liquid, but are forced to vibrate in place like a solid. 
Earthquake waves that reach this layer move at the greatest speeds because waves move through solids faster than through gases and liquids. 
This is how we know that there have to be different layers. Otherwise the behavior of the different seismic waves would not make sense.

5 0

4 years ago

Read 2 more answers

While reading an online resource, a student noticed an error in the paragraph below:In photosynthesis, ATP is generated in the l

satela [25.4K]

Answer: ATP and NADPH are produced in the light dependent stage

Explanation:

In the light dependent stage of photosynthesis, photoactivation of chlorophyll results in the splitting of water molecules and the transfer of energy to ATP and reduced nicotinamide adenine dinucleotide phosphate (NADPH).

NADPH and ATP are used to carryout the light-independent stage and not just ATP alone as claimed in the publication.

The phrase that needs correction is "ATP is generated in the light reactions "

5 0

3 years ago