Answer: 1/16, or approximately 6.25% (see explanation below)
Explanation:
Answering this question requires two steps.
First, we need to figure out the probability that this couple will have a child with albinism in the first place. We know the following:
- Both parents are unaffected.
- The couple has already had one affected child.
- Albinism follows an autosomal recessive inheritance pattern.
Let ( M = normal gene ) and ( m = mutated gene ). Since the condition is recessive, the affected child can be assumed to have a “mm” genotype. Barring the possibility of a de novo mutation (which are assumed to be rare), the affected child must have inherited one ”m” allele from each parent. Since both of them are unaffected, however, we can assume that they are both carriers (genotype “Mm”). In conclusion, 1/4 of their offspring (25%) <em>for any given pregnancy</em> may be expected to have albinism. See the resulting Punnett square:
<u> | M | m </u>
<u>M | MM | Mm </u>
<u>m | Mm | mm </u>
Note that the question asks about the probability that not one but two consecutive births result in affected children. Since it can be assumed that both events are independent (meaning: the outcome of a pregnancy does not influence the outcome of following ones), we may apply the rule of multiplication for probabilities. The final answer is therefore 1/4 * 1/4 = 1/16.
Answer:
Trees have to adapt to their environments in order to survive them, from the shape of their leaves to the size of their branches. They also have had to adapt the shape of their crowns to the kind of climate they live in so that they may have better chances at survival.
In warm areas with lots of sunlight for instance, you will see broad cones as the tree takes advantage to get as much sunlight as it can. In colder areas where snow is abundant, trees will be conical in shape so as not to gather too much snow when it falls.
Answer:
Neurons have stable, relatively unchanging internal environments.
Explanation:
Neurons or nerve cells is the structural and functional unit of the nervous system. Neurons consists of the dendrites, axon, cell body and different cell organelles.
The neurons have mitochondria that meets the high ATP requirement and and consume more oxygen. The network of rough endoplasmic reticulum and ribosomes produce large number of proteins in neuron. The internal environment is never stable and gets changed as the nerve impulse transmission occur through the neuron. The membrane potential of the neuron gets changed and changes its internal environment.
Thus, the correct answer is option (B).
Interphase- D prophase-C anaphase-A telophase/cytokinesis-E
The difference between extrusive and intrusive rocks are how they cool
down. Extrusive rocks cool down quickly and are created by lava; because
of this they have very small, fine-grained crystals. Intrusive rocks
cool slowly beneath the surface of the earth and are created by magma;
because the cooling process is very slow the rocks have very large
crystals.
