<span>Answers;
1.Breeding of individuals that have genes for two different characteristics; Dihybrid cross
2.A grid system used to predict possible combinations of genes due to random fertilization; Punnet square
3 A condition in which both alleles are dominant; Codominance
4.when more than two alternatives exist for a gene; multiple alleles
5.A condition in which neither pair of alleles is dominant or recessive, so the traits blend in the phenotype ;Incomplete dominance;
Explanation;
</span>Dihybrid cross;
<span>It involves the breeding of individuals that have genes for two different characteristics. It involves the cross of individuals that are both heterozygous for two different traits. For example two different traits in a pea plant; color and shape; for color we have; Y-allele for yellow seeds and y- allele for green seeds, For Shape trait; R-allele for round seeds and r-allele for wrinkled seeds. So the dihydbrid cross would be (RrYy </span>× RrYy).
<span>
Punnet square;
</span><span>This a grid system or a square diagram that is used to predict possible combinations of genes due to random fertilization. It is used by biologists determine the probability of an offspring having a particular genotype.
</span><span>The letters on the outside of a Punnett Square stand for the parent allele.
</span>
Codominance;
<span>This is a condition in heterozygotes in which both members of an allelic pair are dominant and both contribute to the phenotype.
A good example of codominance is the ABO blood group; A person with blood group AB, it means that both the A allele and B allele are equally expressed.
Multiple alleles
</span><span>This is when more than two alternatives for a gene exist.
Examples of multiple allelism in human;The genes of the ABO blood group system. The human ABO system is controled by three alleles, namely; A-allele, B-allele and O-allele.
Incomplete dominance;
</span><span>This is condition in heterozygotes in which both members of an allelic pair are neither dominant nor recessive to other alleles, so the two traits blend in the phenotype of the individual.
An example; is a snapdragon flower that is pink as a result of cross-pollination between a red flower and a white flower. Which means neither the white allele or the red allele are dominant. </span>
Answer:
d. malleus > incus > stapes > oval window
Explanation:
Sound waves enter external auditory canal which makes the eardrum to vibrate. Malleus is in contact with eardrum while stapes is in contact with the oval window. Movement of malleus makes the incus to move which in turn stimulates large movement in stapes.
Since stapes is in contact with the oval window, the vibration from stapes passes to the oval window. Hence, among the given options, the correct order of movement of sound waves is "malleus > incus > stapes > oval window"
.
DNA
1. Found in nucleus
2. Sugar is deoxyribose
3. Bases are A, T, C, and G
RNA
1. Found in nucleus and cytoplasm
2. Sugar is ribose
3. Bases are A, U, C, and G
Answer:
Signal transduction pathways
Explanation:
Plant hormones act by directly affecting the activities of signal transduction pathways.
Signal transduction pathways are involved in the transfer of signals from outside of the cell to the inside of the cell for the regulation of various cellular activities. For this, the extracellular signalling molecules bind to the receptors that are located on the cell membrane. After their binding due to some change in the receptor molecule, a signal is triggered in to the cell and thus information from outside of the cell is transferred to the inside of the cell through these transduction pathways.
Plant hormones affect these pathways and as a result membranes, enzymes, and genes are also influenced by the plant hormones.
B. Ice-albedo feedback
Explanation:
The ice-albedo feedback is one process that can significantly increase the rate of greenhouse emissions in response to a decreased albedo.
Albedo is the ratio of reflected light to incident light.
A decrease in albedo suggests that a surface is absorbing more light than it is reflecting. This is typical of areas with land cover and vegetation.
Areas with a high reflectivity have a high albedo. Snow, ice and polar regions are good reflectors of solar radiation. They have a very high albedo close to 100%. Much of the surface area is buried with ice.
Examples of greenhouse gases are carbon dioxide, methane, water vapor e.t.c
How does a low albedo relates to increase in greenhouse gas emission?
- The ice-albedo feedback can substantially contribute to greenhouse gas emission.
- The high reflectivity of ice causes long wave radiation to warm the air around a icy body in polar regions.
- When ice melts, they leave land bare and exposed.
- Melt water collects in pockets.
- Exposed land leads to a decrease in albedo.
- Organisms can thrive more in warm terrain.
- Also, pockets of carbon dioxide gases trapped in ice is released.
- Organisms release carbon dioxide into the atmosphere during cellular respiration.
- Soils originally permafrost will become stable and this will encourage more human occupation of the area.
- All these activities leads to an increase in the emission of greenhouse gases in an area with low albedo.
Learn more:
Greenhouse emission brainly.com/question/4580761
#learnwithBrainly
