Answer:
Guard cells perceive and process environmental and endogenous stimuli such as light, humidity, CO2 concentration, temperature, drought, and plant hormones to trigger cellular responses resulting in stomatal opening or closure.
Explanation:
Answer:
When a warmer air mass travels over colder ground, the bottom layer of air cools and, because of its high density, is trapped near the ground. In general, cold air masses tend to flow toward the equator and warm air masses tend to flow toward the poles. This brings heat to cold areas and cools down areas that are warm
During the transfer of energy from one tropic level to the next tropic level around 90% of the total energy is lost in the metabolic processes in the form of heat. Hence only about 10% of the total energy can only be transferred from one tropic level to the next tropic level.
Answer:
e. Red segregated from brown in meiosis I, and straight segregated from curled in meiosis I.
Explanation:
A cross between two flies heterozygous for both genes produced an offspring with the phenotypic ratio of 9:3:3:1. This ratio is expected according to Mendel's law of independent assortment, which states that alleles of the same gene assort independently during gamete formation.
Before meiosis starts in flies, a single diploid cell duplicates its DNA, so each chromosome has 2 sister chromatids that contain the same information.
- During meiosis I, <u>the homologous chromosomes separate</u> into two daughter cells. The chromosome number is reduced by half, but each chromosome has two sister chromatids.
- During meiosis II, <u>the sister chromatids separate</u> and each daughter cell from meiosis I divides into two new daughter cells (to get the total of 4 haploid cells).
In a heterozygous fly, each homologous chromosome contains a different allele, and the sister chromatids are copies that carry the same allele. For that reason, both traits were segregated during meiosis I.
Answer:
the internal organ in which the major part of the digestion of food occurs, being (in humans and many mammals) a pear-shaped enlargement of the alimentary canal linking the esophagus to the small intestine.
