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:
Options B.
They are both diploblastic.
Explanation:
Cnidarians are group of aquatic animals that live both in fresh water and Marine water. They are distinguished by the possession of specialized cells called cnidocytes for capturing prey. They are radially symmetrical and have two body layers ectoderm and endoderm separated by jelly layer called mesoglea.
Examples are Hydra, corals, sea anemone and jelly fish.
Ctenophores are phylum of Marine animals that are found in every where. They are characterized by vast of cilia which is use for swimming. They are bilaterally symmetrical , they have mouth and don't have anus. They don't have respiratory, excretory and circulatory system. They are diploblastic i.e they have two body layers but some are triploblastic.
They have nemacyctes for capturing prey.
Examples are nuda, tentaculata e.t.c.
A dichotomous key helps you identify unknown specimens based on their traits because there are only two options available per trait. Selecting one from the two options (usually contrasting characteristics) from each step leads to smaller and smaller groups until the option is reduced to single and unique trait of an organism.
Considering you need to identify an organism. So, on the top of they key is animal with options: (a) with red blood cells and (b) no red blood cells. The option you will select is no red blood cells and under option b, you’re given two choices again: (a) hard bodies and (b) soft bodies. You’ll select soft bodies, then two options again are given: (a) with shell and (b) without shell. The option you’ll select would be without shell, and so on.
The energy from sunlight comes in the form of photons, and this energy is used in the light dependent reactions of photosynthesis. The first function carried out by the photons in energizing electrons in the chlorophyll. The energized electron travels through the electron transport chain and subsequent steps are carried out to utilize this energy to form ATP.
