When a cell divides, it is important that each daughter cell receives an identical copy of the DNA. ... This model for replication suggests that the two strands of the double helix separate during replication, and each strand serves as a template from which the new complementary strand is copied
Complete question:
1). Determine the character states for the following six characters that are present in species OG, 5, 7, 15, 17, 18. Assign the character state found in the outgroup (OG) as a 0 and the alternative derived state a 1; use only two states per character. Example, stem width: 0 = thin, / = thick 1 <em>(Characters and plant species image in the attached files)</em>
2). Score each taxon using the 0 and 1 notation about and add to this matrix <em>(Matrix in the attached files)</em>
4). Reconstruct the phylogeny that most simply and accurately accounts for the distribution of synapomorphies among ingroup species. Given matrices as small and simple as the above example, one can build the tree from the bottom up in a series of sketches, adding clades or branches representing groups with the fewest synapomorphies near the base of the tree and those with the most at the tips. Using the unlabeled phylogeny as a starting point, draw the stepwise construction of a fully resolved phylogeny to account for all of the synapomorphies and include the synapomorphies that identify each clade (the first one, character 2, is included to get you started; this is shared by all members of the ingroup) (<em>Tree in the attached files)</em>
Answer:
- Stem width: Thick-1 // Thin-0
- Leaf edge (shape): Pointed-1 // Blunt-0
- Flower base (shape): Narrow-0 // Wide-1
- Flower orientation: Downward (Pendant)-1 // Upward (Vertical)-0
- Petal color: Purple-1 // Yellow-0
- Fruit shape (inset on card, on left): Round-0 // Elongated-1
- Complete Matrix in the attached files
- Order in the phylogeny reconstruction: OG --> 7 --> 5 --> 15 --> 17 and 18 (tree + evolutive changes in the attached files)
Explanation:
<em>NOTE: You will find the complete activity in the attached files. </em>
- The principle of maximum parsimony or maximum simplicity states that among all possible trees within a group of species, the most probable is the one that requires us to postulate the least number of evolutionary changes. So, to reconstruct a phylogeny we need to choose the tree that requires the less number of changes.
- To determine the character states for all the six characters, we assigned the number cero to all the characters expressed in the out-group. Thin steam, blunt leaf, narrow flower base, upward flower orientation, yellow petals, and rounded-seeds are all cero states. The other characters are 1.
- The above information of character state was used to fill in the matrix, specifying which character state belongs to each species according to their traits.
- The matrix was useful to reconstruct the phylogeny, to identify the autapomorphic trait, and to visualize all the clades.
The answer is prophase of meiosis I.
Meiosis is a reducing cell division during which the number of chromosomes is reduced by half in the daughter cells. It consists of meiosis I and meiosis II. Major gene reshuffling takes place during meiosis I. This exchange of genetic material between homologous chromosomes is known as the crossover. Homologous chromosomes are present only in the meiosis I. They pair up during prophase of meiosis I. When they are paired up during prophase I, it is obviously that gene reshuffling takes place during prophase I.
PARTHENOGENESIS
The females lay unfertilized eggs that develop into females.
The statements that
apply are;
Say to the patient, "Step aside and I will get you
connected to the internet."
Ask the patient, "How were you feeling when you were
having this difficulty?"
Encourage the patient to recognize signs of mounting tension
and seek assistance.