Answer:
An index fossil is a fossil used to determine the age of the sediments in which it is found. When quickly approximating the age of new finds, an archaeologist looks at the rocks in which it is buried, as those sediments would have been on the surface at the time of the death of the pre-historic creature.
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The two new strands are different from each other ,both of them have only one strand from the original DNA and the other strand is complementary . eg if a strand has the following base pairs .. AACCGGT ( consider this as the strands)
TTGGCCA
now they are going to be seperated AACCGGT TTGGCCA
TTGGCCT AACCGGT
as u can see the two NEW strands formed are similar but NOT IDENTICAL to each other .
The movement of water molecules in and out of a cell is called osmosis.
Osmosis, or the diffusion of water molecules, is when water molecules flow in or out of a cell from high to low concentrations (down their concentration gradient). The ultimate goal of osmosis is to establish equilibrium between the cell and its outer environment.
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Answer:
The reflex arc follows this sequence of events
1. sensory receptor activation
2. sensory neuron activation
3.information processing
4. motor neuron activation
5. effector response
Explanation:
Reflex arc is the pathway of nerves during a reflex action. An example of a reflex arc is when we accidentally touch a hot object. First, the receptor in the skin detects a stimulus in this case the change in temperature. Second, the sensory neuron transmit the electrical impulses to the Central Nervous System for information processing. Then relay neurons connect sensory neurons to motor neurons. Third, motor neurons sends electrical impulses to an effector wherein the effector produces a response ( muscle contracts to move the hand away from the hot object. This happens in a split of seconds.
Answer:
F1 Females - all wild type
F1 Males - all wild type
F2 Females - - all wild type
F2 Males - 1/2 wild type, 1/2 vermilion
Explanation:
The wild-type allele (Xᵛ⁺) is dominant over vermilion (Xᵛ), which is a sex-linked trait.
Female flies have two X chromosomes, male flies have one X and one Y chromosome.
A homozygous wild-type female fly (Xᵛ⁺Xᵛ⁺) is mated with a vermilion male fly (XᵛY).
The female parent can only produce Xᵛ⁺ gametes.
The male parent can produce either Xᵛ or Y gametes.
When gametes from both parents fuse, the F1 offspring will have the genotypes Xᵛ⁺Xᵛ (females with wild type eyes) and Xᵛ⁺Y (males with wild type eyes).
The F1 females can produce Xᵛ⁺ and Xᵛ gametes. The F1 males can produce Xᵛ⁺ and Y gametes.
When the F1 individuals interbreed, the gametes combine to give rise to the F2 offspring. The possible combination of gametes that will give the different genotypes and phenotypes in the F2 are:
- Xᵛ⁺Xᵛ⁺ females with wild type eyes
- Xᵛ⁺ Y males with wild type eyes
- Xᵛ Xᵛ⁺ females with wild type eyes
- Xᵛ Y males with vermilion eyes
