The bile is produced by the liver and the gallblader only serves as storage between meals. The main stimulus for the release of bile from the gallblader comes from the nervous system,after food is put in the mouth.
Answer:
1- Option A) describes an index fossil. Trilobite existed for a short time, but was abundant and lived in many locations.
2- Option B) Continents were once joined and have since drifted apart.
Explanation:
1) Fossils are animal and vegetable rests found in different strata of sedimentary rocks. Sedimentary layers deposit chronologically, so they are used to reflect history. They keep in each layer some of the forms of life that inhabited that area in the past. These fossils turn to be very useful while dating ages. The term Index fossils refer to those fossils that only existed in a given era or geological period during evolution.
Index fossils must:
• Be easily recognizable and distinguishable from all the other fossils
• Have lived in a relatively short geological period
• Present a wide geographic distribution
• Have lived in different sedimentary basins
• Appear in different types of rocks
• Be abundant
<em>A) Trilobite existed for a short time, but was abundant and lived in many locations. </em>The species accomplish the requirements. It is easily recognizable, had a wide geographic distribution, was abundant, and lived for a short time.
2) The tectonic plates theory states that there is a continual movement of the crust. It explains the movement of the different plates and their directions and interactions. The continental drift theory explains how these movements have been taking place since millions of years ago. When continents were together in a unique continent, many species used to inhabit it. When plates started to separate, they took some of these species that got apart by the ocean. Some species were already dead and fossilized, while some other organisms died during continental drift and got fossilized after the divergence. <em>The existence of the same fossils, placed in the same layers and of the same age, suggests that they used to inhabit the same area and died during the same time, meaning that continents were together when they got fossilized. </em>
Answer:
B. Plants in the desert would have a decreased number of stomata compared to rainforest plants.
Answer:
The result of cross two squashes with yellow seeds is an offspring of squash with green seeds -dominant caracter- heterozygous and yellow seeds squashes in a genotype proportion 1:2:1 and phenotype proportion 3:1
Explanation:
The cross of two heterozygous individuals for a characteristic results in an offspring that will have both characteristics in pure and heterozygous form. It is a cross monohybrid which complies with the principle of independent segregation exposed by Mendel.
For the characteristic "seed color" the green color would be G and yellow represented as g.
At the cross of two heterozygous squashs:
- Parents: Gg X Gg
- <u>Punnett's Square</u>:
Alleles G g
G GG Gg
g Gg gg
Offspring:
- A pumpkin of green seeds GG (25%)
- Two pumpkins of green heterozygous seeds Gg (50%)
- One pumpkin of yellow seeds gg (25%)
Genotype proportion 1:2:1
Phenotype proportion 3:1
