NT
Ninga Tafuna
Answers (8)
NT
Answered
The first federation of industrial unions was known as the ____________________________.
On Aug 02, 2024
Congress of Industrial Organizations
NT
Answered
Which organisms have a hydrostatic skeleton with a soft body wall?
A) sea anemones
B) spiders
C) lobsters
D) crabs
E) cheetahs
A) sea anemones
B) spiders
C) lobsters
D) crabs
E) cheetahs
On Jul 29, 2024
A
NT
Answered
Among critics of the NLRA, the most common belief is that the NLRA is vulnerable to management efforts to exploit deficiencies in the law to their own advantage.
On Jun 30, 2024
True
NT
Answered
The circulatory route that runs from the digestive to the liver is called the ________.
A) pulmonary circulation
B) hepatic portal circulation
C) coronary circulation
D) cerebral circulation
A) pulmonary circulation
B) hepatic portal circulation
C) coronary circulation
D) cerebral circulation
On Jun 27, 2024
B
NT
Answered
The intercostal veins drain blood from the intercostal muscles into the ________ vein.
A) subscapular
B) internal jugular
C) azygous
D) axillary
A) subscapular
B) internal jugular
C) azygous
D) axillary
On May 31, 2024
C
NT
Answered
Imagine you discovered a fossil from an adult organism that you suspect might be an ancient chordate. What structure would you look for to confirm your suspicion?
On May 28, 2024
To confirm the suspicion that a fossil comes from an ancient chordate, you would look for evidence of structures that are characteristic of the chordate phylum. Chordates are a diverse group of animals that include vertebrates (animals with backbones), as well as some invertebrates. The defining features of chordates that you would look for in a fossil include:
1. **Notochord**: A flexible, rod-shaped body that runs the length of the organism's body, providing skeletal support. In many vertebrates, the notochord is replaced by the vertebral column (spine) during development, but evidence of its existence might be found in the fossilized remains.
2. **Dorsal Hollow Nerve Cord**: Unlike other animal phyla that have solid nerve cords, chordates have a nerve cord that is dorsal (on the back) and hollow. In vertebrates, this structure develops into the spinal cord and brain.
3. **Pharyngeal Slits or Pouches**: Openings in the throat area (pharynx) that are used for filter-feeding in invertebrate chordates and are present during the embryonic development of vertebrates. In fish and some amphibians, these slits develop into gills, while in terrestrial vertebrates, they give rise to various structures in the ear and neck.
4. **Post-anal Tail**: An extension of the body past the anal opening. In many chordates, this tail contains skeletal elements and muscles, and it can be quite prominent during some stage of development.
5. **Endostyle or Thyroid Gland**: The endostyle is a glandular groove in the floor of the pharynx that is present in invertebrate chordates, which in vertebrates develops into the thyroid gland.
When examining a fossil for signs of these structures, it's important to note that not all of them may be preserved. Fossilization can preferentially preserve certain types of tissues or structures, depending on the conditions under which the organism was fossilized. Hard structures like bones or shells are more likely to be preserved than soft tissues. Therefore, in the case of a suspected chordate fossil, the most likely features to be identifiable would be the notochord (or vertebral column if it's a vertebrate), and possibly the pharyngeal slits if the conditions allowed for their preservation.
If the fossil shows evidence of any of these structures, it would strongly support the hypothesis that the organism was indeed a chordate.
1. **Notochord**: A flexible, rod-shaped body that runs the length of the organism's body, providing skeletal support. In many vertebrates, the notochord is replaced by the vertebral column (spine) during development, but evidence of its existence might be found in the fossilized remains.
2. **Dorsal Hollow Nerve Cord**: Unlike other animal phyla that have solid nerve cords, chordates have a nerve cord that is dorsal (on the back) and hollow. In vertebrates, this structure develops into the spinal cord and brain.
3. **Pharyngeal Slits or Pouches**: Openings in the throat area (pharynx) that are used for filter-feeding in invertebrate chordates and are present during the embryonic development of vertebrates. In fish and some amphibians, these slits develop into gills, while in terrestrial vertebrates, they give rise to various structures in the ear and neck.
4. **Post-anal Tail**: An extension of the body past the anal opening. In many chordates, this tail contains skeletal elements and muscles, and it can be quite prominent during some stage of development.
5. **Endostyle or Thyroid Gland**: The endostyle is a glandular groove in the floor of the pharynx that is present in invertebrate chordates, which in vertebrates develops into the thyroid gland.
When examining a fossil for signs of these structures, it's important to note that not all of them may be preserved. Fossilization can preferentially preserve certain types of tissues or structures, depending on the conditions under which the organism was fossilized. Hard structures like bones or shells are more likely to be preserved than soft tissues. Therefore, in the case of a suspected chordate fossil, the most likely features to be identifiable would be the notochord (or vertebral column if it's a vertebrate), and possibly the pharyngeal slits if the conditions allowed for their preservation.
If the fossil shows evidence of any of these structures, it would strongly support the hypothesis that the organism was indeed a chordate.
NT
Answered
During arousal, the vagina will secrete a lubricating fluid.
On May 01, 2024
True
NT
Answered
Which of the following is a bone marking that indicates a rounded passageway for blood vessels or nerves?
A) tubercle
B) trochanter
C) foramen
D) process
A) tubercle
B) trochanter
C) foramen
D) process
On Apr 28, 2024
C